diff --git a/.gitignore b/.gitignore
index 89987b1..263eaea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.log
 RCS
 *~
+.vscode
 .*.swp
 .*.swo
 .DS_Store
@@ -46,3 +47,6 @@ unit_level_testbench/pic/workspace/simulation/sim
 tools/codegenerators/AAPGV2/swerv/asm/out*
 tools/codegenerators/AAPGV2/swerv/bin/out*
 tools/codegenerators/AAPGV2/swerv/objdump/out*
+
+obj_dir
+build
diff --git a/test/helloworld/JSON.pm b/test/helloworld/JSON.pm
new file mode 100644
index 0000000..6fb7a90
--- /dev/null
+++ b/test/helloworld/JSON.pm
@@ -0,0 +1,2267 @@
+package JSON;
+
+
+use strict;
+use Carp ();
+use base qw(Exporter);
+@JSON::EXPORT = qw(from_json to_json jsonToObj objToJson encode_json decode_json);
+
+BEGIN {
+    $JSON::VERSION = '2.53';
+    $JSON::DEBUG   = 0 unless (defined $JSON::DEBUG);
+    $JSON::DEBUG   = $ENV{ PERL_JSON_DEBUG } if exists $ENV{ PERL_JSON_DEBUG };
+}
+
+my $Module_XS  = 'JSON::XS';
+my $Module_PP  = 'JSON::PP';
+my $Module_bp  = 'JSON::backportPP'; # included in JSON distribution
+my $PP_Version = '2.27200';
+my $XS_Version = '2.27';
+
+
+# XS and PP common methods
+
+my @PublicMethods = qw/
+    ascii latin1 utf8 pretty indent space_before space_after relaxed canonical allow_nonref
+    allow_blessed convert_blessed filter_json_object filter_json_single_key_object
+    shrink max_depth max_size encode decode decode_prefix allow_unknown
+/;
+
+my @Properties = qw/
+    ascii latin1 utf8 indent space_before space_after relaxed canonical allow_nonref
+    allow_blessed convert_blessed shrink max_depth max_size allow_unknown
+/;
+
+my @XSOnlyMethods = qw//; # Currently nothing
+
+my @PPOnlyMethods = qw/
+    indent_length sort_by
+    allow_singlequote allow_bignum loose allow_barekey escape_slash as_nonblessed
+/; # JSON::PP specific
+
+
+# used in _load_xs and _load_pp ($INSTALL_ONLY is not used currently)
+my $_INSTALL_DONT_DIE  = 1; # When _load_xs fails to load XS, don't die.
+my $_INSTALL_ONLY      = 2; # Don't call _set_methods()
+my $_ALLOW_UNSUPPORTED = 0;
+my $_UNIV_CONV_BLESSED = 0;
+my $_USSING_bpPP       = 0;
+
+
+# Check the environment variable to decide worker module.
+
+unless ($JSON::Backend) {
+    $JSON::DEBUG and  Carp::carp("Check used worker module...");
+
+    my $backend = exists $ENV{PERL_JSON_BACKEND} ? $ENV{PERL_JSON_BACKEND} : 1;
+
+    if ($backend eq '1' or $backend =~ /JSON::XS\s*,\s*JSON::PP/) {
+        _load_xs($_INSTALL_DONT_DIE) or _load_pp();
+    }
+    elsif ($backend eq '0' or $backend eq 'JSON::PP') {
+        _load_pp();
+    }
+    elsif ($backend eq '2' or $backend eq 'JSON::XS') {
+        _load_xs();
+    }
+    elsif ($backend eq 'JSON::backportPP') {
+        $_USSING_bpPP = 1;
+        _load_pp();
+    }
+    else {
+        Carp::croak "The value of environmental variable 'PERL_JSON_BACKEND' is invalid.";
+    }
+}
+
+
+sub import {
+    my $pkg = shift;
+    my @what_to_export;
+    my $no_export;
+
+    for my $tag (@_) {
+        if ($tag eq '-support_by_pp') {
+            if (!$_ALLOW_UNSUPPORTED++) {
+                JSON::Backend::XS
+                    ->support_by_pp(@PPOnlyMethods) if ($JSON::Backend eq $Module_XS);
+            }
+            next;
+        }
+        elsif ($tag eq '-no_export') {
+            $no_export++, next;
+        }
+        elsif ( $tag eq '-convert_blessed_universally' ) {
+            eval q|
+                require B;
+                *UNIVERSAL::TO_JSON = sub {
+                    my $b_obj = B::svref_2object( $_[0] );
+                    return    $b_obj->isa('B::HV') ? { %{ $_[0] } }
+                            : $b_obj->isa('B::AV') ? [ @{ $_[0] } ]
+                            : undef
+                            ;
+                }
+            | if ( !$_UNIV_CONV_BLESSED++ );
+            next;
+        }
+        push @what_to_export, $tag;
+    }
+
+    return if ($no_export);
+
+    __PACKAGE__->export_to_level(1, $pkg, @what_to_export);
+}
+
+
+# OBSOLETED
+
+sub jsonToObj {
+    my $alternative = 'from_json';
+    if (defined $_[0] and UNIVERSAL::isa($_[0], 'JSON')) {
+        shift @_; $alternative = 'decode';
+    }
+    Carp::carp "'jsonToObj' will be obsoleted. Please use '$alternative' instead.";
+    return JSON::from_json(@_);
+};
+
+sub objToJson {
+    my $alternative = 'to_json';
+    if (defined $_[0] and UNIVERSAL::isa($_[0], 'JSON')) {
+        shift @_; $alternative = 'encode';
+    }
+    Carp::carp "'objToJson' will be obsoleted. Please use '$alternative' instead.";
+    JSON::to_json(@_);
+};
+
+
+# INTERFACES
+
+sub to_json ($@) {
+    if (
+        ref($_[0]) eq 'JSON'
+        or (@_ > 2 and $_[0] eq 'JSON')
+    ) {
+        Carp::croak "to_json should not be called as a method.";
+    }
+    my $json = new JSON;
+
+    if (@_ == 2 and ref $_[1] eq 'HASH') {
+        my $opt  = $_[1];
+        for my $method (keys %$opt) {
+            $json->$method( $opt->{$method} );
+        }
+    }
+
+    $json->encode($_[0]);
+}
+
+
+sub from_json ($@) {
+    if ( ref($_[0]) eq 'JSON' or $_[0] eq 'JSON' ) {
+        Carp::croak "from_json should not be called as a method.";
+    }
+    my $json = new JSON;
+
+    if (@_ == 2 and ref $_[1] eq 'HASH') {
+        my $opt  = $_[1];
+        for my $method (keys %$opt) {
+            $json->$method( $opt->{$method} );
+        }
+    }
+
+    return $json->decode( $_[0] );
+}
+
+
+sub true  { $JSON::true  }
+
+sub false { $JSON::false }
+
+sub null  { undef; }
+
+
+sub require_xs_version { $XS_Version; }
+
+sub backend {
+    my $proto = shift;
+    $JSON::Backend;
+}
+
+#*module = *backend;
+
+
+sub is_xs {
+    return $_[0]->module eq $Module_XS;
+}
+
+
+sub is_pp {
+    return not $_[0]->xs;
+}
+
+
+sub pureperl_only_methods { @PPOnlyMethods; }
+
+
+sub property {
+    my ($self, $name, $value) = @_;
+
+    if (@_ == 1) {
+        my %props;
+        for $name (@Properties) {
+            my $method = 'get_' . $name;
+            if ($name eq 'max_size') {
+                my $value = $self->$method();
+                $props{$name} = $value == 1 ? 0 : $value;
+                next;
+            }
+            $props{$name} = $self->$method();
+        }
+        return \%props;
+    }
+    elsif (@_ > 3) {
+        Carp::croak('property() can take only the option within 2 arguments.');
+    }
+    elsif (@_ == 2) {
+        if ( my $method = $self->can('get_' . $name) ) {
+            if ($name eq 'max_size') {
+                my $value = $self->$method();
+                return $value == 1 ? 0 : $value;
+            }
+            $self->$method();
+        }
+    }
+    else {
+        $self->$name($value);
+    }
+
+}
+
+
+
+# INTERNAL
+
+sub _load_xs {
+    my $opt = shift;
+
+    $JSON::DEBUG and Carp::carp "Load $Module_XS.";
+
+    # if called after install module, overload is disable.... why?
+    JSON::Boolean::_overrride_overload($Module_XS);
+    JSON::Boolean::_overrride_overload($Module_PP);
+
+    eval qq|
+        use $Module_XS $XS_Version ();
+    |;
+
+    if ($@) {
+        if (defined $opt and $opt & $_INSTALL_DONT_DIE) {
+            $JSON::DEBUG and Carp::carp "Can't load $Module_XS...($@)";
+            return 0;
+        }
+        Carp::croak $@;
+    }
+
+    unless (defined $opt and $opt & $_INSTALL_ONLY) {
+        _set_module( $JSON::Backend = $Module_XS );
+        my $data = join("", <DATA>); # this code is from Jcode 2.xx.
+        close(DATA);
+        eval $data;
+        JSON::Backend::XS->init;
+    }
+
+    return 1;
+};
+
+
+sub _load_pp {
+    my $opt = shift;
+    my $backend = $_USSING_bpPP ? $Module_bp : $Module_PP;
+
+    $JSON::DEBUG and Carp::carp "Load $backend.";
+
+    # if called after install module, overload is disable.... why?
+    JSON::Boolean::_overrride_overload($Module_XS);
+    JSON::Boolean::_overrride_overload($backend);
+
+    if ( $_USSING_bpPP ) {
+        eval qq| require $backend |;
+    }
+    else {
+        eval qq| use $backend $PP_Version () |;
+    }
+
+    if ($@) {
+        if ( $backend eq $Module_PP ) {
+            $JSON::DEBUG and Carp::carp "Can't load $Module_PP ($@), so try to load $Module_bp";
+            $_USSING_bpPP++;
+            $backend = $Module_bp;
+            JSON::Boolean::_overrride_overload($backend);
+            local $^W; # if PP installed but invalid version, backportPP redifines methods.
+            eval qq| require $Module_bp |;
+        }
+        Carp::croak $@ if $@;
+    }
+
+    unless (defined $opt and $opt & $_INSTALL_ONLY) {
+        _set_module( $JSON::Backend = $Module_PP ); # even if backportPP, set $Backend with 'JSON::PP'
+        JSON::Backend::PP->init;
+    }
+};
+
+
+sub _set_module {
+    return if defined $JSON::true;
+
+    my $module = shift;
+
+    local $^W;
+    no strict qw(refs);
+
+    $JSON::true  = ${"$module\::true"};
+    $JSON::false = ${"$module\::false"};
+
+    push @JSON::ISA, $module;
+    push @{"$module\::Boolean::ISA"}, qw(JSON::Boolean);
+
+    *{"JSON::is_bool"} = \&{"$module\::is_bool"};
+
+    for my $method ($module eq $Module_XS ? @PPOnlyMethods : @XSOnlyMethods) {
+        *{"JSON::$method"} = sub {
+            Carp::carp("$method is not supported in $module.");
+            $_[0];
+        };
+    }
+
+    return 1;
+}
+
+
+
+#
+# JSON Boolean
+#
+
+package JSON::Boolean;
+
+my %Installed;
+
+sub _overrride_overload {
+    return if ($Installed{ $_[0] }++);
+
+    my $boolean = $_[0] . '::Boolean';
+
+    eval sprintf(q|
+        package %s;
+        use overload (
+            '""' => sub { ${$_[0]} == 1 ? 'true' : 'false' },
+            'eq' => sub {
+                my ($obj, $op) = ref ($_[0]) ? ($_[0], $_[1]) : ($_[1], $_[0]);
+                if ($op eq 'true' or $op eq 'false') {
+                    return "$obj" eq 'true' ? 'true' eq $op : 'false' eq $op;
+                }
+                else {
+                    return $obj ? 1 == $op : 0 == $op;
+                }
+            },
+        );
+    |, $boolean);
+
+    if ($@) { Carp::croak $@; }
+
+    return 1;
+}
+
+
+#
+# Helper classes for Backend Module (PP)
+#
+
+package JSON::Backend::PP;
+
+sub init {
+    local $^W;
+    no strict qw(refs); # this routine may be called after JSON::Backend::XS init was called.
+    *{"JSON::decode_json"} = \&{"JSON::PP::decode_json"};
+    *{"JSON::encode_json"} = \&{"JSON::PP::encode_json"};
+    *{"JSON::PP::is_xs"}  = sub { 0 };
+    *{"JSON::PP::is_pp"}  = sub { 1 };
+    return 1;
+}
+
+#
+# To save memory, the below lines are read only when XS backend is used.
+#
+
+package JSON;
+
+1;
+__DATA__
+
+
+#
+# Helper classes for Backend Module (XS)
+#
+
+package JSON::Backend::XS;
+
+use constant INDENT_LENGTH_FLAG => 15 << 12;
+
+use constant UNSUPPORTED_ENCODE_FLAG => {
+    ESCAPE_SLASH      => 0x00000010,
+    ALLOW_BIGNUM      => 0x00000020,
+    AS_NONBLESSED     => 0x00000040,
+    EXPANDED          => 0x10000000, # for developer's
+};
+
+use constant UNSUPPORTED_DECODE_FLAG => {
+    LOOSE             => 0x00000001,
+    ALLOW_BIGNUM      => 0x00000002,
+    ALLOW_BAREKEY     => 0x00000004,
+    ALLOW_SINGLEQUOTE => 0x00000008,
+    EXPANDED          => 0x20000000, # for developer's
+};
+
+
+sub init {
+    local $^W;
+    no strict qw(refs);
+    *{"JSON::decode_json"} = \&{"JSON::XS::decode_json"};
+    *{"JSON::encode_json"} = \&{"JSON::XS::encode_json"};
+    *{"JSON::XS::is_xs"}  = sub { 1 };
+    *{"JSON::XS::is_pp"}  = sub { 0 };
+    return 1;
+}
+
+
+sub support_by_pp {
+    my ($class, @methods) = @_;
+
+    local $^W;
+    no strict qw(refs);
+
+    my $JSON_XS_encode_orignal     = \&JSON::XS::encode;
+    my $JSON_XS_decode_orignal     = \&JSON::XS::decode;
+    my $JSON_XS_incr_parse_orignal = \&JSON::XS::incr_parse;
+
+    *JSON::XS::decode     = \&JSON::Backend::XS::Supportable::_decode;
+    *JSON::XS::encode     = \&JSON::Backend::XS::Supportable::_encode;
+    *JSON::XS::incr_parse = \&JSON::Backend::XS::Supportable::_incr_parse;
+
+    *{JSON::XS::_original_decode}     = $JSON_XS_decode_orignal;
+    *{JSON::XS::_original_encode}     = $JSON_XS_encode_orignal;
+    *{JSON::XS::_original_incr_parse} = $JSON_XS_incr_parse_orignal;
+
+    push @JSON::Backend::XS::Supportable::ISA, 'JSON';
+
+    my $pkg = 'JSON::Backend::XS::Supportable';
+
+    *{JSON::new} = sub {
+        my $proto = new JSON::XS; $$proto = 0;
+        bless  $proto, $pkg;
+    };
+
+
+    for my $method (@methods) {
+        my $flag = uc($method);
+        my $type |= (UNSUPPORTED_ENCODE_FLAG->{$flag} || 0);
+           $type |= (UNSUPPORTED_DECODE_FLAG->{$flag} || 0);
+
+        next unless($type);
+
+        $pkg->_make_unsupported_method($method => $type);
+    }
+
+    push @{"JSON::XS::Boolean::ISA"}, qw(JSON::PP::Boolean);
+    push @{"JSON::PP::Boolean::ISA"}, qw(JSON::Boolean);
+
+    $JSON::DEBUG and Carp::carp("set -support_by_pp mode.");
+
+    return 1;
+}
+
+
+
+
+#
+# Helper classes for XS
+#
+
+package JSON::Backend::XS::Supportable;
+
+$Carp::Internal{'JSON::Backend::XS::Supportable'} = 1;
+
+sub _make_unsupported_method {
+    my ($pkg, $method, $type) = @_;
+
+    local $^W;
+    no strict qw(refs);
+
+    *{"$pkg\::$method"} = sub {
+        local $^W;
+        if (defined $_[1] ? $_[1] : 1) {
+            ${$_[0]} |= $type;
+        }
+        else {
+            ${$_[0]} &= ~$type;
+        }
+        $_[0];
+    };
+
+    *{"$pkg\::get_$method"} = sub {
+        ${$_[0]} & $type ? 1 : '';
+    };
+
+}
+
+
+sub _set_for_pp {
+    JSON::_load_pp( $_INSTALL_ONLY );
+
+    my $type  = shift;
+    my $pp    = new JSON::PP;
+    my $prop = $_[0]->property;
+
+    for my $name (keys %$prop) {
+        $pp->$name( $prop->{$name} ? $prop->{$name} : 0 );
+    }
+
+    my $unsupported = $type eq 'encode' ? JSON::Backend::XS::UNSUPPORTED_ENCODE_FLAG
+                                        : JSON::Backend::XS::UNSUPPORTED_DECODE_FLAG;
+    my $flags       = ${$_[0]} || 0;
+
+    for my $name (keys %$unsupported) {
+        next if ($name eq 'EXPANDED'); # for developer's
+        my $enable = ($flags & $unsupported->{$name}) ? 1 : 0;
+        my $method = lc $name;
+        $pp->$method($enable);
+    }
+
+    $pp->indent_length( $_[0]->get_indent_length );
+
+    return $pp;
+}
+
+sub _encode { # using with PP encod
+    if (${$_[0]}) {
+        _set_for_pp('encode' => @_)->encode($_[1]);
+    }
+    else {
+        $_[0]->_original_encode( $_[1] );
+    }
+}
+
+
+sub _decode { # if unsupported-flag is set, use PP
+    if (${$_[0]}) {
+        _set_for_pp('decode' => @_)->decode($_[1]);
+    }
+    else {
+        $_[0]->_original_decode( $_[1] );
+    }
+}
+
+
+sub decode_prefix { # if unsupported-flag is set, use PP
+    _set_for_pp('decode' => @_)->decode_prefix($_[1]);
+}
+
+
+sub _incr_parse {
+    if (${$_[0]}) {
+        _set_for_pp('decode' => @_)->incr_parse($_[1]);
+    }
+    else {
+        $_[0]->_original_incr_parse( $_[1] );
+    }
+}
+
+
+sub get_indent_length {
+    ${$_[0]} << 4 >> 16;
+}
+
+
+sub indent_length {
+    my $length = $_[1];
+
+    if (!defined $length or $length > 15 or $length < 0) {
+        Carp::carp "The acceptable range of indent_length() is 0 to 15.";
+    }
+    else {
+        local $^W;
+        $length <<= 12;
+        ${$_[0]} &= ~ JSON::Backend::XS::INDENT_LENGTH_FLAG;
+        ${$_[0]} |= $length;
+        *JSON::XS::encode = \&JSON::Backend::XS::Supportable::_encode;
+    }
+
+    $_[0];
+}
+
+
+1;
+__END__
+
+=head1 NAME
+
+JSON - JSON (JavaScript Object Notation) encoder/decoder
+
+=head1 SYNOPSIS
+
+ use JSON; # imports encode_json, decode_json, to_json and from_json.
+
+ # simple and fast interfaces (expect/generate UTF-8)
+
+ $utf8_encoded_json_text = encode_json $perl_hash_or_arrayref;
+ $perl_hash_or_arrayref  = decode_json $utf8_encoded_json_text;
+
+ # OO-interface
+
+ $json = JSON->new->allow_nonref;
+
+ $json_text   = $json->encode( $perl_scalar );
+ $perl_scalar = $json->decode( $json_text );
+
+ $pretty_printed = $json->pretty->encode( $perl_scalar ); # pretty-printing
+
+ # If you want to use PP only support features, call with '-support_by_pp'
+ # When XS unsupported feature is enable, using PP (de|en)code instead of XS ones.
+
+ use JSON -support_by_pp;
+
+ # option-acceptable interfaces (expect/generate UNICODE by default)
+
+ $json_text   = to_json( $perl_scalar, { ascii => 1, pretty => 1 } );
+ $perl_scalar = from_json( $json_text, { utf8  => 1 } );
+
+ # Between (en|de)code_json and (to|from)_json, if you want to write
+ # a code which communicates to an outer world (encoded in UTF-8),
+ # recommend to use (en|de)code_json.
+
+=head1 VERSION
+
+    2.53
+
+This version is compatible with JSON::XS B<2.27> and later.
+
+
+=head1 NOTE
+
+JSON::PP was inculded in C<JSON> distribution.
+It comes to be a perl core module in Perl 5.14.
+And L<JSON::PP> will be split away it.
+
+C<JSON> distribution will inculde yet another JSON::PP modules.
+They are JSNO::backportPP and so on. JSON.pm should work as it did at all.
+
+=head1 DESCRIPTION
+
+ ************************** CAUTION ********************************
+ * This is 'JSON module version 2' and there are many differences  *
+ * to version 1.xx                                                 *
+ * Please check your applications useing old version.              *
+ *   See to 'INCOMPATIBLE CHANGES TO OLD VERSION'                  *
+ *******************************************************************
+
+JSON (JavaScript Object Notation) is a simple data format.
+See to L<http://www.json.org/> and C<RFC4627>(L<http://www.ietf.org/rfc/rfc4627.txt>).
+
+This module converts Perl data structures to JSON and vice versa using either
+L<JSON::XS> or L<JSON::PP>.
+
+JSON::XS is the fastest and most proper JSON module on CPAN which must be
+compiled and installed in your environment.
+JSON::PP is a pure-Perl module which is bundled in this distribution and
+has a strong compatibility to JSON::XS.
+
+This module try to use JSON::XS by default and fail to it, use JSON::PP instead.
+So its features completely depend on JSON::XS or JSON::PP.
+
+See to L<BACKEND MODULE DECISION>.
+
+To distinguish the module name 'JSON' and the format type JSON,
+the former is quoted by CE<lt>E<gt> (its results vary with your using media),
+and the latter is left just as it is.
+
+Module name : C<JSON>
+
+Format type : JSON
+
+=head2 FEATURES
+
+=over
+
+=item * correct unicode handling
+
+This module (i.e. backend modules) knows how to handle Unicode, documents
+how and when it does so, and even documents what "correct" means.
+
+Even though there are limitations, this feature is available since Perl version 5.6.
+
+JSON::XS requires Perl 5.8.2 (but works correctly in 5.8.8 or later), so in older versions
+C<JSON> sholud call JSON::PP as the backend which can be used since Perl 5.005.
+
+With Perl 5.8.x JSON::PP works, but from 5.8.0 to 5.8.2, because of a Perl side problem,
+JSON::PP works slower in the versions. And in 5.005, the Unicode handling is not available.
+See to L<JSON::PP/UNICODE HANDLING ON PERLS> for more information.
+
+See also to L<JSON::XS/A FEW NOTES ON UNICODE AND PERL>
+and L<JSON::XS/ENCODING/CODESET_FLAG_NOTES>.
+
+
+=item * round-trip integrity
+
+When you serialise a perl data structure using only data types supported
+by JSON and Perl, the deserialised data structure is identical on the Perl
+level. (e.g. the string "2.0" doesn't suddenly become "2" just because
+it looks like a number). There I<are> minor exceptions to this, read the
+L</MAPPING> section below to learn about those.
+
+
+=item * strict checking of JSON correctness
+
+There is no guessing, no generating of illegal JSON texts by default,
+and only JSON is accepted as input by default (the latter is a security
+feature).
+
+See to L<JSON::XS/FEATURES> and L<JSON::PP/FEATURES>.
+
+=item * fast
+
+This module returns a JSON::XS object itself if available.
+Compared to other JSON modules and other serialisers such as Storable,
+JSON::XS usually compares favourably in terms of speed, too.
+
+If not available, C<JSON> returns a JSON::PP object instead of JSON::XS and
+it is very slow as pure-Perl.
+
+=item * simple to use
+
+This module has both a simple functional interface as well as an
+object oriented interface interface.
+
+=item * reasonably versatile output formats
+
+You can choose between the most compact guaranteed-single-line format possible
+(nice for simple line-based protocols), a pure-ASCII format (for when your transport
+is not 8-bit clean, still supports the whole Unicode range), or a pretty-printed
+format (for when you want to read that stuff). Or you can combine those features
+in whatever way you like.
+
+=back
+
+=head1 FUNCTIONAL INTERFACE
+
+Some documents are copied and modified from L<JSON::XS/FUNCTIONAL INTERFACE>.
+C<to_json> and C<from_json> are additional functions.
+
+=head2 encode_json
+
+    $json_text = encode_json $perl_scalar
+
+Converts the given Perl data structure to a UTF-8 encoded, binary string.
+
+This function call is functionally identical to:
+
+    $json_text = JSON->new->utf8->encode($perl_scalar)
+
+=head2 decode_json
+
+    $perl_scalar = decode_json $json_text
+
+The opposite of C<encode_json>: expects an UTF-8 (binary) string and tries
+to parse that as an UTF-8 encoded JSON text, returning the resulting
+reference.
+
+This function call is functionally identical to:
+
+    $perl_scalar = JSON->new->utf8->decode($json_text)
+
+
+=head2 to_json
+
+   $json_text = to_json($perl_scalar)
+
+Converts the given Perl data structure to a json string.
+
+This function call is functionally identical to:
+
+   $json_text = JSON->new->encode($perl_scalar)
+
+Takes a hash reference as the second.
+
+   $json_text = to_json($perl_scalar, $flag_hashref)
+
+So,
+
+   $json_text = to_json($perl_scalar, {utf8 => 1, pretty => 1})
+
+equivalent to:
+
+   $json_text = JSON->new->utf8(1)->pretty(1)->encode($perl_scalar)
+
+If you want to write a modern perl code which communicates to outer world,
+you should use C<encode_json> (supposed that JSON data are encoded in UTF-8).
+
+=head2 from_json
+
+   $perl_scalar = from_json($json_text)
+
+The opposite of C<to_json>: expects a json string and tries
+to parse it, returning the resulting reference.
+
+This function call is functionally identical to:
+
+    $perl_scalar = JSON->decode($json_text)
+
+Takes a hash reference as the second.
+
+    $perl_scalar = from_json($json_text, $flag_hashref)
+
+So,
+
+    $perl_scalar = from_json($json_text, {utf8 => 1})
+
+equivalent to:
+
+    $perl_scalar = JSON->new->utf8(1)->decode($json_text)
+
+If you want to write a modern perl code which communicates to outer world,
+you should use C<decode_json> (supposed that JSON data are encoded in UTF-8).
+
+=head2 JSON::is_bool
+
+    $is_boolean = JSON::is_bool($scalar)
+
+Returns true if the passed scalar represents either JSON::true or
+JSON::false, two constants that act like C<1> and C<0> respectively
+and are also used to represent JSON C<true> and C<false> in Perl strings.
+
+=head2 JSON::true
+
+Returns JSON true value which is blessed object.
+It C<isa> JSON::Boolean object.
+
+=head2 JSON::false
+
+Returns JSON false value which is blessed object.
+It C<isa> JSON::Boolean object.
+
+=head2 JSON::null
+
+Returns C<undef>.
+
+See L<MAPPING>, below, for more information on how JSON values are mapped to
+Perl.
+
+=head1 HOW DO I DECODE A DATA FROM OUTER AND ENCODE TO OUTER
+
+This section supposes that your perl vresion is 5.8 or later.
+
+If you know a JSON text from an outer world - a network, a file content, and so on,
+is encoded in UTF-8, you should use C<decode_json> or C<JSON> module object
+with C<utf8> enable. And the decoded result will contain UNICODE characters.
+
+  # from network
+  my $json        = JSON->new->utf8;
+  my $json_text   = CGI->new->param( 'json_data' );
+  my $perl_scalar = $json->decode( $json_text );
+
+  # from file content
+  local $/;
+  open( my $fh, '<', 'json.data' );
+  $json_text   = <$fh>;
+  $perl_scalar = decode_json( $json_text );
+
+If an outer data is not encoded in UTF-8, firstly you should C<decode> it.
+
+  use Encode;
+  local $/;
+  open( my $fh, '<', 'json.data' );
+  my $encoding = 'cp932';
+  my $unicode_json_text = decode( $encoding, <$fh> ); # UNICODE
+
+  # or you can write the below code.
+  #
+  # open( my $fh, "<:encoding($encoding)", 'json.data' );
+  # $unicode_json_text = <$fh>;
+
+In this case, C<$unicode_json_text> is of course UNICODE string.
+So you B<cannot> use C<decode_json> nor C<JSON> module object with C<utf8> enable.
+Instead of them, you use C<JSON> module object with C<utf8> disable or C<from_json>.
+
+  $perl_scalar = $json->utf8(0)->decode( $unicode_json_text );
+  # or
+  $perl_scalar = from_json( $unicode_json_text );
+
+Or C<encode 'utf8'> and C<decode_json>:
+
+  $perl_scalar = decode_json( encode( 'utf8', $unicode_json_text ) );
+  # this way is not efficient.
+
+And now, you want to convert your C<$perl_scalar> into JSON data and
+send it to an outer world - a network or a file content, and so on.
+
+Your data usually contains UNICODE strings and you want the converted data to be encoded
+in UTF-8, you should use C<encode_json> or C<JSON> module object with C<utf8> enable.
+
+  print encode_json( $perl_scalar ); # to a network? file? or display?
+  # or
+  print $json->utf8->encode( $perl_scalar );
+
+If C<$perl_scalar> does not contain UNICODE but C<$encoding>-encoded strings
+for some reason, then its characters are regarded as B<latin1> for perl
+(because it does not concern with your $encoding).
+You B<cannot> use C<encode_json> nor C<JSON> module object with C<utf8> enable.
+Instead of them, you use C<JSON> module object with C<utf8> disable or C<to_json>.
+Note that the resulted text is a UNICODE string but no problem to print it.
+
+  # $perl_scalar contains $encoding encoded string values
+  $unicode_json_text = $json->utf8(0)->encode( $perl_scalar );
+  # or
+  $unicode_json_text = to_json( $perl_scalar );
+  # $unicode_json_text consists of characters less than 0x100
+  print $unicode_json_text;
+
+Or C<decode $encoding> all string values and C<encode_json>:
+
+  $perl_scalar->{ foo } = decode( $encoding, $perl_scalar->{ foo } );
+  # ... do it to each string values, then encode_json
+  $json_text = encode_json( $perl_scalar );
+
+This method is a proper way but probably not efficient.
+
+See to L<Encode>, L<perluniintro>.
+
+
+=head1 COMMON OBJECT-ORIENTED INTERFACE
+
+=head2 new
+
+    $json = new JSON
+
+Returns a new C<JSON> object inherited from either JSON::XS or JSON::PP
+that can be used to de/encode JSON strings.
+
+All boolean flags described below are by default I<disabled>.
+
+The mutators for flags all return the JSON object again and thus calls can
+be chained:
+
+   my $json = JSON->new->utf8->space_after->encode({a => [1,2]})
+   => {"a": [1, 2]}
+
+=head2 ascii
+
+    $json = $json->ascii([$enable])
+
+    $enabled = $json->get_ascii
+
+If $enable is true (or missing), then the encode method will not generate characters outside
+the code range 0..127. Any Unicode characters outside that range will be escaped using either
+a single \uXXXX or a double \uHHHH\uLLLLL escape sequence, as per RFC4627.
+
+If $enable is false, then the encode method will not escape Unicode characters unless
+required by the JSON syntax or other flags. This results in a faster and more compact format.
+
+This feature depends on the used Perl version and environment.
+
+See to L<JSON::PP/UNICODE HANDLING ON PERLS> if the backend is PP.
+
+  JSON->new->ascii(1)->encode([chr 0x10401])
+  => ["\ud801\udc01"]
+
+=head2 latin1
+
+    $json = $json->latin1([$enable])
+
+    $enabled = $json->get_latin1
+
+If $enable is true (or missing), then the encode method will encode the resulting JSON
+text as latin1 (or iso-8859-1), escaping any characters outside the code range 0..255.
+
+If $enable is false, then the encode method will not escape Unicode characters
+unless required by the JSON syntax or other flags.
+
+  JSON->new->latin1->encode (["\x{89}\x{abc}"]
+  => ["\x{89}\\u0abc"]    # (perl syntax, U+abc escaped, U+89 not)
+
+=head2 utf8
+
+    $json = $json->utf8([$enable])
+
+    $enabled = $json->get_utf8
+
+If $enable is true (or missing), then the encode method will encode the JSON result
+into UTF-8, as required by many protocols, while the decode method expects to be handled
+an UTF-8-encoded string. Please note that UTF-8-encoded strings do not contain any
+characters outside the range 0..255, they are thus useful for bytewise/binary I/O.
+
+In future versions, enabling this option might enable autodetection of the UTF-16 and UTF-32
+encoding families, as described in RFC4627.
+
+If $enable is false, then the encode method will return the JSON string as a (non-encoded)
+Unicode string, while decode expects thus a Unicode string. Any decoding or encoding
+(e.g. to UTF-8 or UTF-16) needs to be done yourself, e.g. using the Encode module.
+
+
+Example, output UTF-16BE-encoded JSON:
+
+  use Encode;
+  $jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
+
+Example, decode UTF-32LE-encoded JSON:
+
+  use Encode;
+  $object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
+
+See to L<JSON::PP/UNICODE HANDLING ON PERLS> if the backend is PP.
+
+
+=head2 pretty
+
+    $json = $json->pretty([$enable])
+
+This enables (or disables) all of the C<indent>, C<space_before> and
+C<space_after> (and in the future possibly more) flags in one call to
+generate the most readable (or most compact) form possible.
+
+Equivalent to:
+
+   $json->indent->space_before->space_after
+
+The indent space length is three and JSON::XS cannot change the indent
+space length.
+
+=head2 indent
+
+    $json = $json->indent([$enable])
+
+    $enabled = $json->get_indent
+
+If C<$enable> is true (or missing), then the C<encode> method will use a multiline
+format as output, putting every array member or object/hash key-value pair
+into its own line, identing them properly.
+
+If C<$enable> is false, no newlines or indenting will be produced, and the
+resulting JSON text is guarenteed not to contain any C<newlines>.
+
+This setting has no effect when decoding JSON texts.
+
+The indent space length is three.
+With JSON::PP, you can also access C<indent_length> to change indent space length.
+
+
+=head2 space_before
+
+    $json = $json->space_before([$enable])
+
+    $enabled = $json->get_space_before
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space before the C<:> separating keys from values in JSON objects.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts.
+
+Example, space_before enabled, space_after and indent disabled:
+
+   {"key" :"value"}
+
+
+=head2 space_after
+
+    $json = $json->space_after([$enable])
+
+    $enabled = $json->get_space_after
+
+If C<$enable> is true (or missing), then the C<encode> method will add an extra
+optional space after the C<:> separating keys from values in JSON objects
+and extra whitespace after the C<,> separating key-value pairs and array
+members.
+
+If C<$enable> is false, then the C<encode> method will not add any extra
+space at those places.
+
+This setting has no effect when decoding JSON texts.
+
+Example, space_before and indent disabled, space_after enabled:
+
+   {"key": "value"}
+
+
+=head2 relaxed
+
+    $json = $json->relaxed([$enable])
+
+    $enabled = $json->get_relaxed
+
+If C<$enable> is true (or missing), then C<decode> will accept some
+extensions to normal JSON syntax (see below). C<encode> will not be
+affected in anyway. I<Be aware that this option makes you accept invalid
+JSON texts as if they were valid!>. I suggest only to use this option to
+parse application-specific files written by humans (configuration files,
+resource files etc.)
+
+If C<$enable> is false (the default), then C<decode> will only accept
+valid JSON texts.
+
+Currently accepted extensions are:
+
+=over 4
+
+=item * list items can have an end-comma
+
+JSON I<separates> array elements and key-value pairs with commas. This
+can be annoying if you write JSON texts manually and want to be able to
+quickly append elements, so this extension accepts comma at the end of
+such items not just between them:
+
+   [
+      1,
+      2, <- this comma not normally allowed
+   ]
+   {
+      "k1": "v1",
+      "k2": "v2", <- this comma not normally allowed
+   }
+
+=item * shell-style '#'-comments
+
+Whenever JSON allows whitespace, shell-style comments are additionally
+allowed. They are terminated by the first carriage-return or line-feed
+character, after which more white-space and comments are allowed.
+
+  [
+     1, # this comment not allowed in JSON
+        # neither this one...
+  ]
+
+=back
+
+
+=head2 canonical
+
+    $json = $json->canonical([$enable])
+
+    $enabled = $json->get_canonical
+
+If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
+by sorting their keys. This is adding a comparatively high overhead.
+
+If C<$enable> is false, then the C<encode> method will output key-value
+pairs in the order Perl stores them (which will likely change between runs
+of the same script).
+
+This option is useful if you want the same data structure to be encoded as
+the same JSON text (given the same overall settings). If it is disabled,
+the same hash might be encoded differently even if contains the same data,
+as key-value pairs have no inherent ordering in Perl.
+
+This setting has no effect when decoding JSON texts.
+
+=head2 allow_nonref
+
+    $json = $json->allow_nonref([$enable])
+
+    $enabled = $json->get_allow_nonref
+
+If C<$enable> is true (or missing), then the C<encode> method can convert a
+non-reference into its corresponding string, number or null JSON value,
+which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
+values instead of croaking.
+
+If C<$enable> is false, then the C<encode> method will croak if it isn't
+passed an arrayref or hashref, as JSON texts must either be an object
+or array. Likewise, C<decode> will croak if given something that is not a
+JSON object or array.
+
+   JSON->new->allow_nonref->encode ("Hello, World!")
+   => "Hello, World!"
+
+=head2 allow_unknown
+
+    $json = $json->allow_unknown ([$enable])
+
+    $enabled = $json->get_allow_unknown
+
+If $enable is true (or missing), then "encode" will *not* throw an
+exception when it encounters values it cannot represent in JSON (for
+example, filehandles) but instead will encode a JSON "null" value.
+Note that blessed objects are not included here and are handled
+separately by c<allow_nonref>.
+
+If $enable is false (the default), then "encode" will throw an
+exception when it encounters anything it cannot encode as JSON.
+
+This option does not affect "decode" in any way, and it is
+recommended to leave it off unless you know your communications
+partner.
+
+=head2 allow_blessed
+
+    $json = $json->allow_blessed([$enable])
+
+    $enabled = $json->get_allow_blessed
+
+If C<$enable> is true (or missing), then the C<encode> method will not
+barf when it encounters a blessed reference. Instead, the value of the
+B<convert_blessed> option will decide whether C<null> (C<convert_blessed>
+disabled or no C<TO_JSON> method found) or a representation of the
+object (C<convert_blessed> enabled and C<TO_JSON> method found) is being
+encoded. Has no effect on C<decode>.
+
+If C<$enable> is false (the default), then C<encode> will throw an
+exception when it encounters a blessed object.
+
+
+=head2 convert_blessed
+
+    $json = $json->convert_blessed([$enable])
+
+    $enabled = $json->get_convert_blessed
+
+If C<$enable> is true (or missing), then C<encode>, upon encountering a
+blessed object, will check for the availability of the C<TO_JSON> method
+on the object's class. If found, it will be called in scalar context
+and the resulting scalar will be encoded instead of the object. If no
+C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
+to do.
+
+The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
+returns other blessed objects, those will be handled in the same
+way. C<TO_JSON> must take care of not causing an endless recursion cycle
+(== crash) in this case. The name of C<TO_JSON> was chosen because other
+methods called by the Perl core (== not by the user of the object) are
+usually in upper case letters and to avoid collisions with the C<to_json>
+function or method.
+
+This setting does not yet influence C<decode> in any way.
+
+If C<$enable> is false, then the C<allow_blessed> setting will decide what
+to do when a blessed object is found.
+
+=over
+
+=item convert_blessed_universally mode
+
+If use C<JSON> with C<-convert_blessed_universally>, the C<UNIVERSAL::TO_JSON>
+subroutine is defined as the below code:
+
+   *UNIVERSAL::TO_JSON = sub {
+       my $b_obj = B::svref_2object( $_[0] );
+       return    $b_obj->isa('B::HV') ? { %{ $_[0] } }
+               : $b_obj->isa('B::AV') ? [ @{ $_[0] } ]
+               : undef
+               ;
+   }
+
+This will cause that C<encode> method converts simple blessed objects into
+JSON objects as non-blessed object.
+
+   JSON -convert_blessed_universally;
+   $json->allow_blessed->convert_blessed->encode( $blessed_object )
+
+This feature is experimental and may be removed in the future.
+
+=back
+
+=head2 filter_json_object
+
+    $json = $json->filter_json_object([$coderef])
+
+When C<$coderef> is specified, it will be called from C<decode> each
+time it decodes a JSON object. The only argument passed to the coderef
+is a reference to the newly-created hash. If the code references returns
+a single scalar (which need not be a reference), this value
+(i.e. a copy of that scalar to avoid aliasing) is inserted into the
+deserialised data structure. If it returns an empty list
+(NOTE: I<not> C<undef>, which is a valid scalar), the original deserialised
+hash will be inserted. This setting can slow down decoding considerably.
+
+When C<$coderef> is omitted or undefined, any existing callback will
+be removed and C<decode> will not change the deserialised hash in any
+way.
+
+Example, convert all JSON objects into the integer 5:
+
+   my $js = JSON->new->filter_json_object (sub { 5 });
+   # returns [5]
+   $js->decode ('[{}]'); # the given subroutine takes a hash reference.
+   # throw an exception because allow_nonref is not enabled
+   # so a lone 5 is not allowed.
+   $js->decode ('{"a":1, "b":2}');
+
+
+=head2 filter_json_single_key_object
+
+    $json = $json->filter_json_single_key_object($key [=> $coderef])
+
+Works remotely similar to C<filter_json_object>, but is only called for
+JSON objects having a single key named C<$key>.
+
+This C<$coderef> is called before the one specified via
+C<filter_json_object>, if any. It gets passed the single value in the JSON
+object. If it returns a single value, it will be inserted into the data
+structure. If it returns nothing (not even C<undef> but the empty list),
+the callback from C<filter_json_object> will be called next, as if no
+single-key callback were specified.
+
+If C<$coderef> is omitted or undefined, the corresponding callback will be
+disabled. There can only ever be one callback for a given key.
+
+As this callback gets called less often then the C<filter_json_object>
+one, decoding speed will not usually suffer as much. Therefore, single-key
+objects make excellent targets to serialise Perl objects into, especially
+as single-key JSON objects are as close to the type-tagged value concept
+as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON does not
+support this in any way, so you need to make sure your data never looks
+like a serialised Perl hash.
+
+Typical names for the single object key are C<__class_whatever__>, or
+C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
+things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
+with real hashes.
+
+Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
+into the corresponding C<< $WIDGET{<id>} >> object:
+
+   # return whatever is in $WIDGET{5}:
+   JSON
+      ->new
+      ->filter_json_single_key_object (__widget__ => sub {
+            $WIDGET{ $_[0] }
+         })
+      ->decode ('{"__widget__": 5')
+
+   # this can be used with a TO_JSON method in some "widget" class
+   # for serialisation to json:
+   sub WidgetBase::TO_JSON {
+      my ($self) = @_;
+
+      unless ($self->{id}) {
+         $self->{id} = ..get..some..id..;
+         $WIDGET{$self->{id}} = $self;
+      }
+
+      { __widget__ => $self->{id} }
+   }
+
+
+=head2 shrink
+
+    $json = $json->shrink([$enable])
+
+    $enabled = $json->get_shrink
+
+With JSON::XS, this flag resizes strings generated by either
+C<encode> or C<decode> to their minimum size possible. This can save
+memory when your JSON texts are either very very long or you have many
+short strings. It will also try to downgrade any strings to octet-form
+if possible: perl stores strings internally either in an encoding called
+UTF-X or in octet-form. The latter cannot store everything but uses less
+space in general (and some buggy Perl or C code might even rely on that
+internal representation being used).
+
+With JSON::PP, it is noop about resizing strings but tries
+C<utf8::downgrade> to the returned string by C<encode>. See to L<utf8>.
+
+See to L<JSON::XS/OBJECT-ORIENTED INTERFACE> and L<JSON::PP/METHODS>.
+
+=head2 max_depth
+
+    $json = $json->max_depth([$maximum_nesting_depth])
+
+    $max_depth = $json->get_max_depth
+
+Sets the maximum nesting level (default C<512>) accepted while encoding
+or decoding. If a higher nesting level is detected in JSON text or a Perl
+data structure, then the encoder and decoder will stop and croak at that
+point.
+
+Nesting level is defined by number of hash- or arrayrefs that the encoder
+needs to traverse to reach a given point or the number of C<{> or C<[>
+characters without their matching closing parenthesis crossed to reach a
+given character in a string.
+
+If no argument is given, the highest possible setting will be used, which
+is rarely useful.
+
+Note that nesting is implemented by recursion in C. The default value has
+been chosen to be as large as typical operating systems allow without
+crashing. (JSON::XS)
+
+With JSON::PP as the backend, when a large value (100 or more) was set and
+it de/encodes a deep nested object/text, it may raise a warning
+'Deep recursion on subroutin' at the perl runtime phase.
+
+See L<JSON::XS/SECURITY CONSIDERATIONS> for more info on why this is useful.
+
+=head2 max_size
+
+    $json = $json->max_size([$maximum_string_size])
+
+    $max_size = $json->get_max_size
+
+Set the maximum length a JSON text may have (in bytes) where decoding is
+being attempted. The default is C<0>, meaning no limit. When C<decode>
+is called on a string that is longer then this many bytes, it will not
+attempt to decode the string but throw an exception. This setting has no
+effect on C<encode> (yet).
+
+If no argument is given, the limit check will be deactivated (same as when
+C<0> is specified).
+
+See L<JSON::XS/SECURITY CONSIDERATIONS>, below, for more info on why this is useful.
+
+=head2 encode
+
+    $json_text = $json->encode($perl_scalar)
+
+Converts the given Perl data structure (a simple scalar or a reference
+to a hash or array) to its JSON representation. Simple scalars will be
+converted into JSON string or number sequences, while references to arrays
+become JSON arrays and references to hashes become JSON objects. Undefined
+Perl values (e.g. C<undef>) become JSON C<null> values.
+References to the integers C<0> and C<1> are converted into C<true> and C<false>.
+
+=head2 decode
+
+    $perl_scalar = $json->decode($json_text)
+
+The opposite of C<encode>: expects a JSON text and tries to parse it,
+returning the resulting simple scalar or reference. Croaks on error.
+
+JSON numbers and strings become simple Perl scalars. JSON arrays become
+Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
+C<1> (C<JSON::true>), C<false> becomes C<0> (C<JSON::false>) and
+C<null> becomes C<undef>.
+
+=head2 decode_prefix
+
+    ($perl_scalar, $characters) = $json->decode_prefix($json_text)
+
+This works like the C<decode> method, but instead of raising an exception
+when there is trailing garbage after the first JSON object, it will
+silently stop parsing there and return the number of characters consumed
+so far.
+
+   JSON->new->decode_prefix ("[1] the tail")
+   => ([], 3)
+
+See to L<JSON::XS/OBJECT-ORIENTED INTERFACE>
+
+=head2 property
+
+    $boolean = $json->property($property_name)
+
+Returns a boolean value about above some properties.
+
+The available properties are C<ascii>, C<latin1>, C<utf8>,
+C<indent>,C<space_before>, C<space_after>, C<relaxed>, C<canonical>,
+C<allow_nonref>, C<allow_unknown>, C<allow_blessed>, C<convert_blessed>,
+C<shrink>, C<max_depth> and C<max_size>.
+
+   $boolean = $json->property('utf8');
+    => 0
+   $json->utf8;
+   $boolean = $json->property('utf8');
+    => 1
+
+Sets the property with a given boolean value.
+
+    $json = $json->property($property_name => $boolean);
+
+With no argumnt, it returns all the above properties as a hash reference.
+
+    $flag_hashref = $json->property();
+
+=head1 INCREMENTAL PARSING
+
+Most of this section are copied and modified from L<JSON::XS/INCREMENTAL PARSING>.
+
+In some cases, there is the need for incremental parsing of JSON texts.
+This module does allow you to parse a JSON stream incrementally.
+It does so by accumulating text until it has a full JSON object, which
+it then can decode. This process is similar to using C<decode_prefix>
+to see if a full JSON object is available, but is much more efficient
+(and can be implemented with a minimum of method calls).
+
+The backend module will only attempt to parse the JSON text once it is sure it
+has enough text to get a decisive result, using a very simple but
+truly incremental parser. This means that it sometimes won't stop as
+early as the full parser, for example, it doesn't detect parenthese
+mismatches. The only thing it guarantees is that it starts decoding as
+soon as a syntactically valid JSON text has been seen. This means you need
+to set resource limits (e.g. C<max_size>) to ensure the parser will stop
+parsing in the presence if syntax errors.
+
+The following methods implement this incremental parser.
+
+=head2 incr_parse
+
+    $json->incr_parse( [$string] ) # void context
+
+    $obj_or_undef = $json->incr_parse( [$string] ) # scalar context
+
+    @obj_or_empty = $json->incr_parse( [$string] ) # list context
+
+This is the central parsing function. It can both append new text and
+extract objects from the stream accumulated so far (both of these
+functions are optional).
+
+If C<$string> is given, then this string is appended to the already
+existing JSON fragment stored in the C<$json> object.
+
+After that, if the function is called in void context, it will simply
+return without doing anything further. This can be used to add more text
+in as many chunks as you want.
+
+If the method is called in scalar context, then it will try to extract
+exactly I<one> JSON object. If that is successful, it will return this
+object, otherwise it will return C<undef>. If there is a parse error,
+this method will croak just as C<decode> would do (one can then use
+C<incr_skip> to skip the errornous part). This is the most common way of
+using the method.
+
+And finally, in list context, it will try to extract as many objects
+from the stream as it can find and return them, or the empty list
+otherwise. For this to work, there must be no separators between the JSON
+objects or arrays, instead they must be concatenated back-to-back. If
+an error occurs, an exception will be raised as in the scalar context
+case. Note that in this case, any previously-parsed JSON texts will be
+lost.
+
+Example: Parse some JSON arrays/objects in a given string and return them.
+
+    my @objs = JSON->new->incr_parse ("[5][7][1,2]");
+
+=head2 incr_text
+
+    $lvalue_string = $json->incr_text
+
+This method returns the currently stored JSON fragment as an lvalue, that
+is, you can manipulate it. This I<only> works when a preceding call to
+C<incr_parse> in I<scalar context> successfully returned an object. Under
+all other circumstances you must not call this function (I mean it.
+although in simple tests it might actually work, it I<will> fail under
+real world conditions). As a special exception, you can also call this
+method before having parsed anything.
+
+This function is useful in two cases: a) finding the trailing text after a
+JSON object or b) parsing multiple JSON objects separated by non-JSON text
+(such as commas).
+
+    $json->incr_text =~ s/\s*,\s*//;
+
+In Perl 5.005, C<lvalue> attribute is not available.
+You must write codes like the below:
+
+    $string = $json->incr_text;
+    $string =~ s/\s*,\s*//;
+    $json->incr_text( $string );
+
+=head2 incr_skip
+
+    $json->incr_skip
+
+This will reset the state of the incremental parser and will remove the
+parsed text from the input buffer. This is useful after C<incr_parse>
+died, in which case the input buffer and incremental parser state is left
+unchanged, to skip the text parsed so far and to reset the parse state.
+
+=head2 incr_reset
+
+    $json->incr_reset
+
+This completely resets the incremental parser, that is, after this call,
+it will be as if the parser had never parsed anything.
+
+This is useful if you want ot repeatedly parse JSON objects and want to
+ignore any trailing data, which means you have to reset the parser after
+each successful decode.
+
+See to L<JSON::XS/INCREMENTAL PARSING> for examples.
+
+
+=head1 JSON::PP SUPPORT METHODS
+
+The below methods are JSON::PP own methods, so when C<JSON> works
+with JSON::PP (i.e. the created object is a JSON::PP object), available.
+See to L<JSON::PP/JSON::PP OWN METHODS> in detail.
+
+If you use C<JSON> with additonal C<-support_by_pp>, some methods
+are available even with JSON::XS. See to L<USE PP FEATURES EVEN THOUGH XS BACKEND>.
+
+   BEING { $ENV{PERL_JSON_BACKEND} = 'JSON::XS' }
+
+   use JSON -support_by_pp;
+
+   my $json = new JSON;
+   $json->allow_nonref->escape_slash->encode("/");
+
+   # functional interfaces too.
+   print to_json(["/"], {escape_slash => 1});
+   print from_json('["foo"]', {utf8 => 1});
+
+If you do not want to all functions but C<-support_by_pp>,
+use C<-no_export>.
+
+   use JSON -support_by_pp, -no_export;
+   # functional interfaces are not exported.
+
+=head2 allow_singlequote
+
+    $json = $json->allow_singlequote([$enable])
+
+If C<$enable> is true (or missing), then C<decode> will accept
+any JSON strings quoted by single quotations that are invalid JSON
+format.
+
+    $json->allow_singlequote->decode({"foo":'bar'});
+    $json->allow_singlequote->decode({'foo':"bar"});
+    $json->allow_singlequote->decode({'foo':'bar'});
+
+As same as the C<relaxed> option, this option may be used to parse
+application-specific files written by humans.
+
+=head2 allow_barekey
+
+    $json = $json->allow_barekey([$enable])
+
+If C<$enable> is true (or missing), then C<decode> will accept
+bare keys of JSON object that are invalid JSON format.
+
+As same as the C<relaxed> option, this option may be used to parse
+application-specific files written by humans.
+
+    $json->allow_barekey->decode('{foo:"bar"}');
+
+=head2 allow_bignum
+
+    $json = $json->allow_bignum([$enable])
+
+If C<$enable> is true (or missing), then C<decode> will convert
+the big integer Perl cannot handle as integer into a L<Math::BigInt>
+object and convert a floating number (any) into a L<Math::BigFloat>.
+
+On the contary, C<encode> converts C<Math::BigInt> objects and C<Math::BigFloat>
+objects into JSON numbers with C<allow_blessed> enable.
+
+   $json->allow_nonref->allow_blessed->allow_bignum;
+   $bigfloat = $json->decode('2.000000000000000000000000001');
+   print $json->encode($bigfloat);
+   # => 2.000000000000000000000000001
+
+See to L<MAPPING> aboout the conversion of JSON number.
+
+=head2 loose
+
+    $json = $json->loose([$enable])
+
+The unescaped [\x00-\x1f\x22\x2f\x5c] strings are invalid in JSON strings
+and the module doesn't allow to C<decode> to these (except for \x2f).
+If C<$enable> is true (or missing), then C<decode>  will accept these
+unescaped strings.
+
+    $json->loose->decode(qq|["abc
+                                   def"]|);
+
+See to L<JSON::PP/JSON::PP OWN METHODS>.
+
+=head2 escape_slash
+
+    $json = $json->escape_slash([$enable])
+
+According to JSON Grammar, I<slash> (U+002F) is escaped. But by default
+JSON backend modules encode strings without escaping slash.
+
+If C<$enable> is true (or missing), then C<encode> will escape slashes.
+
+=head2 indent_length
+
+    $json = $json->indent_length($length)
+
+With JSON::XS, The indent space length is 3 and cannot be changed.
+With JSON::PP, it sets the indent space length with the given $length.
+The default is 3. The acceptable range is 0 to 15.
+
+=head2 sort_by
+
+    $json = $json->sort_by($function_name)
+    $json = $json->sort_by($subroutine_ref)
+
+If $function_name or $subroutine_ref are set, its sort routine are used.
+
+   $js = $pc->sort_by(sub { $JSON::PP::a cmp $JSON::PP::b })->encode($obj);
+   # is($js, q|{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9}|);
+
+   $js = $pc->sort_by('own_sort')->encode($obj);
+   # is($js, q|{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9}|);
+
+   sub JSON::PP::own_sort { $JSON::PP::a cmp $JSON::PP::b }
+
+As the sorting routine runs in the JSON::PP scope, the given
+subroutine name and the special variables C<$a>, C<$b> will begin
+with 'JSON::PP::'.
+
+If $integer is set, then the effect is same as C<canonical> on.
+
+See to L<JSON::PP/JSON::PP OWN METHODS>.
+
+=head1 MAPPING
+
+This section is copied from JSON::XS and modified to C<JSON>.
+JSON::XS and JSON::PP mapping mechanisms are almost equivalent.
+
+See to L<JSON::XS/MAPPING>.
+
+=head2 JSON -> PERL
+
+=over 4
+
+=item object
+
+A JSON object becomes a reference to a hash in Perl. No ordering of object
+keys is preserved (JSON does not preserver object key ordering itself).
+
+=item array
+
+A JSON array becomes a reference to an array in Perl.
+
+=item string
+
+A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
+are represented by the same codepoints in the Perl string, so no manual
+decoding is necessary.
+
+=item number
+
+A JSON number becomes either an integer, numeric (floating point) or
+string scalar in perl, depending on its range and any fractional parts. On
+the Perl level, there is no difference between those as Perl handles all
+the conversion details, but an integer may take slightly less memory and
+might represent more values exactly than floating point numbers.
+
+If the number consists of digits only, C<JSON> will try to represent
+it as an integer value. If that fails, it will try to represent it as
+a numeric (floating point) value if that is possible without loss of
+precision. Otherwise it will preserve the number as a string value (in
+which case you lose roundtripping ability, as the JSON number will be
+re-encoded toa JSON string).
+
+Numbers containing a fractional or exponential part will always be
+represented as numeric (floating point) values, possibly at a loss of
+precision (in which case you might lose perfect roundtripping ability, but
+the JSON number will still be re-encoded as a JSON number).
+
+Note that precision is not accuracy - binary floating point values cannot
+represent most decimal fractions exactly, and when converting from and to
+floating point, C<JSON> only guarantees precision up to but not including
+the leats significant bit.
+
+If the backend is JSON::PP and C<allow_bignum> is enable, the big integers
+and the numeric can be optionally converted into L<Math::BigInt> and
+L<Math::BigFloat> objects.
+
+=item true, false
+
+These JSON atoms become C<JSON::true> and C<JSON::false>,
+respectively. They are overloaded to act almost exactly like the numbers
+C<1> and C<0>. You can check wether a scalar is a JSON boolean by using
+the C<JSON::is_bool> function.
+
+If C<JSON::true> and C<JSON::false> are used as strings or compared as strings,
+they represent as C<true> and C<false> respectively.
+
+   print JSON::true . "\n";
+    => true
+   print JSON::true + 1;
+    => 1
+
+   ok(JSON::true eq 'true');
+   ok(JSON::true eq  '1');
+   ok(JSON::true == 1);
+
+C<JSON> will install these missing overloading features to the backend modules.
+
+
+=item null
+
+A JSON null atom becomes C<undef> in Perl.
+
+C<JSON::null> returns C<unddef>.
+
+=back
+
+
+=head2 PERL -> JSON
+
+The mapping from Perl to JSON is slightly more difficult, as Perl is a
+truly typeless language, so we can only guess which JSON type is meant by
+a Perl value.
+
+=over 4
+
+=item hash references
+
+Perl hash references become JSON objects. As there is no inherent ordering
+in hash keys (or JSON objects), they will usually be encoded in a
+pseudo-random order that can change between runs of the same program but
+stays generally the same within a single run of a program. C<JSON>
+optionally sort the hash keys (determined by the I<canonical> flag), so
+the same datastructure will serialise to the same JSON text (given same
+settings and version of JSON::XS), but this incurs a runtime overhead
+and is only rarely useful, e.g. when you want to compare some JSON text
+against another for equality.
+
+In future, the ordered object feature will be added to JSON::PP using C<tie> mechanism.
+
+
+=item array references
+
+Perl array references become JSON arrays.
+
+=item other references
+
+Other unblessed references are generally not allowed and will cause an
+exception to be thrown, except for references to the integers C<0> and
+C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
+also use C<JSON::false> and C<JSON::true> to improve readability.
+
+   to_json [\0,JSON::true]      # yields [false,true]
+
+=item JSON::true, JSON::false, JSON::null
+
+These special values become JSON true and JSON false values,
+respectively. You can also use C<\1> and C<\0> directly if you want.
+
+JSON::null returns C<undef>.
+
+=item blessed objects
+
+Blessed objects are not directly representable in JSON. See the
+C<allow_blessed> and C<convert_blessed> methods on various options on
+how to deal with this: basically, you can choose between throwing an
+exception, encoding the reference as if it weren't blessed, or provide
+your own serialiser method.
+
+With C<convert_blessed_universally> mode,  C<encode> converts blessed
+hash references or blessed array references (contains other blessed references)
+into JSON members and arrays.
+
+   use JSON -convert_blessed_universally;
+   JSON->new->allow_blessed->convert_blessed->encode( $blessed_object );
+
+See to L<convert_blessed>.
+
+=item simple scalars
+
+Simple Perl scalars (any scalar that is not a reference) are the most
+difficult objects to encode: JSON::XS and JSON::PP will encode undefined scalars as
+JSON C<null> values, scalars that have last been used in a string context
+before encoding as JSON strings, and anything else as number value:
+
+   # dump as number
+   encode_json [2]                      # yields [2]
+   encode_json [-3.0e17]                # yields [-3e+17]
+   my $value = 5; encode_json [$value]  # yields [5]
+
+   # used as string, so dump as string
+   print $value;
+   encode_json [$value]                 # yields ["5"]
+
+   # undef becomes null
+   encode_json [undef]                  # yields [null]
+
+You can force the type to be a string by stringifying it:
+
+   my $x = 3.1; # some variable containing a number
+   "$x";        # stringified
+   $x .= "";    # another, more awkward way to stringify
+   print $x;    # perl does it for you, too, quite often
+
+You can force the type to be a number by numifying it:
+
+   my $x = "3"; # some variable containing a string
+   $x += 0;     # numify it, ensuring it will be dumped as a number
+   $x *= 1;     # same thing, the choise is yours.
+
+You can not currently force the type in other, less obscure, ways.
+
+Note that numerical precision has the same meaning as under Perl (so
+binary to decimal conversion follows the same rules as in Perl, which
+can differ to other languages). Also, your perl interpreter might expose
+extensions to the floating point numbers of your platform, such as
+infinities or NaN's - these cannot be represented in JSON, and it is an
+error to pass those in.
+
+=item Big Number
+
+If the backend is JSON::PP and C<allow_bignum> is enable,
+C<encode> converts C<Math::BigInt> objects and C<Math::BigFloat>
+objects into JSON numbers.
+
+
+=back
+
+=head1 JSON and ECMAscript
+
+See to L<JSON::XS/JSON and ECMAscript>.
+
+=head1 JSON and YAML
+
+JSON is not a subset of YAML.
+See to L<JSON::XS/JSON and YAML>.
+
+
+=head1 BACKEND MODULE DECISION
+
+When you use C<JSON>, C<JSON> tries to C<use> JSON::XS. If this call failed, it will
+C<uses> JSON::PP. The required JSON::XS version is I<2.2> or later.
+
+The C<JSON> constructor method returns an object inherited from the backend module,
+and JSON::XS object is a blessed scaler reference while JSON::PP is a blessed hash
+reference.
+
+So, your program should not depend on the backend module, especially
+returned objects should not be modified.
+
+ my $json = JSON->new; # XS or PP?
+ $json->{stash} = 'this is xs object'; # this code may raise an error!
+
+To check the backend module, there are some methods - C<backend>, C<is_pp> and C<is_xs>.
+
+  JSON->backend; # 'JSON::XS' or 'JSON::PP'
+
+  JSON->backend->is_pp: # 0 or 1
+
+  JSON->backend->is_xs: # 1 or 0
+
+  $json->is_xs; # 1 or 0
+
+  $json->is_pp; # 0 or 1
+
+
+If you set an enviornment variable C<PERL_JSON_BACKEND>, The calling action will be changed.
+
+=over
+
+=item PERL_JSON_BACKEND = 0 or PERL_JSON_BACKEND = 'JSON::PP'
+
+Always use JSON::PP
+
+=item PERL_JSON_BACKEND == 1 or PERL_JSON_BACKEND = 'JSON::XS,JSON::PP'
+
+(The default) Use compiled JSON::XS if it is properly compiled & installed,
+otherwise use JSON::PP.
+
+=item PERL_JSON_BACKEND == 2 or PERL_JSON_BACKEND = 'JSON::XS'
+
+Always use compiled JSON::XS, die if it isn't properly compiled & installed.
+
+=item PERL_JSON_BACKEND = 'JSON::backportPP'
+
+Always use JSON::backportPP.
+JSON::backportPP is JSON::PP back port module.
+C<JSON> includs JSON::backportPP instead of JSON::PP.
+
+=back
+
+These ideas come from L<DBI::PurePerl> mechanism.
+
+example:
+
+ BEGIN { $ENV{PERL_JSON_BACKEND} = 'JSON::PP' }
+ use JSON; # always uses JSON::PP
+
+In future, it may be able to specify another module.
+
+=head1 USE PP FEATURES EVEN THOUGH XS BACKEND
+
+Many methods are available with either JSON::XS or JSON::PP and
+when the backend module is JSON::XS, if any JSON::PP specific (i.e. JSON::XS unspported)
+method is called, it will C<warn> and be noop.
+
+But If you C<use> C<JSON> passing the optional string C<-support_by_pp>,
+it makes a part of those unupported methods available.
+This feature is achieved by using JSON::PP in C<de/encode>.
+
+   BEGIN { $ENV{PERL_JSON_BACKEND} = 2 } # with JSON::XS
+   use JSON -support_by_pp;
+   my $json = new JSON;
+   $json->allow_nonref->escape_slash->encode("/");
+
+At this time, the returned object is a C<JSON::Backend::XS::Supportable>
+object (re-blessed XS object), and  by checking JSON::XS unsupported flags
+in de/encoding, can support some unsupported methods - C<loose>, C<allow_bignum>,
+C<allow_barekey>, C<allow_singlequote>, C<escape_slash> and C<indent_length>.
+
+When any unsupported methods are not enable, C<XS de/encode> will be
+used as is. The switch is achieved by changing the symbolic tables.
+
+C<-support_by_pp> is effective only when the backend module is JSON::XS
+and it makes the de/encoding speed down a bit.
+
+See to L<JSON::PP SUPPORT METHODS>.
+
+=head1 INCOMPATIBLE CHANGES TO OLD VERSION
+
+There are big incompatibility between new version (2.00) and old (1.xx).
+If you use old C<JSON> 1.xx in your code, please check it.
+
+See to L<Transition ways from 1.xx to 2.xx.>
+
+=over
+
+=item jsonToObj and objToJson are obsoleted.
+
+Non Perl-style name C<jsonToObj> and C<objToJson> are obsoleted
+(but not yet deleted from the source).
+If you use these functions in your code, please replace them
+with C<from_json> and C<to_json>.
+
+
+=item Global variables are no longer available.
+
+C<JSON> class variables - C<$JSON::AUTOCONVERT>, C<$JSON::BareKey>, etc...
+- are not available any longer.
+Instead, various features can be used through object methods.
+
+
+=item Package JSON::Converter and JSON::Parser are deleted.
+
+Now C<JSON> bundles with JSON::PP which can handle JSON more properly than them.
+
+=item Package JSON::NotString is deleted.
+
+There was C<JSON::NotString> class which represents JSON value C<true>, C<false>, C<null>
+and numbers. It was deleted and replaced by C<JSON::Boolean>.
+
+C<JSON::Boolean> represents C<true> and C<false>.
+
+C<JSON::Boolean> does not represent C<null>.
+
+C<JSON::null> returns C<undef>.
+
+C<JSON> makes L<JSON::XS::Boolean> and L<JSON::PP::Boolean> is-a relation
+to L<JSON::Boolean>.
+
+=item function JSON::Number is obsoleted.
+
+C<JSON::Number> is now needless because JSON::XS and JSON::PP have
+round-trip integrity.
+
+=item JSONRPC modules are deleted.
+
+Perl implementation of JSON-RPC protocol - C<JSONRPC >, C<JSONRPC::Transport::HTTP>
+and C<Apache::JSONRPC > are deleted in this distribution.
+Instead of them, there is L<JSON::RPC> which supports JSON-RPC protocol version 1.1.
+
+=back
+
+=head2 Transition ways from 1.xx to 2.xx.
+
+You should set C<suport_by_pp> mode firstly, because
+it is always successful for the below codes even with JSON::XS.
+
+    use JSON -support_by_pp;
+
+=over
+
+=item Exported jsonToObj (simple)
+
+  from_json($json_text);
+
+=item Exported objToJson (simple)
+
+  to_json($perl_scalar);
+
+=item Exported jsonToObj (advanced)
+
+  $flags = {allow_barekey => 1, allow_singlequote => 1};
+  from_json($json_text, $flags);
+
+equivalent to:
+
+  $JSON::BareKey = 1;
+  $JSON::QuotApos = 1;
+  jsonToObj($json_text);
+
+=item Exported objToJson (advanced)
+
+  $flags = {allow_blessed => 1, allow_barekey => 1};
+  to_json($perl_scalar, $flags);
+
+equivalent to:
+
+  $JSON::BareKey = 1;
+  objToJson($perl_scalar);
+
+=item jsonToObj as object method
+
+  $json->decode($json_text);
+
+=item objToJson as object method
+
+  $json->encode($perl_scalar);
+
+=item new method with parameters
+
+The C<new> method in 2.x takes any parameters no longer.
+You can set parameters instead;
+
+   $json = JSON->new->pretty;
+
+=item $JSON::Pretty, $JSON::Indent, $JSON::Delimiter
+
+If C<indent> is enable, that means C<$JSON::Pretty> flag set. And
+C<$JSON::Delimiter> was substituted by C<space_before> and C<space_after>.
+In conclusion:
+
+   $json->indent->space_before->space_after;
+
+Equivalent to:
+
+  $json->pretty;
+
+To change indent length, use C<indent_length>.
+
+(Only with JSON::PP, if C<-support_by_pp> is not used.)
+
+  $json->pretty->indent_length(2)->encode($perl_scalar);
+
+=item $JSON::BareKey
+
+(Only with JSON::PP, if C<-support_by_pp> is not used.)
+
+  $json->allow_barekey->decode($json_text)
+
+=item $JSON::ConvBlessed
+
+use C<-convert_blessed_universally>. See to L<convert_blessed>.
+
+=item $JSON::QuotApos
+
+(Only with JSON::PP, if C<-support_by_pp> is not used.)
+
+  $json->allow_singlequote->decode($json_text)
+
+=item $JSON::SingleQuote
+
+Disable. C<JSON> does not make such a invalid JSON string any longer.
+
+=item $JSON::KeySort
+
+  $json->canonical->encode($perl_scalar)
+
+This is the ascii sort.
+
+If you want to use with your own sort routine, check the C<sort_by> method.
+
+(Only with JSON::PP, even if C<-support_by_pp> is used currently.)
+
+  $json->sort_by($sort_routine_ref)->encode($perl_scalar)
+
+  $json->sort_by(sub { $JSON::PP::a <=> $JSON::PP::b })->encode($perl_scalar)
+
+Can't access C<$a> and C<$b> but C<$JSON::PP::a> and C<$JSON::PP::b>.
+
+=item $JSON::SkipInvalid
+
+  $json->allow_unknown
+
+=item $JSON::AUTOCONVERT
+
+Needless. C<JSON> backend modules have the round-trip integrity.
+
+=item $JSON::UTF8
+
+Needless because C<JSON> (JSON::XS/JSON::PP) sets
+the UTF8 flag on properly.
+
+    # With UTF8-flagged strings
+
+    $json->allow_nonref;
+    $str = chr(1000); # UTF8-flagged
+
+    $json_text  = $json->utf8(0)->encode($str);
+    utf8::is_utf8($json_text);
+    # true
+    $json_text  = $json->utf8(1)->encode($str);
+    utf8::is_utf8($json_text);
+    # false
+
+    $str = '"' . chr(1000) . '"'; # UTF8-flagged
+
+    $perl_scalar  = $json->utf8(0)->decode($str);
+    utf8::is_utf8($perl_scalar);
+    # true
+    $perl_scalar  = $json->utf8(1)->decode($str);
+    # died because of 'Wide character in subroutine'
+
+See to L<JSON::XS/A FEW NOTES ON UNICODE AND PERL>.
+
+=item $JSON::UnMapping
+
+Disable. See to L<MAPPING>.
+
+=item $JSON::SelfConvert
+
+This option was deleted.
+Instead of it, if a givien blessed object has the C<TO_JSON> method,
+C<TO_JSON> will be executed with C<convert_blessed>.
+
+  $json->convert_blessed->encode($bleesed_hashref_or_arrayref)
+  # if need, call allow_blessed
+
+Note that it was C<toJson> in old version, but now not C<toJson> but C<TO_JSON>.
+
+=back
+
+=head1 TODO
+
+=over
+
+=item example programs
+
+=back
+
+=head1 THREADS
+
+No test with JSON::PP. If with JSON::XS, See to L<JSON::XS/THREADS>.
+
+
+=head1 BUGS
+
+Please report bugs relevant to C<JSON> to E<lt>makamaka[at]cpan.orgE<gt>.
+
+
+=head1 SEE ALSO
+
+Most of the document is copied and modified from JSON::XS doc.
+
+L<JSON::XS>, L<JSON::PP>
+
+C<RFC4627>(L<http://www.ietf.org/rfc/rfc4627.txt>)
+
+=head1 AUTHOR
+
+Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
+
+JSON::XS was written by  Marc Lehmann <schmorp[at]schmorp.de>
+
+The relese of this new version owes to the courtesy of Marc Lehmann.
+
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2005-2011 by Makamaka Hannyaharamitu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut
+
diff --git a/test/helloworld/Makefile b/test/helloworld/Makefile
new file mode 100644
index 0000000..0570a84
--- /dev/null
+++ b/test/helloworld/Makefile
@@ -0,0 +1,90 @@
+export RV_ROOT = ${PWD}/../..
+RV_DESIGN = ${RV_ROOT}/design
+
+TEST_CFLAGS = -g -O3 -funroll-all-loops
+ABI = -mabi=ilp32 -march=rv32imc
+
+# Allow snapshot override
+target = default
+
+# Allow tool override
+VERILATOR = verilator
+GCC_PREFIX = /opt/riscv/bin/riscv64-unknown-elf
+TESTDIR = ${PWD}
+BUILD_DIR = ${TESTDIR}/build
+SWERV_CONFIG = ${TESTDIR}/swerv.config
+
+TEST = hello_world
+
+ifdef debug
+ DEBUG_PLUS = +dumpon
+ VERILATOR_DEBUG = --trace
+endif
+
+LINK = $(TESTDIR)/link.ld
+
+OFILES = $(TEST).o
+
+VPATH = $(BUILD_DIR) $(TESTDIR)
+TESTFILES = $(TESTDIR)/tb_top.sv $(TESTDIR)/ahb_sif.sv
+
+defines = $(BUILD_DIR)/common_defines.vh ${RV_DESIGN}/include/swerv_types.sv
+includes = -I${RV_DESIGN}/include -I${RV_DESIGN}/lib  -I${BUILD_DIR}
+
+# CFLAGS for verilator generated Makefiles. Without -std=c++11 it complains for `auto` variables
+CFLAGS += "-std=c++11"
+# Optimization for better performance; alternative is nothing for slower runtime (faster compiles)
+# -O2 for faster runtime (slower compiles), or -O for balance.
+VERILATOR_MAKE_FLAGS = OPT_FAST="-Os"
+
+# Targets
+all: clean verilator
+
+clean:
+	rm -rf build obj_dir
+	# *.log *.hex *.dis *.tbl simv* *.map snapshots \
+	# verilator* *.exe obj* *.o hello_world.cpp.s ucli.key vc_hdrs.h csrc *.csv \
+	# work dataset.asdb  library.cfg hello_world.o
+
+# If define files do not exist, then run swerv.config.
+${BUILD_DIR}/defines.h :
+	BUILD_PATH=${BUILD_DIR} ${SWERV_CONFIG} -target=$(target) -set iccm_enable
+
+##################### Verilog Builds #####################################
+
+verilator-build: ${TESTFILES} ${BUILD_DIR}/defines.h test_tb_top.cpp
+	echo '`undef ASSERT_ON' >> ${BUILD_DIR}/common_defines.vh
+	$(VERILATOR) --cc -CFLAGS ${CFLAGS} $(defines) $(includes) \
+	              -Wno-UNOPTFLAT \
+	              -I${TESTDIR} \
+		            -f ${TESTDIR}/flist \
+	              ${TESTFILES} \
+	              --top-module tb_top -exe test_tb_top.cpp --autoflush $(VERILATOR_DEBUG)
+	cp ${TESTDIR}/test_tb_top.cpp obj_dir
+	$(MAKE) -j -C obj_dir/ -f Vtb_top.mk $(VERILATOR_MAKE_FLAGS)
+
+##################### Simulation Runs #####################################
+
+verilator: program.hex verilator-build
+	cd build && ../obj_dir/Vtb_top ${DEBUG_PLUS}
+
+##################### Test Build #####################################
+
+program.hex: $(OFILES) $(LINK)
+	@echo Building $(TEST)
+	$(GCC_PREFIX)-gcc $(ABI) -Wl,-Map=$(BUILD_DIR)/$(TEST).map -lgcc -T$(LINK) -o $(BUILD_DIR)/$(TEST).exe $(BUILD_DIR)/$(OFILES) -nostartfiles  $(TEST_LIBS)
+	$(GCC_PREFIX)-objcopy -O verilog $(BUILD_DIR)/$(TEST).exe $(BUILD_DIR)/program.hex
+	$(GCC_PREFIX)-objdump -S  $(BUILD_DIR)/$(TEST).exe > $(BUILD_DIR)/$(TEST).dis
+	@echo Completed building $(TEST)
+
+%.o : %.s ${BUILD_DIR}/defines.h
+	$(GCC_PREFIX)-cpp -I${BUILD_DIR}  $<  > $(BUILD_DIR)/$*.cpp.s
+	$(GCC_PREFIX)-as $(ABI) $(BUILD_DIR)/$*.cpp.s -o $(BUILD_DIR)/$@
+
+%.o : %.c ${BUILD_DIR}/defines.h
+	$(GCC_PREFIX)-gcc -I${BUILD_DIR} ${TEST_CFLAGS} ${ABI} -nostdlib -c $< -o $(BUILD_DIR)/$@
+
+help:
+	@echo Possible targets: verilator help clean all verilator-build program.hex
+
+.PHONY: help clean verilator
diff --git a/test/helloworld/ahb_sif copy.sv b/test/helloworld/ahb_sif copy.sv
new file mode 100644
index 0000000..9143016
--- /dev/null
+++ b/test/helloworld/ahb_sif copy.sv	
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2019 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+`ifdef RV_BUILD_AHB_LITE
+
+module ahb_sif (
+input logic [63:0] HWDATA,
+input logic HCLK,
+input logic HSEL,
+input logic [3:0] HPROT,
+input logic HWRITE,
+input logic [1:0] HTRANS,
+input logic [2:0] HSIZE,
+input logic HREADY,
+input logic HRESETn,
+input logic [31:0] HADDR,
+input logic [2:0] HBURST,
+
+output logic HREADYOUT,
+output logic HRESP,
+output logic [63:0] HRDATA
+);
+
+parameter MAILBOX_ADDR = 32'hD0580000;
+
+logic write;
+logic [31:0] laddr, addr;
+logic [7:0] strb_lat;
+logic [63:0] rdata;
+
+bit [7:0] mem [bit[31:0]];
+bit [7:0] wscnt;
+int dws = 0;
+int iws = 0;
+bit dws_rand;
+bit iws_rand;
+bit ok;
+
+// Wires
+wire [63:0] WriteData = HWDATA;
+wire [7:0] strb =  HSIZE == 3'b000 ? 8'h1 << HADDR[2:0] :
+                   HSIZE == 3'b001 ? 8'h3 << {HADDR[2:1],1'b0} :
+                   HSIZE == 3'b010 ? 8'hf << {HADDR[2],2'b0} : 8'hff;
+
+
+wire mailbox_write = write && laddr==MAILBOX_ADDR;
+
+
+initial begin
+    if ($value$plusargs("iws=%d", iws));
+    if ($value$plusargs("dws=%d", dws));
+    dws_rand = dws < 0;
+    iws_rand = iws < 0;
+end
+
+
+
+always @ (negedge HCLK ) begin
+    if(HREADY)
+        addr = HADDR;
+    if (write & HREADY) begin
+        if(strb_lat[7]) mem[{laddr[31:3],3'd7}] = HWDATA[63:56];
+        if(strb_lat[6]) mem[{laddr[31:3],3'd6}] = HWDATA[55:48];
+        if(strb_lat[5]) mem[{laddr[31:3],3'd5}] = HWDATA[47:40];
+        if(strb_lat[4]) mem[{laddr[31:3],3'd4}] = HWDATA[39:32];
+        if(strb_lat[3]) mem[{laddr[31:3],3'd3}] = HWDATA[31:24];
+        if(strb_lat[2]) mem[{laddr[31:3],3'd2}] = HWDATA[23:16];
+        if(strb_lat[1]) mem[{laddr[31:3],3'd1}] = HWDATA[15:08];
+        if(strb_lat[0]) mem[{laddr[31:3],3'd0}] = HWDATA[07:00];
+    end
+    if(HREADY & HSEL & |HTRANS) begin
+`ifdef VERILATOR
+        if(iws_rand & ~HPROT[0])
+            iws = $random & 15;
+        if(dws_rand & HPROT[0])
+            dws = $random & 15;
+`else
+        if(iws_rand & ~HPROT[0])
+            ok = std::randomize(iws) with {iws dist {0:=10, [1:3]:/2, [4:15]:/1};};
+        if(dws_rand & HPROT[0])
+            ok = std::randomize(dws) with {dws dist {0:=10, [1:3]:/2, [4:15]:/1};};
+`endif
+    end
+end
+
+
+assign HRDATA = HREADY ? rdata : ~rdata;
+assign HREADYOUT = wscnt == 0;
+assign HRESP = 0;
+
+always @(posedge HCLK or negedge HRESETn) begin
+    if(~HRESETn) begin
+        laddr <= 32'b0;
+        write <= 1'b0;
+        rdata <= '0;
+        wscnt <= 0;
+    end
+    else begin
+        if(HREADY & HSEL) begin
+            laddr <= HADDR;
+            write <= HWRITE & |HTRANS;
+            if(|HTRANS & ~HWRITE)
+                rdata <= {mem[{addr[31:3],3'd7}],
+                          mem[{addr[31:3],3'd6}],
+                          mem[{addr[31:3],3'd5}],
+                          mem[{addr[31:3],3'd4}],
+                          mem[{addr[31:3],3'd3}],
+                          mem[{addr[31:3],3'd2}],
+                          mem[{addr[31:3],3'd1}],
+                          mem[{addr[31:3],3'd0}]};
+            strb_lat <= strb;
+        end
+    end
+    if(HREADY & HSEL & |HTRANS)
+        wscnt <= HPROT[0] ? dws[7:0] : iws[7:0];
+    else if(wscnt != 0)
+        wscnt <= wscnt-1;
+end
+
+
+endmodule
+`endif
+
+`ifdef RV_BUILD_AXI4
+module axi_slv #(TAGW=1) (
+input                   aclk,
+input                   rst_l,
+input                   arvalid,
+output reg              arready,
+input [31:0]            araddr,
+input [TAGW-1:0]        arid,
+input [7:0]             arlen,
+input [1:0]             arburst,
+input [2:0]             arsize,
+
+output reg              rvalid,
+input                   rready,
+output reg [63:0]       rdata,
+output reg [1:0]        rresp,
+output reg [TAGW-1:0]   rid,
+output                  rlast,
+
+input                   awvalid,
+output                  awready,
+input [31:0]            awaddr,
+input [TAGW-1:0]        awid,
+input [7:0]             awlen,
+input [1:0]             awburst,
+input [2:0]             awsize,
+
+input [63:0]            wdata,
+input [7:0]             wstrb,
+input                   wvalid,
+output                  wready,
+
+output  reg             bvalid,
+input                   bready,
+output reg [1:0]        bresp,
+output reg [TAGW-1:0]   bid
+);
+
+parameter MAILBOX_ADDR = 32'hD0580000;
+parameter MEM_SIZE_DW = 8192;
+
+bit [7:0] mem [bit[31:0]];
+bit [63:0] memdata;
+wire [63:0] WriteData;
+wire mailbox_write;
+
+
+assign mailbox_write = awvalid && awaddr==MAILBOX_ADDR && rst_l;
+assign WriteData = wdata;
+
+always @ ( posedge aclk or negedge rst_l) begin
+    if(!rst_l) begin
+        rvalid  <= 0;
+        bvalid  <= 0;
+    end
+    else begin
+        bid     <= awid;
+        rid     <= arid;
+        rvalid  <= arvalid;
+        bvalid  <= awvalid;
+        rdata   <= memdata;
+    end
+end
+
+always @ ( negedge aclk) begin
+    if(arvalid) memdata <= {mem[araddr+7], mem[araddr+6], mem[araddr+5], mem[araddr+4],
+                            mem[araddr+3], mem[araddr+2], mem[araddr+1], mem[araddr]};
+    if(awvalid) begin
+        if(wstrb[7]) mem[awaddr+7] = wdata[63:56];
+        if(wstrb[6]) mem[awaddr+6] = wdata[55:48];
+        if(wstrb[5]) mem[awaddr+5] = wdata[47:40];
+        if(wstrb[4]) mem[awaddr+4] = wdata[39:32];
+        if(wstrb[3]) mem[awaddr+3] = wdata[31:24];
+        if(wstrb[2]) mem[awaddr+2] = wdata[23:16];
+        if(wstrb[1]) mem[awaddr+1] = wdata[15:08];
+        if(wstrb[0]) mem[awaddr+0] = wdata[07:00];
+    end
+end
+
+
+assign arready = 1'b1;
+assign awready = 1'b1;
+assign wready  = 1'b1;
+assign rresp   = 2'b0;
+assign bresp   = 2'b0;
+assign rlast   = 1'b1;
+
+endmodule
+`endif
+
diff --git a/test/helloworld/ahb_sif.sv b/test/helloworld/ahb_sif.sv
new file mode 100644
index 0000000..9143016
--- /dev/null
+++ b/test/helloworld/ahb_sif.sv
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2019 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+`ifdef RV_BUILD_AHB_LITE
+
+module ahb_sif (
+input logic [63:0] HWDATA,
+input logic HCLK,
+input logic HSEL,
+input logic [3:0] HPROT,
+input logic HWRITE,
+input logic [1:0] HTRANS,
+input logic [2:0] HSIZE,
+input logic HREADY,
+input logic HRESETn,
+input logic [31:0] HADDR,
+input logic [2:0] HBURST,
+
+output logic HREADYOUT,
+output logic HRESP,
+output logic [63:0] HRDATA
+);
+
+parameter MAILBOX_ADDR = 32'hD0580000;
+
+logic write;
+logic [31:0] laddr, addr;
+logic [7:0] strb_lat;
+logic [63:0] rdata;
+
+bit [7:0] mem [bit[31:0]];
+bit [7:0] wscnt;
+int dws = 0;
+int iws = 0;
+bit dws_rand;
+bit iws_rand;
+bit ok;
+
+// Wires
+wire [63:0] WriteData = HWDATA;
+wire [7:0] strb =  HSIZE == 3'b000 ? 8'h1 << HADDR[2:0] :
+                   HSIZE == 3'b001 ? 8'h3 << {HADDR[2:1],1'b0} :
+                   HSIZE == 3'b010 ? 8'hf << {HADDR[2],2'b0} : 8'hff;
+
+
+wire mailbox_write = write && laddr==MAILBOX_ADDR;
+
+
+initial begin
+    if ($value$plusargs("iws=%d", iws));
+    if ($value$plusargs("dws=%d", dws));
+    dws_rand = dws < 0;
+    iws_rand = iws < 0;
+end
+
+
+
+always @ (negedge HCLK ) begin
+    if(HREADY)
+        addr = HADDR;
+    if (write & HREADY) begin
+        if(strb_lat[7]) mem[{laddr[31:3],3'd7}] = HWDATA[63:56];
+        if(strb_lat[6]) mem[{laddr[31:3],3'd6}] = HWDATA[55:48];
+        if(strb_lat[5]) mem[{laddr[31:3],3'd5}] = HWDATA[47:40];
+        if(strb_lat[4]) mem[{laddr[31:3],3'd4}] = HWDATA[39:32];
+        if(strb_lat[3]) mem[{laddr[31:3],3'd3}] = HWDATA[31:24];
+        if(strb_lat[2]) mem[{laddr[31:3],3'd2}] = HWDATA[23:16];
+        if(strb_lat[1]) mem[{laddr[31:3],3'd1}] = HWDATA[15:08];
+        if(strb_lat[0]) mem[{laddr[31:3],3'd0}] = HWDATA[07:00];
+    end
+    if(HREADY & HSEL & |HTRANS) begin
+`ifdef VERILATOR
+        if(iws_rand & ~HPROT[0])
+            iws = $random & 15;
+        if(dws_rand & HPROT[0])
+            dws = $random & 15;
+`else
+        if(iws_rand & ~HPROT[0])
+            ok = std::randomize(iws) with {iws dist {0:=10, [1:3]:/2, [4:15]:/1};};
+        if(dws_rand & HPROT[0])
+            ok = std::randomize(dws) with {dws dist {0:=10, [1:3]:/2, [4:15]:/1};};
+`endif
+    end
+end
+
+
+assign HRDATA = HREADY ? rdata : ~rdata;
+assign HREADYOUT = wscnt == 0;
+assign HRESP = 0;
+
+always @(posedge HCLK or negedge HRESETn) begin
+    if(~HRESETn) begin
+        laddr <= 32'b0;
+        write <= 1'b0;
+        rdata <= '0;
+        wscnt <= 0;
+    end
+    else begin
+        if(HREADY & HSEL) begin
+            laddr <= HADDR;
+            write <= HWRITE & |HTRANS;
+            if(|HTRANS & ~HWRITE)
+                rdata <= {mem[{addr[31:3],3'd7}],
+                          mem[{addr[31:3],3'd6}],
+                          mem[{addr[31:3],3'd5}],
+                          mem[{addr[31:3],3'd4}],
+                          mem[{addr[31:3],3'd3}],
+                          mem[{addr[31:3],3'd2}],
+                          mem[{addr[31:3],3'd1}],
+                          mem[{addr[31:3],3'd0}]};
+            strb_lat <= strb;
+        end
+    end
+    if(HREADY & HSEL & |HTRANS)
+        wscnt <= HPROT[0] ? dws[7:0] : iws[7:0];
+    else if(wscnt != 0)
+        wscnt <= wscnt-1;
+end
+
+
+endmodule
+`endif
+
+`ifdef RV_BUILD_AXI4
+module axi_slv #(TAGW=1) (
+input                   aclk,
+input                   rst_l,
+input                   arvalid,
+output reg              arready,
+input [31:0]            araddr,
+input [TAGW-1:0]        arid,
+input [7:0]             arlen,
+input [1:0]             arburst,
+input [2:0]             arsize,
+
+output reg              rvalid,
+input                   rready,
+output reg [63:0]       rdata,
+output reg [1:0]        rresp,
+output reg [TAGW-1:0]   rid,
+output                  rlast,
+
+input                   awvalid,
+output                  awready,
+input [31:0]            awaddr,
+input [TAGW-1:0]        awid,
+input [7:0]             awlen,
+input [1:0]             awburst,
+input [2:0]             awsize,
+
+input [63:0]            wdata,
+input [7:0]             wstrb,
+input                   wvalid,
+output                  wready,
+
+output  reg             bvalid,
+input                   bready,
+output reg [1:0]        bresp,
+output reg [TAGW-1:0]   bid
+);
+
+parameter MAILBOX_ADDR = 32'hD0580000;
+parameter MEM_SIZE_DW = 8192;
+
+bit [7:0] mem [bit[31:0]];
+bit [63:0] memdata;
+wire [63:0] WriteData;
+wire mailbox_write;
+
+
+assign mailbox_write = awvalid && awaddr==MAILBOX_ADDR && rst_l;
+assign WriteData = wdata;
+
+always @ ( posedge aclk or negedge rst_l) begin
+    if(!rst_l) begin
+        rvalid  <= 0;
+        bvalid  <= 0;
+    end
+    else begin
+        bid     <= awid;
+        rid     <= arid;
+        rvalid  <= arvalid;
+        bvalid  <= awvalid;
+        rdata   <= memdata;
+    end
+end
+
+always @ ( negedge aclk) begin
+    if(arvalid) memdata <= {mem[araddr+7], mem[araddr+6], mem[araddr+5], mem[araddr+4],
+                            mem[araddr+3], mem[araddr+2], mem[araddr+1], mem[araddr]};
+    if(awvalid) begin
+        if(wstrb[7]) mem[awaddr+7] = wdata[63:56];
+        if(wstrb[6]) mem[awaddr+6] = wdata[55:48];
+        if(wstrb[5]) mem[awaddr+5] = wdata[47:40];
+        if(wstrb[4]) mem[awaddr+4] = wdata[39:32];
+        if(wstrb[3]) mem[awaddr+3] = wdata[31:24];
+        if(wstrb[2]) mem[awaddr+2] = wdata[23:16];
+        if(wstrb[1]) mem[awaddr+1] = wdata[15:08];
+        if(wstrb[0]) mem[awaddr+0] = wdata[07:00];
+    end
+end
+
+
+assign arready = 1'b1;
+assign awready = 1'b1;
+assign wready  = 1'b1;
+assign rresp   = 2'b0;
+assign bresp   = 2'b0;
+assign rlast   = 1'b1;
+
+endmodule
+`endif
+
diff --git a/test/helloworld/axi_lsu_dma_bridge.sv b/test/helloworld/axi_lsu_dma_bridge.sv
new file mode 100644
index 0000000..2c3b844
--- /dev/null
+++ b/test/helloworld/axi_lsu_dma_bridge.sv
@@ -0,0 +1,201 @@
+
+// connects LSI master to external AXI slave and DMA slave
+module axi_lsu_dma_bridge
+#(
+parameter M_ID_WIDTH = 8,
+parameter S0_ID_WIDTH = 8
+)
+(
+input                   clk,
+input                   reset_l,
+
+// master read bus
+input                   m_arvalid,
+input [M_ID_WIDTH-1:0]  m_arid,
+input[31:0]             m_araddr,
+output                  m_arready,
+
+output                  m_rvalid,
+input                   m_rready,
+output [63:0]           m_rdata,
+output [M_ID_WIDTH-1:0] m_rid,
+output [1:0]            m_rresp,
+output                  m_rlast,
+
+// master write bus
+input                   m_awvalid,
+input [M_ID_WIDTH-1:0]  m_awid,
+input[31:0]             m_awaddr,
+output                  m_awready,
+
+input                   m_wvalid,
+output                  m_wready,
+
+output[1:0]             m_bresp,
+output                  m_bvalid,
+output[M_ID_WIDTH-1:0]  m_bid,
+input                   m_bready,
+
+// slave 0 if general ext memory
+output                  s0_arvalid,
+input                   s0_arready,
+
+input                   s0_rvalid,
+input[S0_ID_WIDTH-1:0]  s0_rid,
+input[1:0]              s0_rresp,
+input[63:0]             s0_rdata,
+input                   s0_rlast,
+output                  s0_rready,
+
+output                  s0_awvalid,
+input                   s0_awready,
+
+output                  s0_wvalid,
+input                   s0_wready,
+
+input[1:0]              s0_bresp,
+input                   s0_bvalid,
+input[S0_ID_WIDTH-1:0]  s0_bid,
+output                  s0_bready,
+
+// slave 1 if DMA port
+output                  s1_arvalid,
+input                   s1_arready,
+
+input                   s1_rvalid,
+input[1:0]              s1_rresp,
+input[63:0]             s1_rdata,
+input                   s1_rlast,
+output                  s1_rready,
+
+output                  s1_awvalid,
+input                   s1_awready,
+
+output                  s1_wvalid,
+input                   s1_wready,
+
+input[1:0]              s1_bresp,
+input                   s1_bvalid,
+output                  s1_bready
+);
+
+parameter ICCM_BASE = `RV_ICCM_BITS; // in LSBs
+localparam IDFIFOSZ = $clog2(`RV_DMA_BUF_DEPTH);
+bit[31:0] iccm_real_base_addr = `RV_ICCM_SADR ;
+
+wire ar_slave_select;
+wire aw_slave_select;
+wire w_slave_select;
+
+wire rresp_select;
+wire bresp_select;
+wire ar_iccm_select;
+wire aw_iccm_select;
+
+reg [1:0] wsel_iptr, wsel_optr;
+reg [2:0] wsel_count;
+reg [3:0] wsel;
+
+
+reg [M_ID_WIDTH-1:0] arid [1<<IDFIFOSZ];
+reg [M_ID_WIDTH-1:0] awid [1<<IDFIFOSZ];
+reg [IDFIFOSZ-1:0] arid_cnt;
+reg [IDFIFOSZ-1:0] awid_cnt;
+reg [IDFIFOSZ-1:0] rid_cnt;
+reg [IDFIFOSZ-1:0] bid_cnt;
+
+
+// 1 select slave 1; 0 - slave 0
+assign ar_slave_select = ar_iccm_select;
+assign aw_slave_select = aw_iccm_select;
+
+assign ar_iccm_select = m_araddr[31:ICCM_BASE] == iccm_real_base_addr[31:ICCM_BASE];
+assign aw_iccm_select = m_awaddr[31:ICCM_BASE] == iccm_real_base_addr[31:ICCM_BASE];
+
+assign s0_arvalid = m_arvalid & ~ar_slave_select;
+assign s1_arvalid = m_arvalid &  ar_slave_select;
+assign m_arready = ar_slave_select ? s1_arready : s0_arready;
+
+
+assign s0_awvalid = m_awvalid & ~aw_slave_select;
+assign s1_awvalid = m_awvalid & aw_slave_select;
+assign m_awready = aw_slave_select ? s1_awready : s0_awready;
+
+
+assign s0_wvalid = m_wvalid & ~w_slave_select;
+assign s1_wvalid = m_wvalid &  w_slave_select;
+assign m_wready = w_slave_select ? s1_wready : s0_wready;
+assign w_slave_select = (wsel_count == 0 || wsel_count[2]) ? aw_slave_select : wsel[wsel_optr];
+
+assign m_rvalid = s0_rvalid | s1_rvalid;
+assign s0_rready = m_rready & ~rresp_select;
+assign s1_rready = m_rready &  rresp_select;
+assign m_rdata = rresp_select ? s1_rdata : s0_rdata;
+assign m_rresp = rresp_select ? s1_rresp : s0_rresp;
+assign m_rid = rresp_select ? arid[rid_cnt] : s0_rid;
+assign m_rlast = rresp_select ? s1_rlast : s0_rlast;
+
+assign rresp_select = s1_rvalid & ~s0_rvalid;
+
+assign m_bvalid = s0_bvalid | s1_bvalid;
+assign s0_bready = m_bready & ~bresp_select;
+assign s1_bready = m_bready &  bresp_select;
+assign m_bid = bresp_select ? awid[bid_cnt] : s0_bid;
+assign m_bresp = bresp_select ? s1_bresp : s0_bresp;
+
+
+assign bresp_select = s1_bvalid & ~s0_bvalid;
+
+
+// W-channel select fifo
+always @ (posedge clk or negedge reset_l)
+    if(!reset_l) begin
+        wsel_count <= '0;
+        wsel_iptr <= '0;
+        wsel_optr <= '0;
+    end
+    else begin
+        if(m_awvalid & m_awready) begin
+            wsel[wsel_iptr] <= aw_slave_select;
+            if(!(m_wready & m_wvalid )) wsel_count <= wsel_count + 1;
+            wsel_iptr <= wsel_iptr + 1;
+        end
+        if(m_wvalid & m_wready) begin
+           if(!(m_awready & m_awvalid ) ) wsel_count <= wsel_count - 1;
+           wsel_optr <= wsel_optr + 1;
+        end
+    end
+
+// id replacement for narrow ID slave
+always @ (posedge clk or negedge reset_l)
+    if(!reset_l) begin
+        arid_cnt <= '0;
+        rid_cnt <= '0;
+    end
+    else begin
+        if(ar_slave_select & m_arready & m_arvalid) begin
+            arid[arid_cnt] <= m_arid;
+            arid_cnt <= arid_cnt + 1;
+        end
+        if(rresp_select & m_rready & m_rvalid) begin
+            rid_cnt <= rid_cnt + 1;
+        end
+
+    end
+
+always @ (posedge clk or negedge reset_l)
+    if(!reset_l) begin
+        awid_cnt <= '0;
+        bid_cnt <= '0;
+    end
+    else begin
+        if(aw_slave_select & m_awready & m_awvalid) begin
+            awid[awid_cnt] <= m_awid;
+            awid_cnt <= awid_cnt + 1;
+        end
+        if(bresp_select & m_bready & m_bvalid) begin
+            bid_cnt <= bid_cnt + 1;
+        end
+    end
+
+endmodule
diff --git a/test/helloworld/dasm.svi b/test/helloworld/dasm.svi
new file mode 100644
index 0000000..aef232c
--- /dev/null
+++ b/test/helloworld/dasm.svi
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2019 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Run time disassembler functions
+// supports  RISCV extentions I, C, M, A
+`ifndef RV_NUM_THREADS
+`define RV_NUM_THREADS 1
+`endif
+
+bit[31:0] [31:0] gpr[`RV_NUM_THREADS];
+
+// main DASM function
+function string dasm(input[31:0] opcode, input[31:0] pc, input[4:0] regn, input[31:0] regv, input tid=0);
+    dasm = (opcode[1:0] == 2'b11) ? dasm32(opcode, pc, tid) : dasm16(opcode, pc, tid);
+    if(regn) gpr[tid][regn] = regv;
+endfunction
+
+
+///////////////// 16 bits instructions ///////////////////////
+
+function string dasm16( input[31:0] opcode, input[31:0] pc, input tid=0);
+    case(opcode[1:0])
+    0: return dasm16_0(opcode, tid);
+    1: return dasm16_1(opcode, pc);
+    2: return dasm16_2(opcode);
+    endcase
+    return $sformatf(".short 0x%h", opcode[15:0]);
+endfunction
+
+function string dasm16_0( input[31:0] opcode, tid);
+    case(opcode[15:13])
+    3'b000: return dasm16_ciw(opcode);
+    3'b001: return {"c.fld  ", dasm16_cl(opcode, tid)};
+    3'b010: return {"c.lw   ", dasm16_cl(opcode, tid)};
+    3'b011: return {"c.flw  ", dasm16_cl(opcode, tid)};
+    3'b101: return {"c.fsd  ", dasm16_cl(opcode, tid)};
+    3'b110: return {"c.sw   ", dasm16_cl(opcode, tid)};
+    3'b111: return {"c.fsw  ", dasm16_cl(opcode, tid)};
+    endcase
+    return $sformatf(".short  0x%h", opcode[15:0]);
+endfunction
+
+function string dasm16_ciw( input[31:0] opcode);
+int imm;
+    imm=0;
+    if(opcode[15:0] == 0) return ".short  0";
+    {imm[5:4],imm[9:6],imm[2],imm[3]} = opcode[12:5];
+    return $sformatf("c.addi4spn %s,0x%0h", abi_reg[opcode[4:2]+8], imm);
+endfunction
+
+function string dasm16_cl( input[31:0] opcode, input tid=0);
+int imm;
+    imm=0;
+    imm[5:3] = opcode[12:10];
+    imm[7:6] = opcode[6:5];
+
+    return $sformatf(" %s,%0d(%s) [%h]", abi_reg[opcode[4:2]+8], imm, abi_reg[opcode[9:7]+8], gpr[tid][opcode[9:7]+8]+imm);
+endfunction
+
+function string dasm16_1( input[31:0] opcode, input[31:0] pc);
+    case(opcode[15:13])
+    3'b000: return opcode[11:7]==0 ? "c.nop" : {"c.addi  ",dasm16_ci(opcode)};
+    3'b001: return {"c.jal   ", dasm16_cj(opcode, pc)};
+    3'b010: return {"c.li    ", dasm16_ci(opcode)};
+    3'b011: return dasm16_1_3(opcode);
+    3'b100: return dasm16_cr(opcode);
+    3'b101: return {"c.j     ", dasm16_cj(opcode, pc)};
+    3'b110: return {"c.beqz  ", dasm16_cb(opcode, pc)};
+    3'b111: return {"c.bnez  ", dasm16_cb(opcode, pc)};
+    endcase
+endfunction
+
+function string dasm16_ci( input[31:0] opcode);
+int imm;
+    imm=0;
+    imm[4:0] = opcode[6:2];
+    if(opcode[12]) imm [31:5] = '1;
+    return $sformatf("%s,%0d", abi_reg[opcode[11:7]], imm);
+endfunction
+
+function string dasm16_cj( input[31:0] opcode, input[31:0] pc);
+bit[31:0] imm;
+    imm=0;
+    {imm[11],imm[4],imm[9:8],imm[10],imm[6], imm[7],imm[3:1], imm[5]} = opcode[12:2];
+    if(opcode[12]) imm [31:12] = '1;
+    return $sformatf("0x%0h", imm+pc);
+endfunction
+
+function string dasm16_cb( input[31:0] opcode, input[31:0] pc);
+bit[31:0] imm;
+    imm=0;
+    {imm[8],imm[4:3]} = opcode[12:10];
+    {imm[7:6],imm[2:1], imm[5]} = opcode[6:2];
+    if(opcode[12]) imm [31:9] = '1;
+    return $sformatf("%s,0x%0h",abi_reg[opcode[9:7]+8], imm+pc);
+endfunction
+
+function string dasm16_cr( input[31:0] opcode);
+bit[31:0] imm;
+
+    imm = 0;
+    imm[4:0] = opcode[6:2];
+    if(opcode[5]) imm [31:5] = '1;
+    case(opcode[11:10])
+    0: return $sformatf("c.srli  %s,%0d",  abi_reg[opcode[9:7]+8], imm[5:0]);
+    1: return $sformatf("c.srai  %s,%0d",  abi_reg[opcode[9:7]+8], imm[5:0]);
+    2: return $sformatf("c.andi  %s,0x%0h", abi_reg[opcode[9:7]+8], imm);
+    endcase
+
+    case(opcode[6:5])
+    0: return $sformatf("c.sub   %s,%s", abi_reg[opcode[9:7]+8], abi_reg[opcode[4:2]+8]);
+    1: return $sformatf("c.xor   %s,%s", abi_reg[opcode[9:7]+8], abi_reg[opcode[4:2]+8]);
+    2: return $sformatf("c.or    %s,%s", abi_reg[opcode[9:7]+8], abi_reg[opcode[4:2]+8]);
+    3: return $sformatf("c.and   %s,%s", abi_reg[opcode[9:7]+8], abi_reg[opcode[4:2]+8]);
+    endcase
+endfunction
+
+function string dasm16_1_3( input[31:0] opcode);
+int imm;
+
+    imm=0;
+    if(opcode[11:7] == 2) begin
+        {imm[4], imm[6],imm[8:7], imm[5]} = opcode[6:2];
+        if(opcode[12]) imm [31:9] = '1;
+        return $sformatf("c.addi16sp %0d", imm);
+    end
+    else begin
+        imm[16:12] = opcode[6:2];
+        if(opcode[12]) imm [31:17] = '1;
+        return $sformatf("c.lui   %s,0x%0h", abi_reg[opcode[11:7]], imm);
+
+    end
+endfunction
+
+function string dasm16_2( input[31:0] opcode, input tid=0);
+    case(opcode[15:13])
+    3'b000: return {"c.slli  ", dasm16_ci(opcode)};
+    3'b001: return {"c.fldsp ", dasm16_cls(opcode,1,tid)};
+    3'b010: return {"c.lwsp  ", dasm16_cls(opcode,0,tid)};
+    3'b011: return {"c.flwsp ", dasm16_cls(opcode,0,tid)};
+    3'b101: return {"c.fsdsp ", dasm16_css(opcode,1,tid)};
+    3'b110: return {"c.swsp  ", dasm16_css(opcode,0,tid)};
+    3'b111: return {"c.fswsp ", dasm16_css(opcode,0,tid)};
+    endcase
+    if(opcode[12]) begin
+        if(opcode[12:2] == 0) return "c.ebreak";
+        else if(opcode[6:2] == 0) return $sformatf("c.jalr  %s", abi_reg[opcode[11:7]]);
+        else return $sformatf("c.add   %s,%s", abi_reg[opcode[11:7]], abi_reg[opcode[6:2]]);
+    end
+    else begin
+        if(opcode[6:2] == 0) return $sformatf("c.jr    %s", abi_reg[opcode[11:7]]);
+        else return $sformatf("c.mv    %s,%s", abi_reg[opcode[11:7]], abi_reg[opcode[6:2]]);
+    end
+endfunction
+
+
+function string dasm16_cls( input[31:0] opcode, input sh1=0, tid=0);
+bit[31:0] imm;
+    imm=0;
+    if(sh1) {imm[4:3],imm[8:6]} = opcode[6:2];
+    else    {imm[4:2],imm[7:6]} = opcode[6:2];
+    imm[5] = opcode[12];
+    return $sformatf("%s,0x%0h [%h]", abi_reg[opcode[11:7]], imm, gpr[tid][2]+imm);
+endfunction
+
+function string dasm16_css( input[31:0] opcode, input sh1=0, tid=0);
+bit[31:0] imm;
+    imm=0;
+    if(sh1) {imm[5:3],imm[8:6]} = opcode[12:7];
+    else {imm[5:2],imm[7:6]} = opcode[12:7];
+    return $sformatf("%s,0x%0h [%h]", abi_reg[opcode[6:2]], imm, gpr[tid][2]+imm);
+endfunction
+
+///////////////// 32 bit instructions ///////////////////////
+
+function string dasm32( input[31:0] opcode, input[31:0] pc, input tid=0);
+    case(opcode[6:0])
+    7'b0110111: return {"lui     ", dasm32_u(opcode)};
+    7'b0010111: return {"auipc   ", dasm32_u(opcode)};
+    7'b1101111: return {"jal     ", dasm32_j(opcode,pc)};
+    7'b1100111: return {"jalr    ", dasm32_jr(opcode,pc)};
+    7'b1100011: return dasm32_b(opcode,pc);
+    7'b0000011: return dasm32_l(opcode,tid);
+    7'b0100011: return dasm32_s(opcode,tid);
+    7'b0010011: return dasm32_ai(opcode);
+    7'b0110011: return dasm32_ar(opcode);
+    7'b0001111: return {"fence", dasm32_fence(opcode)};
+    7'b1110011: return dasm32_e(opcode);
+    7'b0101111: return dasm32_a(opcode,tid);
+
+    endcase
+    return $sformatf(".long   0x%h", opcode);
+endfunction
+
+function string dasm32_u( input[31:0] opcode);
+bit[31:0] imm;
+    imm=0;
+    imm[31:12] = opcode[31:12];
+    return $sformatf("%s,0x%0h", abi_reg[opcode[11:7]], imm);
+endfunction
+
+function string dasm32_j( input[31:0] opcode, input[31:0] pc);
+int imm;
+    imm=0;
+    {imm[20], imm[10:1], imm[11], imm[19:12]} = opcode[31:12];
+    if(opcode[31]) imm[31:20] = '1;
+    return $sformatf("%s,0x%0h",abi_reg[opcode[11:7]], imm+pc);
+endfunction
+
+function string dasm32_jr( input[31:0] opcode, input[31:0] pc);
+int imm;
+    imm=0;
+    imm[11:1] = opcode[31:19];
+    if(opcode[31]) imm[31:12] = '1;
+    return $sformatf("%s,%s,0x%0h",abi_reg[opcode[11:7]], abi_reg[opcode[19:15]], imm+pc);
+endfunction
+
+function string dasm32_b( input[31:0] opcode, input[31:0] pc);
+int imm;
+string mn;
+    imm=0;
+    {imm[12],imm[10:5]} = opcode[31:25];
+    {imm[4:1],imm[11]} = opcode[11:7];
+    if(opcode[31]) imm[31:12] = '1;
+    case(opcode[14:12])
+    0: mn = "beq     ";
+    1: mn = "bne     ";
+    2,3 : return $sformatf(".long    0x%h", opcode);
+    4: mn = "blt     ";
+    5: mn = "bge     ";
+    6: mn = "bltu    ";
+    7: mn = "bgeu    ";
+    endcase
+    return $sformatf("%s%s,%s,0x%0h", mn, abi_reg[opcode[19:15]], abi_reg[opcode[24:20]], imm+pc);
+endfunction
+
+function string dasm32_l( input[31:0] opcode, input tid=0);
+int imm;
+string mn;
+    imm=0;
+    imm[11:0] = opcode[31:20];
+    if(opcode[31]) imm[31:12] = '1;
+    case(opcode[14:12])
+    0: mn = "lb      ";
+    1: mn = "lh      ";
+    2: mn = "lw      ";
+    4: mn = "lbu     ";
+    5: mn = "lhu     ";
+    default : return $sformatf(".long   0x%h", opcode);
+    endcase
+    return $sformatf("%s%s,%0d(%s) [%h]", mn, abi_reg[opcode[11:7]], imm, abi_reg[opcode[19:15]], imm+gpr[tid][opcode[19:15]]);
+endfunction
+
+function string dasm32_s( input[31:0] opcode, input tid=0);
+int imm;
+string mn;
+    imm=0;
+    imm[11:5] = opcode[31:25];
+    imm[4:0] = opcode[11:7];
+    if(opcode[31]) imm[31:12] = '1;
+    case(opcode[14:12])
+    0: mn = "sb      ";
+    1: mn = "sh      ";
+    2: mn = "sw      ";
+    default : return $sformatf(".long   0x%h", opcode);
+    endcase
+    return $sformatf("%s%s,%0d(%s) [%h]", mn, abi_reg[opcode[24:20]], imm, abi_reg[opcode[19:15]], imm+gpr[tid][opcode[19:15]]);
+endfunction
+
+function string dasm32_ai( input[31:0] opcode);
+int imm;
+string mn;
+    imm=0;
+    imm[11:0] = opcode[31:20];
+    if(opcode[31]) imm[31:12] = '1;
+    case(opcode[14:12])
+    0: mn = "addi    ";
+    2: mn = "slti    ";
+    3: mn = "sltiu   ";
+    4: mn = "xori    ";
+    6: mn = "ori     ";
+    7: mn = "andi    ";
+    default: return dasm32_si(opcode);
+endcase
+
+return $sformatf("%s%s,%s,%0d", mn, abi_reg[opcode[11:7]], abi_reg[opcode[19:15]], imm);
+endfunction
+
+function string dasm32_si( input[31:0] opcode);
+int imm;
+string mn;
+    imm = opcode[24:20];
+    case(opcode[14:12])
+    1: mn = "slli";
+    5: mn = opcode[30] ? "srli": "srai";
+    endcase
+
+    return $sformatf("%s    %s,%s,%0d", mn, abi_reg[opcode[11:7]], abi_reg[opcode[19:15]], imm);
+endfunction
+
+
+
+function string dasm32_ar( input[31:0] opcode);
+string mn;
+    if(opcode[25])
+        case(opcode[14:12])
+        0: mn = "mul     ";
+        1: mn = "mulh    ";
+        2: mn = "mulhsu  ";
+        3: mn = "mulhu   ";
+        4: mn = "div     ";
+        5: mn = "divu    ";
+        6: mn = "rem     ";
+        7: mn = "remu    ";
+        endcase
+    else
+        case(opcode[14:12])
+        0: mn = opcode[30]? "sub     ":"add     ";
+        1: mn = "sll     ";
+        2: mn = "slt     ";
+        3: mn = "sltu    ";
+        4: mn = "xor     ";
+        5: mn = opcode[30]? "sra     ":"srl     ";
+        6: mn = "or      ";
+        7: mn = "and     ";
+        endcase
+    return $sformatf("%s%s,%s,%s", mn, abi_reg[opcode[11:7]], abi_reg[opcode[19:15]], abi_reg[opcode[24:20]]);
+endfunction
+
+function string dasm32_fence( input[31:0] opcode);
+    return  opcode[12] ? ".i" : "";
+endfunction
+
+function string dasm32_e(input[31:0] opcode);
+    if(opcode[31:7] == 0) return "ecall";
+    else if({opcode[31:21],opcode [19:7]} == 0) return "ebreak";
+    else
+        case(opcode[14:12])
+        1: return {"csrrw   ", dasm32_csr(opcode)};
+        2: return {"csrrs   ", dasm32_csr(opcode)};
+        3: return {"csrrc   ", dasm32_csr(opcode)};
+        5: return {"csrrwi  ", dasm32_csr(opcode, 1)};
+        6: return {"csrrsi  ", dasm32_csr(opcode, 1)};
+        7: return {"csrrci  ", dasm32_csr(opcode, 1)};
+        endcase
+
+endfunction
+
+
+function string dasm32_csr(input[31:0] opcode, input im=0);
+bit[11:0] csr;
+    csr = opcode[31:20];
+    if(im) begin
+        return $sformatf("%s,csr_%0h,0x%h",  abi_reg[opcode[11:7]], csr, opcode[19:15]);
+    end
+    else begin
+        return $sformatf("%s,csr_%0h,%s",  abi_reg[opcode[11:7]], csr, abi_reg[opcode[19:15]]);
+    end
+
+endfunction
+
+//atomics
+function string dasm32_a(input[31:0] opcode, input tid=0);
+    case(opcode[31:27])
+    'b00010: return $sformatf("lr.w    %s,(%s) [%h]",    abi_reg[opcode[11:7]],                         abi_reg[opcode[19:15]], gpr[tid][opcode[19:15]]);
+    'b00011: return $sformatf("sc.w    %s,%s,(%s) [%h]", abi_reg[opcode[11:7]], abi_reg[opcode[24:20]], abi_reg[opcode[19:15]], gpr[tid][opcode[19:15]]);
+    'b00001: return {"amoswap.w", dasm32_amo(opcode, tid)};
+    'b00000: return {"amoadd.w",  dasm32_amo(opcode, tid)};
+    'b00100: return {"amoxor.w",  dasm32_amo(opcode, tid)};
+    'b01100: return {"amoand.w",  dasm32_amo(opcode, tid)};
+    'b01000: return {"amoor.w",   dasm32_amo(opcode, tid)};
+    'b10000: return {"amomin.w",  dasm32_amo(opcode, tid)};
+    'b10100: return {"amomax.w",  dasm32_amo(opcode, tid)};
+    'b11000: return {"amominu.w", dasm32_amo(opcode, tid)};
+    'b11100: return {"amomaxu.w", dasm32_amo(opcode, tid)};
+    endcase
+    return $sformatf(".long 0x%h", opcode);
+endfunction
+
+function string dasm32_amo( input[31:0] opcode, input tid=0);
+    return $sformatf(" %s,%s,(%s) [%h]", abi_reg[opcode[11:7]], abi_reg[opcode[24:20]], abi_reg[opcode[19:15]], gpr[tid][opcode[19:15]]);
+endfunction
diff --git a/test/helloworld/flist b/test/helloworld/flist
new file mode 100644
index 0000000..5e8b8ac
--- /dev/null
+++ b/test/helloworld/flist
@@ -0,0 +1,43 @@
++incdir+$RV_ROOT/testbench
+$RV_ROOT/design/swerv_wrapper.sv
+$RV_ROOT/design/mem.sv
+$RV_ROOT/design/pic_ctrl.sv
+$RV_ROOT/design/swerv.sv
+$RV_ROOT/design/dma_ctrl.sv
+$RV_ROOT/design/ifu/ifu_aln_ctl.sv
+$RV_ROOT/design/ifu/ifu_compress_ctl.sv
+$RV_ROOT/design/ifu/ifu_ifc_ctl.sv
+$RV_ROOT/design/ifu/ifu_bp_ctl.sv
+$RV_ROOT/design/ifu/ifu_ic_mem.sv
+$RV_ROOT/design/ifu/ifu_mem_ctl.sv
+$RV_ROOT/design/ifu/ifu_iccm_mem.sv
+$RV_ROOT/design/ifu/ifu.sv
+$RV_ROOT/design/dec/dec_decode_ctl.sv
+$RV_ROOT/design/dec/dec_gpr_ctl.sv
+$RV_ROOT/design/dec/dec_ib_ctl.sv
+$RV_ROOT/design/dec/dec_tlu_ctl.sv
+$RV_ROOT/design/dec/dec_trigger.sv
+$RV_ROOT/design/dec/dec.sv
+$RV_ROOT/design/exu/exu_alu_ctl.sv
+$RV_ROOT/design/exu/exu_mul_ctl.sv
+$RV_ROOT/design/exu/exu_div_ctl.sv
+$RV_ROOT/design/exu/exu.sv
+$RV_ROOT/design/lsu/lsu.sv
+$RV_ROOT/design/lsu/lsu_clkdomain.sv
+$RV_ROOT/design/lsu/lsu_addrcheck.sv
+$RV_ROOT/design/lsu/lsu_lsc_ctl.sv
+$RV_ROOT/design/lsu/lsu_stbuf.sv
+$RV_ROOT/design/lsu/lsu_bus_buffer.sv
+$RV_ROOT/design/lsu/lsu_bus_intf.sv
+$RV_ROOT/design/lsu/lsu_ecc.sv
+$RV_ROOT/design/lsu/lsu_dccm_mem.sv
+$RV_ROOT/design/lsu/lsu_dccm_ctl.sv
+$RV_ROOT/design/lsu/lsu_trigger.sv
+$RV_ROOT/design/dbg/dbg.sv
+$RV_ROOT/design/dmi/dmi_wrapper.v
+$RV_ROOT/design/dmi/dmi_jtag_to_core_sync.v
+$RV_ROOT/design/dmi/rvjtag_tap.sv
+-v $RV_ROOT/design/lib/beh_lib.sv
+-v $RV_ROOT/design/lib/mem_lib.sv
+-v $RV_ROOT/design/lib/ahb_to_axi4.sv
+-v $RV_ROOT/design/lib/axi4_to_ahb.sv
diff --git a/test/helloworld/hello_world.s b/test/helloworld/hello_world.s
new file mode 100644
index 0000000..92037a1
--- /dev/null
+++ b/test/helloworld/hello_world.s
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2019 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Assembly code for Hello World
+// Not using only ALU ops for creating the string
+
+
+#include "defines.h"
+
+#define STDOUT 0xd0580000
+
+
+// Code to execute
+.section .text
+.global _start
+_start:
+
+    // Clear minstret
+    csrw minstret, zero
+    csrw minstreth, zero
+
+    // Set up MTVEC - not expecting to use it though
+    li x1, RV_ICCM_SADR
+    csrw mtvec, x1
+
+
+    // Enable Caches in MRAC
+    li x1, 0x5f555555
+    csrw 0x7c0, x1
+
+    // Load string from hw_data
+    // and write to stdout address
+
+    li x3, STDOUT
+    la x4, hw_data
+
+loop:
+   lb x5, 0(x4)
+   sb x5, 0(x3)
+   addi x4, x4, 1
+   bnez x5, loop
+
+   li x3, STDOUT
+   la x4, hw_data
+
+loop2:
+   lb x5, 0(x4)
+   sb x5, 0(x3)
+   addi x4, x4, 1
+   bnez x5, loop2
+
+// Write 0xff to STDOUT for TB to terminate test.
+_finish:
+    li x3, STDOUT
+    addi x5, x0, 0xff
+    sb x5, 0(x3)
+    beq x0, x0, _finish
+.rept 100
+    nop
+.endr
+
+.global hw_data
+.data
+hw_data:
+.ascii "----------------------------------\n"
+.ascii "Hello World from Colin EH1 @WDC !!\n"
+.ascii "----------------------------------\n"
+.byte 0
diff --git a/test/helloworld/link.ld b/test/helloworld/link.ld
new file mode 100644
index 0000000..4d50cfe
--- /dev/null
+++ b/test/helloworld/link.ld
@@ -0,0 +1,15 @@
+
+OUTPUT_ARCH( "riscv" )
+ENTRY(_start)
+
+SECTIONS
+{
+    . = 0;
+  .text   : { *(.text*) }
+ _end = .;
+  . = 0x10000;
+  .data  :  ALIGN(0x800) { *(.*data) *(.rodata*) STACK = ALIGN(16) + 0x8000; }
+  .bss : { *(.bss) }
+  . = 0xd0580000;
+  .data.io   : { *(.data.io) }
+}
diff --git a/test/helloworld/swerv.config b/test/helloworld/swerv.config
new file mode 100755
index 0000000..25de140
--- /dev/null
+++ b/test/helloworld/swerv.config
@@ -0,0 +1,2057 @@
+#! /usr/bin/env perl
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2019 Western Digital Corporation or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#use strict;
+use Data::Dumper;
+use Getopt::Long;
+use lib "./";
+use JSON;
+
+my ($self) = $0 =~ m/.*\/(\w+)/o;
+my @argv_orig = @ARGV;
+
+
+# Master configuration file
+#
+# Configuration is perl hash
+# Output are define files for various flows
+#   Verilog (`defines common to RTL/TB)
+#   Software (#defines)
+#   Whisper (JSON/#defines)
+#
+#   Default values and valid ranges should be specified
+#   Can be overridden via the cmd line (-set=name=value-string)
+#
+#  Format of the hash is
+#    name => VALUE | LIST | HASH
+#
+#    Special name "inside" followed by list .. values must be one of provided list
+#    Special name "derive" followed by equation to derive
+#
+
+# Dump verilog/assembly macros in upper case
+my $defines_case = "U";
+
+# Include these macros in verilog (pattern matched)
+my @verilog_vars = qw (xlen reset_vec numiregs nmi_vec protection.* icg target testbench.* dccm.* retstack core.* iccm.* btb.* bht.* icache.* pic.* regwidth memmap bus.*);
+
+# Include these macros in assembly (pattern matched)
+my @asm_vars = qw (xlen reset_vec nmi_vec target dccm.* iccm.* pic.* memmap bus.* testbench.* protection.*);
+my @asm_overridable = qw (reset_vec nmi_vec) ;
+
+# Include these macros in PD (pattern matched)
+my @pd_vars = qw (physical retstack target btb.* bht.* dccm.* iccm.* icache.* pic.* reset_vec nmi_vec build_ahb_lite datawidth bus.*);
+
+# Dump non-derived/settable vars/values for these vars in stdout :
+my @dvars = qw(retstack btb bht core dccm iccm icache pic bus.* reset_vec nmi_vec memmap bus);
+
+
+# Prefix all macros with
+my $prefix = "RV_";
+# No prefix if keyword has
+my $no_prefix = 'RV|TOP|^tec|regwidth|clock_period|assert_on|^datawidth|^physical|verilator|SDVT_AHB';
+
+my $vlog_use__wh = 1;
+
+my %regions_used = ();
+
+# Cmd Line options#{{{
+our %sets;
+our %unsets;
+my $help;
+my @sets = ();
+my @unsets = ();
+
+#Configurations may be changed via the -set option
+#
+#  -set=name=value        : Change the default config parameter value (lowercase)\n";
+#  -unset=name            : Remove the default config parameter (lowercase)\n";
+#                         : Do not prepend RV_ prefex to -set/-unset variables\n";
+#                         : multiple -set/-unset options accepted\n\n";
+#
+
+my $helpusage = "
+
+Main configuration database for SWERV
+
+This script documents, and generates the {`#} define/include files for verilog/assembly/backend flows
+
+
+User options:
+
+     -target = { default, default_ahb, default_pd, high_perf}
+        use default settings for one of the targets
+
+     -set=var=value
+        set arbitrary variable to a value
+     -unset=var
+        unset any definitions for var
+     -snapshot=name
+        name the configuration (only if no -target specified)
+
+Direct options for the following parameters exist:
+
+     -ret_stack_size =      {2, 3, 4, ... 8}
+        size of return stack
+     -btb_size =      { 32, 48, 64, 128, 256, 512 }
+        size of branch target buffer
+     -dccm_region =   { 0x0, 0x1, ... 0xf }
+        number of 256Mb memory region containig DCCM
+     -dccm_offset =   hexadecimal
+        offset (in bytes) of DCCM witin dccm_region
+        dccm address will be: 256M * dccm_region + dccm_offset\", and that must be aligned
+          to the dccm size or the next larger power of 2 if size is not a power of 2
+     -dccm_size   =   { 4, 8, 16, 32, 48, 64, 128, 256, 512 } kB
+        size of DCCM
+     -iccm_enable =   { 0, 1 }
+        whether or not ICCM is enabled
+     -icache_enable = { 0, 1 }
+        whether or not icache is enabled
+     -icache_ecc = { 0, 1 }
+        whether or not icache has ecc - EXPENSIVE 30% sram growth
+        default: icache_ecc==0 (parity)
+     -iccm_region =   { 0x0, 0x1, ... 0xf  }
+        number of 256Mb memory region containing ICCM
+     -iccm_offset =   hexadecimal
+        offcet (in bytes) of ICCM within iccm_region
+        iccm address will be: \"256M * iccm_region + iccm_offset\", and that must be aligned
+          to the iccm size or the next larger power of 2 if size is not a power of 2
+     -iccm_size   =   { 4 , 8 , 16 , 32, 64, 128, 256, 512 } kB
+        size of ICCM
+     -icache_size =   { 16, 32, 64, 128, 256 } kB
+        size of icache
+     -pic_2cycle  =   { 0, 1 }
+        whether or not 2-cycle PIC is enabled (2 cycle pic may result
+        in an overall smaller cycle time)
+     -pic_region =    { 0x0, 0x1, ... 0xf  }
+         nuber of 256Mb memory region containing PIC memory-mapped registers
+     -pic_offset =    hexadecial
+         offset (in bytes) of PIC within pic_region
+         pic address will be: \"256M * pic_region + pic_offset\", and that must be aligned
+          to the pic size or the next larger power of 2 if size is not a power of 2
+     -pic_size   =    { 32, 64, 128, 256 } kB
+         size of PIC
+     -pic_total_int = { 1, 2, 3, ..., 255 }
+         number of interrupt sources in PIC
+     -ahb_lite
+         build with AHB-lite bus interface
+         default is AXI4
+     -fpga_optimize =   { 0, 1 }
+        if 1, minimize clock-gating to facilitate FPGA builds
+";
+
+
+my $ret_stack_size;
+my $btb_size;
+my $bht_size;
+my $dccm_region;
+my $dccm_offset;
+my $dccm_size;
+my $iccm_enable;
+my $icache_enable;
+my $icache_ecc;
+my $iccm_region;
+my $iccm_offset;
+my $iccm_size;
+my $icache_size;
+my $pic_2cycle;
+my $pic_region;
+my $pic_offset;
+my $pic_size;
+my $pic_total_int;
+my $ahb_lite;
+my $fpga_optimize;
+
+my $top_align_iccm = 0;
+
+my $target = "default";
+my $snapshot ;
+my $build_path ;
+
+GetOptions(
+    "help"              => \$help,
+    "target=s"          => \$target,
+    "snapshot=s"        => \$snapshot,
+    "verbose"           => \$verbose,
+    "ret_stack_size=s"  => \$ret_stack_size,
+    "btb_size=s"        => \$btb_size,
+    "bht_size=s"        => \$bht_size,
+    "dccm_enable=s"     => \$dccm_enable,
+    "dccm_region=s"     => \$dccm_region,
+    "dccm_offset=s"     => \$dccm_offset,
+    "dccm_size=s"       => \$dccm_size,
+    "iccm_enable=s"     => \$iccm_enable,
+    "icache_enable=s"   => \$icache_enable,
+    "icache_ecc=s"      => \$icache_ecc,
+    "iccm_region=s"     => \$iccm_region,
+    "iccm_offset=s"     => \$iccm_offset,
+    "iccm_size=s"       => \$iccm_size,
+    "pic_2cycle=s"      => \$pic_2cycle,
+    "pic_region=s"      => \$pic_region,
+    "pic_offset=s"      => \$pic_offset,
+    "pic_size=s"        => \$pic_size,
+    "pic_total_int=s"   => \$pic_total_int,
+    "icache_size=s"     => \$icache_size,
+    "ahb_lite"          => \$ahb_lite,
+    "fpga_optimize"     => \$fpga_optimize,
+    "set=s@"            => \@sets,
+    "unset=s@"          => \@unsets,
+) || die("$helpusage");
+
+if ($help) {
+   print "$helpusage\n";
+   exit;
+}
+
+if (!defined $snapshot ) {
+    $snapshot = $target;
+}
+
+if (!defined $ENV{BUILD_PATH}) {
+    $build_path = "$ENV{PWD}/snapshots/$snapshot" ;
+} else {
+    $build_path = $ENV{BUILD_PATH};
+}
+
+if (! -d "$build_path") {
+    system ("mkdir -p $build_path");
+}
+
+# Verilog defines file path
+my $vlogfile = "$build_path/common_defines.vh";
+
+# Assembly defines file path
+my $asmfile = "$build_path/defines.h";
+
+# PD defines file path
+my $pdfile = "$build_path/pd_defines.vh";
+
+# Whisper config file path
+my $whisperfile = "$build_path/whisper.json";
+
+# Default linker file
+my $linkerfile = "$build_path/link.ld";
+
+# Perl defines file path
+my $perlfile = "$build_path/perl_configs.pl";
+
+my $no_secondary_alu=0;
+
+if ($target eq "default") {
+    if (!defined($ret_stack_size))    { $ret_stack_size=4; }
+    if (!defined($btb_size))          { $btb_size=32; }
+    if (!defined($bht_size))          { $bht_size=128; }
+    if (!defined($dccm_enable))       { $dccm_enable=1; }
+    if (!defined($dccm_region))       { $dccm_region="0xf"; }
+    if (!defined($dccm_offset))       { $dccm_offset="0x40000"; } #1*256*1024
+    if (!defined($dccm_size))         { $dccm_size=64; }
+    if (!defined($dccm_num_banks))    { $dccm_num_banks=8; }
+    if (!defined($iccm_enable))       { $iccm_enable=0; }
+    if (!defined($iccm_region))       { $iccm_region="0xe"; }
+    if (!defined($iccm_offset))       { $iccm_offset="0xe000000"; } #0x380*256*1024
+    if (!defined($iccm_size))         { $iccm_size=512; }
+    if (!defined($iccm_num_banks))    { $iccm_num_banks=8; }
+    if (!defined($icache_enable))     { $icache_enable=1; }
+    if (!defined($icache_ecc))        { $icache_ecc=0; }
+    if (!defined($icache_size))       { $icache_size=16; }
+    if (!defined($pic_2cycle))        { $pic_2cycle=0; }
+    if (!defined($pic_region))        { $pic_region="0xf"; }
+    if (!defined($pic_offset))        { $pic_offset="0xc0000"; } # 3*256*1024
+    if (!defined($pic_size))          { $pic_size=32; }
+    if (!defined($pic_total_int))     { $pic_total_int=8; }
+    if (!defined($fpga_optimize))     { $fpga_optimize=1; }
+
+    # default is AXI bus
+}
+elsif ($target eq "default_ahb") {
+    if (!defined($ret_stack_size))    { $ret_stack_size=4; }
+    if (!defined($btb_size))          { $btb_size=32; }
+    if (!defined($bht_size))          { $bht_size=128; }
+    if (!defined($dccm_enable))       { $dccm_enable=1; }
+    if (!defined($dccm_region))       { $dccm_region="0xf"; }
+    if (!defined($dccm_offset))       { $dccm_offset="0x40000"; } #1*256*1024
+    if (!defined($dccm_size))         { $dccm_size=64; }
+    if (!defined($dccm_num_banks))    { $dccm_num_banks=8; }
+    if (!defined($iccm_enable))       { $iccm_enable=0; }
+    if (!defined($iccm_region))       { $iccm_region="0xe"; }
+    if (!defined($iccm_offset))       { $iccm_offset="0xe000000"; } #0x380*256*1024
+    if (!defined($iccm_size))         { $iccm_size=512; }
+    if (!defined($iccm_num_banks))    { $iccm_num_banks=8; }
+    if (!defined($icache_enable))     { $icache_enable=1; }
+    if (!defined($icache_ecc))        { $icache_ecc=0; }
+    if (!defined($icache_size))       { $icache_size=16; }
+    if (!defined($pic_2cycle))        { $pic_2cycle=0; }
+    if (!defined($pic_region))        { $pic_region="0xf"; }
+    if (!defined($pic_offset))        { $pic_offset="0xc0000"; } # 3*256*1024
+    if (!defined($pic_size))          { $pic_size=32; }
+    if (!defined($pic_total_int))     { $pic_total_int=8; }
+    if (!defined($fpga_optimize))     { $fpga_optimize=1; }
+    $ahb_lite = 1;
+
+} elsif ($target eq "default_pd") {
+    if (!defined($ret_stack_size))    { $ret_stack_size=4; }
+    if (!defined($btb_size))          { $btb_size=32; }
+    if (!defined($bht_size))          { $bht_size=128; }
+    if (!defined($dccm_enable))       { $dccm_enable=1; }
+    if (!defined($dccm_region))       { $dccm_region="0xf"; }
+    if (!defined($dccm_offset))       { $dccm_offset="0x40000"; } #1*256*1024
+    if (!defined($dccm_size))         { $dccm_size=32; }
+    if (!defined($dccm_num_banks))    { $dccm_num_banks=8; }
+    if (!defined($iccm_enable))       { $iccm_enable=0; }
+    if (!defined($iccm_region))       { $iccm_region="0xe"; }
+    if (!defined($iccm_offset))       { $iccm_offset="0xe000000"; } #0x380*256*1024
+    if (!defined($iccm_size))         { $iccm_size=512; }
+    if (!defined($iccm_num_banks))    { $iccm_num_banks=8; }
+    if (!defined($icache_enable))     { $icache_enable=1; }
+    if (!defined($icache_ecc))        { $icache_ecc=0; }
+    if (!defined($icache_size))       { $icache_size=16; }
+    if (!defined($pic_2cycle))        { $pic_2cycle=0; }
+    if (!defined($pic_region))        { $pic_region="0xf"; }
+    if (!defined($pic_offset))        { $pic_offset="0xc0000"; } # 3*256*1024
+    if (!defined($pic_size))          { $pic_size=32; }
+    if (!defined($pic_total_int))     { $pic_total_int=8; }
+    if (!defined($fpga_optimize))     { $fpga_optimize=0; }
+
+} elsif ($target eq "high_perf") {
+    if (!defined($ret_stack_size))    { $ret_stack_size=4; }
+    if (!defined($btb_size))          { $btb_size=512; }
+    if (!defined($bht_size))          { $bht_size=2048; }
+    if (!defined($dccm_enable))       { $dccm_enable=1; }
+    if (!defined($dccm_region))       { $dccm_region="0xf"; }
+    if (!defined($dccm_offset))       { $dccm_offset="0x40000"; } #1*256*1024
+    if (!defined($dccm_size))         { $dccm_size=64; }
+    if (!defined($dccm_num_banks))    { $dccm_num_banks=8; }
+    if (!defined($iccm_enable))       { $iccm_enable=0; }
+    if (!defined($iccm_region))       { $iccm_region="0xe"; }
+    if (!defined($iccm_offset))       { $iccm_offset="0xe000000"; } #0x380*256*1024
+    if (!defined($iccm_size))         { $iccm_size=512; }
+    if (!defined($iccm_num_banks))    { $iccm_num_banks=8; }
+    if (!defined($icache_enable))     { $icache_enable=1; }
+    if (!defined($icache_ecc))        { $icache_ecc=0; }
+    if (!defined($icache_size))       { $icache_size=32; }
+    if (!defined($pic_2cycle))        { $pic_2cycle=0; }
+    if (!defined($pic_region))        { $pic_region="0xf"; }
+    if (!defined($pic_offset))        { $pic_offset="0xc0000"; } # 3*256*1024
+    if (!defined($pic_size))          { $pic_size=32; }
+    if (!defined($pic_total_int))     { $pic_total_int=8; }
+    if (!defined($fpga_optimize))     { $fpga_optimize=1; }
+
+} else {
+    die "$self: ERROR! Unsupported target \"$target\". Supported targets are: \"default, default_ahb, default_pd, high_perf\"!\n";
+}
+
+# general stuff - can't set from command line other than -set
+
+if (!defined($lsu_stbuf_depth))   { $lsu_stbuf_depth=8;   }
+if (!defined($dma_buf_depth))     { $dma_buf_depth=4;     }
+if (!defined($lsu_num_nbload))    { $lsu_num_nbload=8;   }
+if (!defined($dec_instbuf_depth)) { $dec_instbuf_depth=4; }
+
+
+# Configure triggers
+our @triggers = (#{{{
+    {
+        "reset"         => ["0x23e00000", "0x00000000", "0x00000000"],
+        "mask"          => ["0x081818c7", "0xffffffff", "0x00000000"],
+        "poke_mask"     => ["0x081818c7", "0xffffffff", "0x00000000"]
+    },
+    {
+        "reset"         => ["0x23e00000", "0x00000000", "0x00000000"],
+        "mask"          => ["0x081810c7", "0xffffffff", "0x00000000"],
+        "poke_mask"     => ["0x081810c7", "0xffffffff", "0x00000000"]
+    },
+    {
+        "reset"         => ["0x23e00000", "0x00000000", "0x00000000"],
+        "mask"          => ["0x081818c7", "0xffffffff", "0x00000000"],
+        "poke_mask"     => ["0x081818c7", "0xffffffff", "0x00000000"]
+    },
+    {
+        "reset"         => ["0x23e00000", "0x00000000", "0x00000000"],
+        "mask"          => ["0x081810c7", "0xffffffff", "0x00000000"],
+        "poke_mask"     => ["0x081810c7", "0xffffffff", "0x00000000"]
+    },
+ );#}}}
+
+
+# Configure CSRs
+our %csr = (#{{{
+    "mstatus" => {
+       "reset"         => "0x1800", # MPP bits hard wired to binrary 11.
+       "mask"          => "0x88",   # Only mpie(7) & mie(3) bits writeable
+       "exists"        => "true",
+    },
+    "mie" => {
+        "reset"         => "0x0",
+        # Only external, timer, local, and software writeable
+        "mask"          => "0x70000888",
+        "exists"        => "true",
+    },
+    "mip" => {
+        "reset"         => "0x0",
+        # None of the bits are writeable using CSR instructions
+        "mask"          => "0x0",
+        # Bits corresponding to error overflow, external, timer and stoftware
+        # interrupts are modifiable
+        "poke_mask"     => "0x70000888",
+        "exists"        => "true",
+    },
+   "mvendorid" => {
+       "reset"         => "0x45",
+       "mask"          => "0x0",
+       "exists"        => "true",
+   },
+   "marchid" => {
+       "reset"         => "0x0000000b",
+       "mask"          => "0x0",
+       "exists"        => "true",
+   },
+   "mimpid" => {
+       "reset"         => "0x6",
+       "mask"          => "0x0",
+       "exists"        => "true",
+   },
+   "misa" => {
+       "reset"         => "0x40001104",
+       "mask"          => "0x0",
+       "exists"        => "true",
+   },
+   "tselect" => {
+       "reset"         => "0x0",
+       "mask"          => "0x3",    # Four triggers
+       "exists"        => "true",
+   },
+   "dcsr" => {
+       "reset"         => "0x40000003",
+       "mask"          => "0x00008c04",
+       "poke_mask"     => "0x00008dcc",  # cause field modifiable, nmip modifiable
+       "exists"        => "true",
+    },
+    "cycle" => {
+        "exists"       => "false",
+    },
+    "time" => {
+        "exists"       => "false",
+    },
+    "instret" => {
+        "exists"       => "false",
+    },
+    "mcountinhibit" => {
+       "exists"        => "false",
+    },
+    "mcounteren" => {
+       "exists"        => "false",
+    },
+    "mhpmcounter3" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter4" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter5" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter6" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter3h" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter4h" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter5h" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmcounter6h" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmevent3" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmevent4" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmevent5" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mhpmevent6" => {
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+# Remaining CSRs are non-standard. These are specific to SWERV
+    "dicawics" => {
+       "number"        => "0x7c8",
+       "reset"         => "0x0",
+       "mask"          => "0x0130fffc",
+       "exists"        => "true",
+    },
+    "dicad0" => {
+       "number"        => "0x7c9",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "dicad1" => {
+       "number"        => "0x7ca",
+       "reset"         => "0x0",
+       "mask"          => "0x3",
+       "exists"        => "true",
+    },
+    "dicago" => {
+       "number"        => "0x7cb",
+       "reset"         => "0x0",
+       "mask"          => "0x0",
+       "exists"        => "true",
+    },
+    "mgpmc" => {
+       "number"        => "0x7d0",
+       "reset"         => "0x1",
+       "mask"          => "0x1",
+       "exists"        => "true",
+    },
+    "mitcnt0" => {
+       "number"        => "0x7d2",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mitbnd0" => {
+       "number"        => "0x7d3",
+       "reset"         => "0xffffffff",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mitctl0" => {
+       "number"        => "0x7d4",
+       "reset"         => "0x1",
+       "mask"          => "0x00000007",
+       "exists"        => "true",
+    },
+    "mitcnt1" => {
+       "number"        => "0x7d5",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mitbnd1" => {
+       "number"        => "0x7d6",
+       "reset"         => "0xffffffff",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mitctl1" => {
+       "number"        => "0x7d7",
+       "reset"         => "0x1",
+       "mask"          => "0x00000007",
+       "exists"        => "true",
+    },
+    "mcpc" => {
+       "number"        => "0x7c2",
+       "reset"         => "0x0",
+       "mask"          => "0x0",
+       "exists"        => "true",
+    },
+    "mpmc" => {
+       "comment"       => "FWHALT",
+       "number"        => "0x7c6",
+       "reset"         => "0x2",
+       "mask"          => "0x2",
+       "poke_mask"     => "0x2",
+       "exists"        => "true",
+    },
+    "micect" => {
+       "number"        => "0x7f0",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "miccmect" => {
+       "number"        => "0x7f1",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mdccmect" => {
+       "number"        => "0x7f2",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+    },
+    "mcgc" => {
+       "number"        => "0x7f8",
+       "reset"         => "0x0",
+       "mask"          => "0x000001ff",
+       "poke_mask"     => "0x000001ff",
+       "exists"        => "true",
+    },
+    "mfdc" => {
+       "number"        => "0x7f9",
+       "reset"         => "0x00070000",
+       "mask"          => "0x000727ff",
+       "exists"        => "true",
+    },
+    "dmst" => {
+       "comment"       => "Memory synch trigger: Flush caches in debug mode.",
+       "number"        => "0x7c4",
+       "reset"         => "0x0",
+       "mask"          => "0x0",
+       "exists"        => "true",
+       "debug"         => "true",
+    },
+    "dicawics" => {
+       "comment"       => "Cache diagnostics.",
+       "number"        => "0x7c8",
+       "reset"         => "0x0",
+       "mask"          => "0x0130fffc",
+       "exists"        => "true",
+       "debug"         => "true",
+    },
+    "dicad0" => {
+       "comment"       => "Cache diagnostics.",
+       "number"        => "0x7c9",
+       "reset"         => "0x0",
+       "mask"          => "0xffffffff",
+       "exists"        => "true",
+       "debug"         => "true",
+    },
+    "dicad1" => {
+       "comment"       => "Cache diagnostics.",
+       "number"        => "0x7ca",
+       "reset"         => "0x0",
+       "mask"          => "0x3",
+       "exists"        => "true",
+       "debug"         => "true",
+    },
+    "dicago" => {
+       "comment"       => "Cache diagnostics.",
+       "number"        => "0x7cb",
+       "reset"         => "0x0",
+       "mask"          => "0x0",
+       "exists"        => "true",
+       "debug"         => "true",
+    },
+    "meipt" => {
+       "comment"       => "External interrupt priority threshold.",
+       "number"        => "0xbc9",
+       "reset"         => "0x0",
+       "mask"          => "0xf",
+       "exists"        => "true",
+    },
+    "meicpct" => {
+       "comment"       => "External claim id/priority capture.",
+       "number"        => "0xbca",
+       "reset"         => "0x0",
+       "mask"          => "0x0",
+       "exists"        => "true",
+    },
+    "meicidpl" => {
+       "comment"       => "External interrupt claim id priority level.",
+       "number"        => "0xbcb",
+       "reset"         => "0x0",
+       "mask"          => "0xf",
+       "exists"        => "true",
+    },
+    "meicurpl" => {
+       "comment"       => "External interrupt current priority level.",
+       "number"        => "0xbcc",
+       "reset"         => "0x0",
+       "mask"          => "0xf",
+       "exists"        => "true",
+    },
+
+);#}}}
+
+
+foreach my $i (0 .. 3) {
+    $csr{"pmpcfg$i"} = { "exists" => "false" };
+}
+
+foreach my $i (0 .. 15) {
+    $csr{"pmpaddr$i"} = { "exists" => "false" };
+}
+
+
+
+# }}}
+# Main config hash, with default values
+#
+# Hash can be hierarchical with arbitrary levels
+# Hexadecimal values are prefixed with 0x
+#
+# For verilog, if bit width is expected, add to %width hash below
+our %config = (#{{{
+    "harts"                 => "1",
+    "xlen"                  => "32",
+    "numiregs"              => "32",
+    "regwidth"              => "32",
+    "reset_vec"             => "0x80000000",
+    "nmi_vec"               => "0x11110000",
+    "physical"              => "1",
+    "num_mmode_perf_regs"   => "4",   # Whisper only
+    "max_mmode_perf_event"  => "50",  # Whisper only: performance counters event ids will be clamped to this
+    "target"                => $target,
+    "tec_rv_icg"            => "clockhdr",
+        "verilator"          => "$verilator",
+
+    "retstack" => {
+            "ret_stack_size"    => "$ret_stack_size",
+    },
+
+    "btb"  => {
+         "btb_size"         => "$btb_size",
+         "btb_index1_hi"    => "derived",
+         "btb_index1_lo"    => "4",
+         "btb_index2_hi"    => "derived",
+         "btb_index2_lo"    => "derived",
+         "btb_index3_hi"    => "derived",
+         "btb_index3_lo"    => "derived",
+         "btb_addr_hi"      => "derived",
+         "btb_array_depth"  => "derived",
+         "btb_addr_lo"      => "4",
+         "btb_btag_size"    => "derived",
+    },
+    "bht"  => {
+         "bht_size"         => "$bht_size",
+         "bht_addr_hi"      => "derived",
+         "bht_addr_lo"      => "4",
+         "bht_array_depth"  => "derived",
+         "bht_ghr_size"     => "derived",
+         "bht_ghr_range"    => "derived",
+         "bht_ghr_pad"      => "derived",
+         "bht_ghr_pad2"     => "derived",
+         "bht_hash_string"  => "derived",
+
+    },
+
+    "core" => {
+        "dec_instbuf_depth" => "$dec_instbuf_depth",
+        "lsu_stbuf_depth"   => "$lsu_stbuf_depth",
+        "dma_buf_depth"     => "$dma_buf_depth",
+        "lsu_num_nbload"    => "$lsu_num_nbload",
+        "no_secondary_alu"  => "$no_secondary_alu",
+        "fpga_optimize"     => "$fpga_optimize"
+    },
+
+    "dccm" => {
+        "dccm_enable"       => "$dccm_enable",                          # Comment this out if no DCCM
+        "dccm_region"       => "$dccm_region",                       # 256M region number
+        "dccm_offset"       => "$dccm_offset",                         # 256K offset number
+        "dccm_size"         => "$dccm_size",                       # Size in Kbytes
+        "dccm_num_banks"    => "$dccm_num_banks",
+        "dccm_sadr"         => 'derived',
+        "dccm_eadr"         => 'derived',
+         "dccm_bits"         => 'derived',
+        "dccm_bank_bits"         => 'derived',
+        "dccm_data_width"         => 'derived',
+        "dccm_fdata_width"         => 'derived',
+        "dccm_byte_width"         => 'derived',
+        "dccm_width_bits"         => 'derived',
+        "dccm_index_bits"         => 'derived',
+        "dccm_ecc_width"         => 'derived',
+        "lsu_sb_bits"         => 'derived',
+        "dccm_data_cell"     => 'derived',
+        "dccm_rows"          => 'derived',
+        "dccm_reserved"     => 'derived',                                  # reserve dccm space for SW/stack - no random r/w
+    },
+
+
+    "iccm" => {
+        "iccm_enable"       => "$iccm_enable",                          # Comment this out if no ICCM
+        "iccm_region"       => "$iccm_region",                       # 256M region number
+        "iccm_offset"       => "$iccm_offset",                     # 256K offset number
+        "iccm_size"         => "$iccm_size",                       # Size in Kbytes
+        "iccm_num_banks"    => "$iccm_num_banks",
+        "iccm_bank_bits"    => 'derived',
+        "iccm_index_bits"   => 'derived',
+        "iccm_rows"         => 'derived',
+        "iccm_data_cell"    => 'derived',
+        "iccm_sadr"         => 'derived',
+        "iccm_eadr"         => 'derived',
+        "iccm_reserved"     => 'derived',                                  # reserve iccm space for SW/handlers - no random r/w
+    },
+    "icache" => {
+        "icache_enable"     => "$icache_enable",
+        "icache_size"       => "$icache_size",
+        "icache_data_cell"  => 'derived',
+        "icache_tag_cell"   => 'derived',
+        "icache_taddr_high" => 'derived',
+        "icache_tag_high"   => 'derived',
+        "icache_tag_depth"  => 'derived',
+        "icache_ic_depth"   => 'derived',
+        "icache_ic_rows"    => 'derived',
+        "icache_ic_index"    => 'derived',
+        "icache_tag_low"    => '6',
+        "icache_ecc"        => "$icache_ecc",
+    },
+    "pic" => {
+        "pic_2cycle"         => "$pic_2cycle",   # two cycle PIC for timing reasons
+        "pic_region"         => "$pic_region",   # 256M region number
+        "pic_offset"         => "$pic_offset",   # 256K offset number
+        "pic_size"           => "$pic_size",     # Size in Kbytes
+        "pic_base_addr"      => 'derived', # base_addr = pic_region + offset
+        "pic_total_int_plus1"      => 'derived', # pic_total_int + 1
+        "pic_total_int"      => "$pic_total_int",# number of interrupt pins (Smax)
+        "pic_int_words"      => 'derived', # number of 32 bit words for packed registers (Xmax)
+        "pic_bits"           => 'derived', # of bits needs to address the PICM
+        "pic_meipl_offset"   => '0x0000',        # Offset of meipl relative to pic_base_addr
+        "pic_meip_offset"    => '0x1000',        # Offset of meip relative to pic_base_addr
+        "pic_meie_offset"    => '0x2000',        # Offset of meie relative to pic_base_addr
+        "pic_mpiccfg_offset" => '0x3000',        # Offset of mpiccfg relative to pic_base_addr
+        "pic_meipt_offset"   => '0x3004',        # Offset of meipt relative to pic_base_addr -- deprecated
+        "pic_meigwctrl_offset" => '0x4000',      # gateway control regs relative to pic_base_addr
+        "pic_meigwclr_offset"  => '0x5000',       # gateway clear regs relative to pic_base_addr
+  "pic_meipl_mask"     => '0xf',
+        "pic_meip_mask"      => '0x0',
+        "pic_meie_mask"      => '0x1',
+        "pic_mpiccfg_mask"   => '0x1',
+        "pic_meipt_mask"     => '0x0',
+        "pic_meigwctrl_mask" => '0x3',
+        "pic_meigwclr_mask"  => '0x0',
+
+        "pic_meipl_count"     => $pic_total_int,
+        "pic_meip_count"      => 4,
+        "pic_meie_count"      => $pic_total_int,
+        "pic_mpiccfg_count"   => 1,
+        "pic_meipt_count"     => $pic_total_int,
+        "pic_meigwctrl_count" => $pic_total_int,
+        "pic_meigwclr_count"  => $pic_total_int
+    },
+    "testbench" => {
+        "TOP"               => "tb_top",
+        "RV_TOP"            => "`TOP.rvtop",
+        "CPU_TOP"            => "`RV_TOP.swerv",
+        "clock_period"      => "100",
+        "build_ahb_lite"    => "$ahb_lite",       # one and only one bus build arg will ever be defined
+        "build_axi4"        => "1",
+        "assert_on"         => "",
+        "datawidth"         => "64",                        # deprecate this !! FIXME
+        "ext_datawidth"     => "64",
+        "ext_addrwidth"     => "32",
+        "sterr_rollback"    => "0",
+        "lderr_rollback"    => "1",
+        "SDVT_AHB"          => "1",
+    },
+   "protection" => {
+        "inst_access_enable0" => "0x0",
+        "inst_access_addr0"   => "0x00000000",
+        "inst_access_mask0"   => "0xffffffff",
+        "inst_access_enable1" => "0x0",
+        "inst_access_addr1"   => "0x00000000",
+        "inst_access_mask1"   => "0xffffffff",
+        "inst_access_enable2" => "0x0",
+        "inst_access_addr2"   => "0x00000000",
+        "inst_access_mask2"   => "0xffffffff",
+        "inst_access_enable3" => "0x0",
+        "inst_access_addr3"   => "0x00000000",
+        "inst_access_mask3"   => "0xffffffff",
+        "inst_access_enable4" => "0x0",
+        "inst_access_addr4"   => "0x00000000",
+        "inst_access_mask4"   => "0xffffffff",
+        "inst_access_enable5" => "0x0",
+        "inst_access_addr5"   => "0x00000000",
+        "inst_access_mask5"   => "0xffffffff",
+        "inst_access_enable6" => "0x0",
+        "inst_access_addr6"   => "0x00000000",
+        "inst_access_mask6"   => "0xffffffff",
+        "inst_access_enable7" => "0x0",
+        "inst_access_addr7"   => "0x00000000",
+        "inst_access_mask7"   => "0xffffffff",
+        "data_access_enable0" => "0x0",
+        "data_access_addr0"   => "0x00000000",
+        "data_access_mask0"   => "0xffffffff",
+        "data_access_enable1" => "0x0",
+        "data_access_addr1"   => "0x00000000",
+        "data_access_mask1"   => "0xffffffff",
+        "data_access_enable2" => "0x0",
+        "data_access_addr2"   => "0x00000000",
+        "data_access_mask2"   => "0xffffffff",
+        "data_access_enable3" => "0x0",
+        "data_access_addr3"   => "0x00000000",
+        "data_access_mask3"   => "0xffffffff",
+        "data_access_enable4" => "0x0",
+        "data_access_addr4"   => "0x00000000",
+        "data_access_mask4"   => "0xffffffff",
+        "data_access_enable5" => "0x0",
+        "data_access_addr5"   => "0x00000000",
+        "data_access_mask5"   => "0xffffffff",
+        "data_access_enable6" => "0x0",
+        "data_access_addr6"   => "0x00000000",
+        "data_access_mask6"   => "0xffffffff",
+        "data_access_enable7" => "0x0",
+        "data_access_addr7"   => "0x00000000",
+        "data_access_mask7"   => "0xffffffff",
+     },
+    "memmap" => {                                                       # Testbench only
+        "serialio"          => 'derived, overridable',                  # Testbench only
+        "external_data"     => 'derived, overridable',                  # Testbench only
+        "external_prog"     => 'derived, overridable',                  # Testbench only
+        "debug_sb_mem"      => 'derived, overridable',                  # Testbench only
+        "external_data_1"   => 'derived, overridable',                  # Testbench only
+        "external_mem_hole"   => 'default disabled',                    # Testbench only
+#       "consoleio"         => 'derived',   # Part of serial io.
+    },
+    "bus" => {
+        "lsu_bus_tag"      => 'derived',
+        "dma_bus_tag"      => '1',
+        "sb_bus_tag"       => '1',
+        "ifu_bus_tag"      => '3',
+    },
+    "triggers" => \@triggers,
+    "csr" => \%csr,
+    "even_odd_trigger_chains" => "true",
+);
+
+if (($fpga_optimize==0) && !grep(/fpga_optimize/, @sets)) { delete $config{"core"}{"fpga_optimize"}; }
+if (($iccm_enable==0) && !grep(/iccm_enable/, @sets)) { delete $config{"iccm"}{"iccm_enable"}; }
+if (($dccm_enable==0) && !grep(/dccm_enable/, @sets)) { delete $config{"dccm"}{"dccm_enable"}; }
+if (($icache_enable==0) && !grep(/icache_enable/, @sets)) { delete $config{"icache"}{"icache_enable"}; }
+if (($verilator==0) && !grep(/verilator/, @sets))     { delete $config{"core"}{"verilator"}; }
+if (($no_secondary_alu==0) && !grep(/no_secondary_alu/, @sets))           { delete $config{"core"}{"no_secondary_alu"}; }
+if (($pic_2cycle==0) && !grep(/pic_2cycle/, @sets)) { delete $config{"pic"}{"pic_2cycle"}; }
+if (($icache_ecc==0) && !grep(/icache_ecc/, @sets)) { delete $config{"icache"}{"icache_ecc"}; }
+
+
+
+# Perform any overrides first before derived values
+map_set_unset();
+gen_define("","", \%config,[]);
+print "\nSweRV configuration for target=$target\n\n";
+dump_define("","", \%config,[]);
+
+
+# perform final checks
+my $c;
+$c=$config{retstack}{ret_stack_size}; if (!($c >=2 && $c <=8))                                 { die("$helpusage\n\nFAIL: ret_stack_size == $c;   ILLEGAL !!!\n\n"); }
+$c=$config{btb}{btb_size};            if (!($c==32||$c==48||$c==64||$c==128||$c==256||$c==512)){ die("$helpusage\n\nFAIL: btb_size == $c;         ILLEGAL !!!\n\n"); }
+$c=$config{iccm}{iccm_region};        if (!($c>=0 && $c<16))                                   { die("$helpusage\n\nFAIL: iccm_region == $c       ILLEGAL !!!\n\n"); }
+$c=$config{iccm}{iccm_offset};        if (!($c>=0  && $c<256*1024*1024 && ($c&0xfff)==0))      { die("$helpusage\n\nFAIL: iccm_offset == $c       ILLEGAL !!!\n\n"); }
+$c=$config{iccm}{iccm_size};          if (!($c==4||$c==8||$c==16||$c==32||$c==64||$c==128||$c==256||$c==512)) { die("$helpusage\n\nFAIL: iccm_size == $c         ILLEGAL !!!\n\n"); }
+$c=$config{iccm}{iccm_num_banks};     if (!($c==4 || $c==8  || ($c==16 && $config{iccm}{iccm_size} != 4)))    { die("$helpusage\n\nFAIL: iccm_num_banks == $c    ILLEGAL !!!\n\n"); }
+$c=$config{iccm}{iccm_enable};        if (!($c==0  || $c==1))                                  { die("$helpusage\n\nFAIL: iccm_enable == $c       ILLEGAL !!!\n\n"); }
+$c=$config{dccm}{dccm_region};        if (!($c>=0  && $c<16))                                  { die("$helpusage\n\nFAIL: iccm_region == $c       ILLEGAL !!!\n\n"); }
+$c=$config{dccm}{dccm_num_banks};     if (!($c==4 || $c==8 || ($c==16 && $config{dccm}{dccm_size} != 4) ))                                   { die("$helpusage\n\nFAIL: dccm_num_banks == $c    ILLEGAL !!!\n\n"); }
+$c=$config{dccm}{dccm_offset};        if (!($c>=0  && $c<256*1024*1024 && ($c&0xfff)==0))      { die("$helpusage\n\nFAIL: iccm_offset == $c       ILLEGAL !!!\n\n"); }
+$c=$config{dccm}{dccm_size};          if (!($c==4||$c==8||$c==16||$c==32||$c==48||$c==64||$c==128||$c==256||$c==512))        { die("$helpusage\n\nFAIL: iccm_size == $c         ILLEGAL !!!\n\n"); }
+$c=$config{pic}{pic_2cycle};          if (!($c==0  || $c==1))                                  { die("$helpusage\n\nFAIL: pic_2cycle == $c        ILLEGAL !!!\n\n"); }
+$c=$config{pic}{pic_region};          if (!($c>=0 && $c<16))                                   { die("$helpusage\n\nFAIL: pic_region == $c        ILLEGAL !!!\n\n"); }
+$c=$config{pic}{pic_offset};          if (!($c>=0  && $c<256*1024*1024 && ($c&0xfff)==0))      { die("$helpusage\n\nFAIL: pic_offset == $c        ILLEGAL !!!\n\n"); }
+$c=$config{pic}{pic_size};            if (!($c==32 || $c==64 || $c==128 || $c==256))           { die("$helpusage\n\nFAIL: pic_size == $c          ILLEGAL !!!\n\n"); }
+$c=$config{pic}{pic_total_int};       if (  $c<1 || $c>255)                                    { die("$helpusage\n\nFAIL: pic_total_int == $c     ILLEGAL !!!\n\n"); }
+$c=$config{icache}{icache_enable};    if (!($c==0 || $c==1))                                   { die("$helpusage\n\nFAIL: icache_enable == $c     ILLEGAL !!!\n\n"); }
+$c=$config{icache}{icache_size};      if (!($c==16 || $c==32 || $c==64 || $c==128 || $c==256)) { die("$helpusage\n\nFAIL: icache_size == $c       ILLEGAL !!!\n\n"); }
+$c=$config{core}{dec_instbuf_depth};  if (!($c==2 || $c==4))                                   { die("$helpusage\n\nFAIL: dec_instbuf_depth == $c ILLEGAL !!!\n\n"); }
+$c=$config{core}{lsu_stbuf_depth};    if (!($c==2 || $c==4 || $c==8))                          { die("$helpusage\n\nFAIL: lsu_stbuf_depth == $c   ILLEGAL !!!\n\n"); }
+$c=$config{core}{dma_buf_depth};      if (!($c==2 || $c==4))                                   { die("$helpusage\n\nFAIL: dma_buf_depth == $c     ILLEGAL !!!\n\n"); }
+$c=$config{core}{lsu_num_nbload};     if (!($c==2 || $c==4 || $c==8))                          { die("$helpusage\n\nFAIL: lsu_num_nbload == $c   ILLEGAL !!!\n\n"); }
+
+$c=$config{protection}{inst_access_addr0}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr0 lower 6b must be 0s $c !!!\n\n"); }
+$c=$config{protection}{inst_access_addr1}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr1 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr2}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr2 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr3}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr3 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr4}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr4 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr5}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr5 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr6}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr6 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_addr7}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: inst_access_addr7 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask0}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask0 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask1}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask1 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask2}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask2 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask3}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask3 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask4}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask4 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask5}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask5 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask6}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask6 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{inst_access_mask7}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: inst_access_mask7 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_addr0}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr0 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr1}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr1 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr2}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr2 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr3}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr3 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr4}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr4 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr5}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr5 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr6}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr6 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_addr7}; if ((hex($c)&0x3f) != 0)                                { die("$helpusage\n\nFAIL: data_access_addr7 lower 6b must be 0s !!!\n\n"); }
+$c=$config{protection}{data_access_mask0}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask0 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask1}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask1 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask2}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask2 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask3}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask3 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask4}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask4 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask5}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask5 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask6}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask6 lower 6b must be 1s !!!\n\n"); }
+$c=$config{protection}{data_access_mask7}; if ((hex($c)&0x3f) != 63)                               { die("$helpusage\n\nFAIL: data_access_mask7 lower 6b must be 1s !!!\n\n"); }
+
+
+
+if (($config{testbench}{build_ahb_lite} ne "")) {
+    delete $config{testbench}{build_axi4};
+}
+else {  # default is AXI bus
+    delete $config{testbench}{build_ahb_lite};
+}
+
+
+# Over-ride MFDC reset value for AXI.
+if (exists($config{testbench}{build_axi4}) ) {
+    $config{csr}{mfdc}{reset} = "0x00070040" if exists $config{csr}{mfdc};
+}
+
+
+
+# Fill in derived configuration entries.
+
+if($config{btb}{btb_size}==512){
+    $config{btb}{btb_index1_hi} = 9;
+    $config{btb}{btb_index2_hi} = 15;
+    $config{btb}{btb_index3_hi} = 21;
+    $config{btb}{btb_array_depth}= 64;
+    $config{btb}{btb_btag_size} = 5;
+} elsif($config{btb}{btb_size}==256){
+    $config{btb}{btb_index1_hi} = 8;
+    $config{btb}{btb_index2_hi} = 13;
+    $config{btb}{btb_index3_hi} = 18;
+    $config{btb}{btb_array_depth}= 32;
+    $config{btb}{btb_btag_size} = 6;
+} elsif($config{btb}{btb_size}==128){
+    $config{btb}{btb_index1_hi} = 7;
+    $config{btb}{btb_index2_hi} = 11;
+    $config{btb}{btb_index3_hi} = 15;
+    $config{btb}{btb_array_depth}= 16;
+    $config{btb}{btb_btag_size} = 7;
+} elsif($config{btb}{btb_size}==64){
+    $config{btb}{btb_index1_hi} = 6;
+    $config{btb}{btb_index2_hi} = 9;
+    $config{btb}{btb_index3_hi} = 12;
+    $config{btb}{btb_array_depth}= 8;
+    $config{btb}{btb_btag_size} = 8;
+} elsif($config{btb}{btb_size}==48){
+    $config{btb}{btb_index1_hi} = 5;
+    $config{btb}{btb_index2_hi} = 7;
+    $config{btb}{btb_index3_hi} = 9;
+    $config{btb}{btb_array_depth}= 4;
+    $config{btb}{btb_48}= 1;
+    $config{btb}{btb_fold2_index_hash} = 1;
+    $config{btb}{btb_btag_size} = 9;
+    $config{btb}{btb_btag_fold} = 1;
+} elsif($config{btb}{btb_size}==32){
+    $config{btb}{btb_index1_hi} = 5;
+    $config{btb}{btb_index2_hi} = 7;
+    $config{btb}{btb_index3_hi} = 9;
+    $config{btb}{btb_array_depth}= 4;
+    $config{btb}{btb_btag_size} = 9;
+    $config{btb}{btb_btag_fold} = 1;
+}
+
+$config{btb}{btb_index2_lo} = $config{btb}{btb_index1_hi}+1;
+$config{btb}{btb_index3_lo} = $config{btb}{btb_index2_hi}+1;
+$config{btb}{btb_addr_hi}   = $config{btb}{btb_index1_hi};
+
+# BHT index is a hash of the GHR and PC_HASH
+sub ghrhash{
+    my($btb_index_hi,$ghr_size) = @_;
+
+    $btb_addr_width = $btb_index_hi - 3;
+
+    $ghr_hi = $ghr_size - 1;
+    $ghr_lo = $btb_addr_width;
+
+    $ghr_start = "{";
+    if($ghr_size > $btb_addr_width){
+        if($ghr_size-1 == $btb_addr_width){
+            $string= "{ghr[$ghr_hi:$ghr_lo] ^ ghr[$ghr_hi+1],hashin[$config{btb}{btb_index1_hi}:4]^ghr[$ghr_lo-1:0]}";
+        }
+        else{
+            $string = "{ghr[$ghr_hi:$ghr_lo] ^ {ghr[$ghr_hi+1], {$ghr_size-1-$btb_addr_width\{1'b0} } },hashin[$config{btb}{btb_index1_hi}:4]^ghr[$ghr_lo-1:0]}";
+        }
+    }
+    elsif($ghr_size < $btb_addr_width){
+        $string = "{hashin[$ghr_size+3:4]^ghr[$ghr_size-1:0]^{ghr[$ghr_hi+1], {$ghr_hi\{1'b0} } }}";
+    }
+    else{ $string = "{hashin[$config{btb}{btb_index1_hi}:4]^ghr[$ghr_lo-1:0]^{ghr[$ghr_hi+1], {$btb_addr_width-1\{1'b0} } } }"}
+    return $string;
+
+}
+
+
+if($config{bht}{bht_size}==2048){
+    $config{bht}{bht_ghr_size}= 9;
+    $config{bht}{bht_ghr_range}= "8:0";
+    $config{bht}{bht_ghr_pad}= "fghr[8:4],3'b0";
+    $config{bht}{bht_ghr_pad2}= "fghr[8:3],2'b0";
+    $config{bht}{bht_array_depth}= 256;
+    $config{bht}{bht_addr_hi}= 11;
+} elsif($config{bht}{bht_size}==1024){
+    $config{bht}{bht_ghr_size}= 8;
+    $config{bht}{bht_ghr_range}= "7:0";
+    $config{bht}{bht_ghr_pad}= "fghr[7:4],3'b0";
+    $config{bht}{bht_ghr_pad2}= "fghr[7:3],2'b0";
+    $config{bht}{bht_array_depth}= 128;
+    $config{bht}{bht_addr_hi}= 10;
+} elsif($config{bht}{bht_size}==512){
+    $config{bht}{bht_ghr_size}= 7;
+    $config{bht}{bht_ghr_range}= "6:0";
+    $config{bht}{bht_ghr_pad}= "fghr[6:4],3'b0";
+    $config{bht}{bht_ghr_pad2}= "fghr[6:3],2'b0";
+    $config{bht}{bht_array_depth}= 64;
+    $config{bht}{bht_addr_hi}= 9;
+} elsif($config{bht}{bht_size}==256){
+    $config{bht}{bht_ghr_size}= 6;
+    $config{bht}{bht_ghr_range}= "5:0";
+    $config{bht}{bht_ghr_pad}= "fghr[5:4],3'b0";
+    $config{bht}{bht_ghr_pad2}= "fghr[5:3],2'b0";
+    $config{bht}{bht_addr_hi} = 8;
+    $config{bht}{bht_array_depth}= 32;
+} elsif($config{bht}{bht_size}==128){
+    $config{bht}{bht_ghr_size}= 5;
+    $config{bht}{bht_ghr_range}= "4:0";
+    $config{bht}{bht_ghr_pad}= "fghr[4],3'b0";
+    $config{bht}{bht_ghr_pad2}= "fghr[4:3],2'b0";
+    $config{bht}{bht_addr_hi} = 7;
+    $config{bht}{bht_array_depth}= 16;
+} elsif($config{bht}{bht_size}==64){
+    $config{bht}{bht_ghr_size}= 4;
+    $config{bht}{bht_ghr_range}= "3:0";
+    $config{bht}{bht_ghr_pad}= "3'b0 ";
+    $config{bht}{bht_ghr_pad2}= "fghr[3],2'b0";
+    $config{bht}{bht_addr_hi} = 6;
+    $config{bht}{bht_array_depth}= 8;
+} elsif($config{bht}{bht_size}==32){
+    $config{bht}{bht_ghr_size}= 3;
+    $config{bht}{bht_ghr_range}= "2:0";
+    $config{bht}{bht_ghr_pad}= "2'b0 ";
+    $config{bht}{bht_ghr_pad2}= "2'b0";
+    $config{bht}{bht_addr_hi} = 5;
+    $config{bht}{bht_array_depth}= 4;
+}
+
+$config{bht}{bht_hash_string} = &ghrhash($config{btb}{btb_index1_hi}, $config{bht}{bht_ghr_size}-1);
+
+$config{pic}{pic_base_addr} = (hex($config{pic}{pic_region})<<28) +
+    (hex($config{pic}{pic_offset}));
+$config{pic}{pic_base_addr} = sprintf("0x%x", $config{pic}{pic_base_addr});
+
+$config{pic}{pic_int_words} = int($config{pic}{pic_total_int}/32 +0.9);
+$config{pic}{pic_bits} = 10 + log2($config{pic}{pic_size});
+
+$config{core}{lsu_num_nbload_width} = log2($config{core}{lsu_num_nbload});
+
+$config{bus}{lsu_bus_tag} = log2($config{core}{lsu_num_nbload}) + 1;
+
+$config{dccm}{dccm_sadr} = (hex($config{dccm}{dccm_region})<<28) +
+    (hex($config{dccm}{dccm_offset}));
+$config{dccm}{dccm_sadr} = sprintf("0x%x", $config{dccm}{dccm_sadr});
+
+$config{dccm}{dccm_eadr} = (hex($config{dccm}{dccm_region})<<28) +
+    (hex($config{dccm}{dccm_offset})) + size($config{dccm}{dccm_size})-1;
+$config{dccm}{dccm_eadr} = sprintf("0x%x", $config{dccm}{dccm_eadr});
+
+$config{dccm}{dccm_reserved} = sprintf("0x%x", ($config{dccm}{dccm_size}>30)? 4096 : ($config{dccm}{dccm_size}*1024)/4);
+
+$config{dccm}{dccm_bits} =  ($config{dccm}{dccm_size}==48 ) ? 16 : 10 + log2($config{dccm}{dccm_size});
+
+$config{dccm}{dccm_bank_bits} = log2($config{dccm}{dccm_num_banks});
+$config{dccm}{dccm_data_width} = 32;
+$config{dccm}{dccm_fdata_width} = $config{dccm}{dccm_data_width} + log2($config{dccm}{dccm_data_width}) + 2;
+$config{dccm}{dccm_byte_width} = $config{dccm}{dccm_data_width}/8;
+
+$config{dccm}{dccm_width_bits} = log2($config{dccm}{dccm_byte_width});
+$config{dccm}{dccm_index_bits} = $config{dccm}{dccm_bits} - $config{dccm}{dccm_bank_bits} - $config{dccm}{dccm_width_bits};
+
+$config{dccm}{dccm_ecc_width} = log2($config{dccm}{dccm_data_width}) + 2;
+$config{dccm}{lsu_sb_bits}    = (($config{dccm}{dccm_bits}) > ($config{pic}{pic_bits})) ? ($config{dccm}{dccm_bits}) : ($config{pic}{pic_bits});
+$config{dccm}{dccm_rows}      = ($config{dccm}{dccm_size}==48 ) ? (2**($config{dccm}{dccm_index_bits}-1) +  2**$config{dccm}{dccm_index_bits})/2   : 2**$config{dccm}{dccm_index_bits};
+$config{dccm}{dccm_data_cell} = "ram_$config{dccm}{dccm_rows}x39";
+
+
+$config{icache}{icache_tag_high} = (($config{icache}{icache_size}==256) ? 16 :
+                                    ($config{icache}{icache_size}==128) ? 15 :
+                                    ($config{icache}{icache_size}==64)  ? 14 :
+                                    ($config{icache}{icache_size}==32)  ? 13 : 12);
+
+$config{icache}{icache_tag_depth} = (($config{icache}{icache_size}==256) ? 1024 :
+                                    ($config{icache}{icache_size}==128) ? 512 :
+                                    ($config{icache}{icache_size}==64)  ? 256 :
+                                    ($config{icache}{icache_size}==32)  ? 128 : 64);
+
+
+$config{icache}{icache_ic_depth} =  log2($config{icache}{icache_size}) + 4;
+$config{icache}{icache_ic_index} =  log2($config{icache}{icache_size}) + 4;
+$config{icache}{icache_ic_rows}  =  2**$config{icache}{icache_ic_depth};
+
+
+$config{icache}{icache_taddr_high} = log2($config{icache}{icache_tag_depth}) - 1;
+
+if (defined($config{icache}{icache_ecc})) {
+$config{icache}{icache_data_cell}   = "ram_$config{icache}{icache_ic_rows}x42";
+$config{icache}{icache_tag_cell}    = "ram_$config{icache}{icache_tag_depth}x25";
+
+}
+else {
+$config{icache}{icache_data_cell}   = "ram_$config{icache}{icache_ic_rows}x34";
+$config{icache}{icache_tag_cell}    = "ram_$config{icache}{icache_tag_depth}x21";
+}
+$config{pic}{pic_total_int_plus1} = $config{pic}{pic_total_int} + 1;
+# Defines with explicit values in the macro name
+$config{dccm}{"dccm_num_banks_$config{dccm}{dccm_num_banks}"} = "";
+$config{dccm}{"dccm_size_$config{dccm}{dccm_size}"} = "";
+
+# If ICCM offset not explicitly provided, align to TOP of the region
+if ($top_align_iccm && ($config{iccm}{iccm_offset} eq $iccm_offset) && ($config{iccm}{iccm_size} < 32)) {
+    $config{iccm}{iccm_region} = "0xa";
+    print "$self: Setting default iccm region to region $config{iccm}{iccm_region}\n";
+    $config{iccm}{iccm_offset} = sprintf("0x%08x",256*1024*1024-size($config{iccm}{iccm_size}));
+    print "$self: Aligning default iccm offset to top of region @ $config{iccm}{iccm_offset}\n";
+}
+$config{iccm}{iccm_sadr} = (hex($config{iccm}{iccm_region})<<28) +
+                           (hex($config{iccm}{iccm_offset}));
+$config{iccm}{iccm_sadr} = sprintf("0x%08x", $config{iccm}{iccm_sadr});
+
+$config{iccm}{iccm_eadr} = (hex($config{iccm}{iccm_region})<<28) +
+                           (hex($config{iccm}{iccm_offset})) + size($config{iccm}{iccm_size})-1;
+$config{iccm}{iccm_eadr} = sprintf("0x%08x", $config{iccm}{iccm_eadr});
+
+$config{iccm}{iccm_reserved} = sprintf("0x%x", ($config{iccm}{iccm_size}>30)? 4096 : ($config{iccm}{iccm_size}*1024)/4);
+
+$config{iccm}{iccm_bits}      = 10 + log2($config{iccm}{iccm_size});
+$config{iccm}{iccm_bank_bits} = log2($config{iccm}{iccm_num_banks});  //-1;
+$config{iccm}{iccm_index_bits} = $config{iccm}{iccm_bits} - $config{iccm}{iccm_bank_bits} - 2;   # always 4 bytes
+$config{iccm}{iccm_rows}      = 2**$config{iccm}{iccm_index_bits};
+$config{iccm}{iccm_data_cell} = "ram_$config{iccm}{iccm_rows}x39";
+# Defines with explicit values in the macro name
+$config{iccm}{"iccm_num_banks_$config{iccm}{iccm_num_banks}"} = "";
+$config{iccm}{"iccm_size_$config{iccm}{iccm_size}"} = "";
+
+delete $config{core}{fpga_optimize} if ($config{core}{fpga_optimize} == 0);
+
+# Track used regions
+
+$regions_used{hex($config{iccm}{iccm_region})} = 1;
+$regions_used{hex($config{dccm}{dccm_region})} = 1;
+$regions_used{hex($config{pic}{pic_region})} = 1;
+$regions_used{hex($config{reset_vec})>>28} = 1;
+
+# Find an unused region for serial IO
+for (my $rgn = 15;$rgn >= 0; $rgn--) {
+    if (($rgn != hex($config{iccm}{iccm_region})) &&
+        ($rgn != hex($config{dccm}{dccm_region})) &&
+        ($rgn != (hex($config{pic}{pic_region})))) {
+        $config{memmap}{serialio} = ($rgn << 28) + (22<<18);
+        $regions_used{$rgn} = 1;
+        last;
+    }
+}
+
+$config{memmap}{serialio} = sprintf("0x%08x", $config{memmap}{serialio});
+
+# Find an unused region for external data
+for (my $rgn = 15;$rgn >= 0; $rgn--) {
+    if (($rgn != hex($config{iccm}{iccm_region})) &&
+        ($rgn != hex($config{dccm}{dccm_region})) &&
+        ($rgn != (hex($config{memmap}{serialio})>>28)) &&
+        ($rgn != (hex($config{pic}{pic_region})))) {
+        $config{memmap}{external_data} = ($rgn << 28) + (22<<18);
+        $regions_used{$rgn} = 1;
+        last;
+    }
+}
+$config{memmap}{external_data} = sprintf("0x%08x", $config{memmap}{external_data});
+#
+# Find an unused region for external prog
+for (my $rgn = 15;$rgn >= 0; $rgn--) {
+    if (($rgn != hex($config{iccm}{iccm_region})) &&
+        ($rgn != hex($config{dccm}{dccm_region})) &&
+        ($rgn != (hex($config{memmap}{serialio})>>28)) &&
+        ($rgn != (hex($config{memmap}{external_data})>>28)) &&
+        ($rgn != (hex($config{pic}{pic_region})))) {
+        $config{memmap}{external_prog} = ($rgn << 28);
+        $regions_used{$rgn} = 1;
+        last;
+    }
+}
+$config{memmap}{external_prog} = sprintf("0x%08x", $config{memmap}{external_prog});
+
+# Unused region for second data
+for (my $rgn = 15;$rgn >= 0; $rgn--) {
+    if (($rgn != hex($config{iccm}{iccm_region})) &&
+        ($rgn != hex($config{dccm}{dccm_region})) &&
+        ($rgn != (hex($config{memmap}{serialio})>>28)) &&
+        ($rgn != (hex($config{memmap}{external_data})>>28)) &&
+        ($rgn != (hex($config{memmap}{external_prog})>>28)  &&
+        ($rgn != (hex($config{pic}{pic_region})))
+        )) {
+        $config{memmap}{external_data_1} = ($rgn << 28);
+        $regions_used{$rgn} = 1;
+        last;
+    }
+}
+$config{memmap}{external_data_1} = sprintf("0x%08x", $config{memmap}{data_1});
+
+
+#$config{memmap}{consoleio} = hex($config{memmap}{serialio}) + 0x100;
+#$config{memmap}{consoleio} = sprintf("0x%x", $config{memmap}{consoleio});
+
+# Find an unused region for debug_sb_memory data
+for (my $rgn = 15;$rgn >= 0; $rgn--) {
+    if (($rgn != hex($config{iccm}{iccm_region})) &&
+        ($rgn != hex($config{dccm}{dccm_region})) &&
+        ($rgn != (hex($config{memmap}{serialio})>>28)) &&
+        ($rgn != (hex($config{memmap}{external_data})>>28)) &&
+        ($rgn != (hex($config{memmap}{external_data_1})>>28)) &&
+        ($rgn != (hex($config{pic}{pic_region})))) {
+        $config{memmap}{debug_sb_mem} = ($rgn << 28) + (22<<18);
+        $regions_used{$rgn} = 1;
+        last;
+    }
+}
+$config{memmap}{debug_sb_mem} = sprintf("0x%08x", $config{memmap}{debug_sb_mem});
+
+
+# Create the memory map hole for random testing
+# Only do this if masks are not enabled already
+if (hex($config{protection}{data_access_enable0}) > 0 ||
+    hex($config{protection}{data_access_enable1}) > 0 ||
+    hex($config{protection}{data_access_enable2}) > 0 ||
+    hex($config{protection}{data_access_enable3}) > 0 ||
+    hex($config{protection}{data_access_enable4}) > 0 ||
+    hex($config{protection}{data_access_enable5}) > 0 ||
+    hex($config{protection}{data_access_enable6}) > 0 ||
+    hex($config{protection}{data_access_enable7}) > 0 ||
+    hex($config{protection}{inst_access_enable0}) > 0 ||
+    hex($config{protection}{inst_access_enable1}) > 0 ||
+    hex($config{protection}{inst_access_enable2}) > 0 ||
+    hex($config{protection}{inst_access_enable3}) > 0 ||
+    hex($config{protection}{inst_access_enable4}) > 0 ||
+    hex($config{protection}{inst_access_enable5}) > 0 ||
+    hex($config{protection}{inst_access_enable6}) > 0 ||
+    hex($config{protection}{inst_access_enable7}) > 0 ||
+    $config{memmap}{external_mem_hole} eq "default disabled"){
+    delete($config{memmap}{external_mem_hole}) ;
+} else {
+    # Unused region to create a memory map hole, if not already specified
+    if ($config{memmap}{external_mem_hole} eq "derived, overridable") {
+        for (my $rgn = 15;$rgn >= 0; $rgn--) {
+            if (!defined($regions_used{$rgn})) {
+                $config{memmap}{external_mem_hole} = ($rgn << 28);
+                $regions_used{$rgn} = 1;
+                last;
+            }
+        }
+    } else {
+        my $rgn = hex($config{memmap}{external_mem_hole})>>28;
+        $config{memmap}{external_mem_hole} = ($rgn << 28);
+        $regions_used{$rgn} =1;
+    }
+    my $hreg = $config{memmap}{external_mem_hole}>>28;
+    $config{protection}{data_access_addr0} = sprintf("0x%x", (($hreg^8)&8)<<28);
+    $config{protection}{data_access_mask0} = "0x7fffffff";
+    $config{protection}{data_access_addr1} = sprintf("0x%x", ($hreg&8) << 28 |(($hreg^4)&4)<<28);
+    $config{protection}{data_access_mask1} = "0x3fffffff";
+    $config{protection}{data_access_addr2} = sprintf("0x%x", ($hreg&12) <<28 | (($hreg^2)&2) <<28);
+    $config{protection}{data_access_mask2} = "0x1fffffff";
+    $config{protection}{data_access_addr3} = sprintf("0x%x", ($hreg&14) << 28 |(($hreg^1)&1)<<28);
+    $config{protection}{data_access_mask3} = "0x0fffffff";
+    $config{protection}{data_access_enable0} = "1";
+    $config{protection}{data_access_enable1} = "1";
+    $config{protection}{data_access_enable2} = "1";
+    $config{protection}{data_access_enable3} = "1";
+    $config{protection}{inst_access_addr0} = sprintf("0x%x", (($hreg^8)&8)<<28);
+    $config{protection}{inst_access_mask0} = "0x7fffffff";
+    $config{protection}{inst_access_addr1} = sprintf("0x%x", ($hreg&8) << 28 |(($hreg^4)&4)<<28);
+    $config{protection}{inst_access_mask1} = "0x3fffffff";
+    $config{protection}{inst_access_addr2} = sprintf("0x%x", ($hreg&12) <<28 | (($hreg^2)&2) <<28);
+    $config{protection}{inst_access_mask2} = "0x1fffffff";
+    $config{protection}{inst_access_addr3} = sprintf("0x%x", ($hreg&14) << 28 |(($hreg^1)&1)<<28);
+    $config{protection}{inst_access_mask3} = "0x0fffffff";
+    $config{protection}{inst_access_enable0} = "1";
+    $config{protection}{inst_access_enable1} = "1";
+    $config{protection}{inst_access_enable2} = "1";
+    $config{protection}{inst_access_enable3} = "1";
+
+    $config{memmap}{external_mem_hole} = sprintf("0x%08x", $config{memmap}{external_mem_hole});
+}
+
+
+#Define 5 unused regions for used in TG
+
+foreach my $unr (reverse(0 .. 15)) {
+    if (!defined($regions_used{$unr})) {
+        $config{memmap}{"unused_region$unr"} = sprintf("0x%08x",($unr << 28));
+        $regions_used{$unr} = 1;
+    }
+}
+
+if ($target eq "baseline") {
+    $config{reset_vec} = $config{iccm}{iccm_sadr};
+    $config{testbench}{magellan} = 1;
+    print "$self: Setting reset_vec = ICCM start address for Baseline\n";
+}
+
+
+# Output bit-width specifiers for these variables
+our %widths = (
+        "dccm_region"   => "4",
+        "dccm_offset"   => "28",
+        "dccm_sadr"     => "32",
+        "dccm_eadr"     => "32",
+        "pic_region"    => "4",
+        "pic_offset"    => "10",
+        "pic_base_addr" => "32",
+        "iccm_region"   => "4",
+        "iccm_offset"   => "10",
+        "iccm_sadr"     => "32",
+        "iccm_eadr"     => "32",
+        "bus_prty_default" => "2",
+        "inst_access_enable0" => "1",
+        "inst_access_enable1" => "1",
+        "inst_access_enable2" => "1",
+        "inst_access_enable3" => "1",
+        "inst_access_enable4" => "1",
+        "inst_access_enable5" => "1",
+        "inst_access_enable6" => "1",
+        "inst_access_enable7" => "1",
+        "data_access_enable0" => "1",
+        "data_access_enable1" => "1",
+        "data_access_enable2" => "1",
+        "data_access_enable3" => "1",
+        "data_access_enable4" => "1",
+        "data_access_enable5" => "1",
+        "data_access_enable6" => "1",
+        "data_access_enable7" => "1",
+);
+#}}}
+
+
+#-----------------------Reset Vector MPU check-----------------------#
+$flag_pass=0;
+if(!(hex($config{reset_vec}) >= ((hex($config{iccm}{iccm_region})<<28) + (hex($config{iccm}{iccm_offset}))) && (hex($config{reset_vec}) < ((hex($config{iccm}{iccm_region})<<28) + (hex($config{iccm}{iccm_offset})) + size($config{iccm}{iccm_size})-1))))
+{
+    for(my $i=0; $i<8; $i++)
+    {
+        $inst_access_enable = "inst_access_enable$i";
+        $inst_access_addr = "inst_access_addr$i";
+        $inst_access_mask = "inst_access_mask$i";
+        if(hex($config{protection}{$inst_access_enable}))
+        {
+                if((hex($config{reset_vec})>= hex($config{protection}{$inst_access_addr})) && (hex($config{reset_vec})< (hex($config{protection}{$inst_access_addr}) | hex($config{protection}{$inst_access_mask}))))
+                {
+                        $flag_pass++;
+                        last;
+                }
+        }
+        else    {$enable_check++;}
+    }
+
+if($flag_pass == 0 & $enable_check < 8)  {      die("$helpusage\n\nFAIL: RESET_VECTOR not in any of MPU enabled instruction access windows or ICCM !!!\n\n");}
+}
+#-----------------------Reset Vector MPU check-----------------------#
+
+#print Dumper(\%config);
+#print Dumper(\%width);
+
+#print Dumper(\%sets);
+#print Dumper(\%unsets);
+
+# Sanity checks
+check_addr_align("dccm", hex($config{dccm}{dccm_sadr}), $config{dccm}{dccm_size}*1024);
+check_addr_align("iccm", hex($config{iccm}{iccm_sadr}), $config{iccm}{iccm_size}*1024);
+check_addr_align("pic", hex($config{pic}{pic_base_addr}), $config{pic}{pic_size}*1024);
+
+#   Prevent overlap of internal memories
+if ((hex($config{pic}{pic_region}) == hex($config{iccm}{iccm_region})) && (hex($config{pic}{pic_offset}) == hex($config{iccm}{iccm_offset}))) {
+    die "$self: ERROR! PIC and ICCM blocks collide (region $config{iccm}{iccm_region}, offset $config{pic}{pic_offset})!\n";
+}
+if ((hex($config{pic}{pic_region}) == hex($config{dccm}{dccm_region})) && (hex($config{pic}{pic_offset}) == hex($config{dccm}{dccm_offset}))) {
+    die "$self: ERROR! PIC and DCCM blocks collide (region $config{dccm}{dccm_region}, offset $config{pic}{pic_offset})!\n";
+}
+if ((hex($config{iccm}{iccm_region}) == hex($config{dccm}{dccm_region})) && (hex($config{iccm}{iccm_offset}) == hex($config{dccm}{dccm_offset}))) {
+    die "$self: ERROR! ICCM and DCCM blocks collide (region $config{iccm}{iccm_region}, offset $config{dccm}{dccm_offset})!\n";
+}
+
+##################### Add dumper routines here ##########################
+#
+# Dump Verilog $RV_ROOT/configs/common_defines.vh
+print "$self: Writing $vlogfile\n";
+open (FILE, ">$vlogfile") || die "Cannot open $vlogfile for writing $!\n";
+print_header("//");
+gen_define("","`", \%config, \@verilog_vars);
+close FILE;
+
+print "$self: Writing $asmfile\n";
+open (FILE, ">$asmfile") || die "Cannot open $asmfile for writing $!\n";
+# Dump ASM/C   $RV_ROOT/diags/env/defines.h
+print_header("//");
+gen_define("","#", \%config, \@asm_vars, \@asm_overridable);
+close FILE;
+
+# add `define PHYSICAL 1
+# remove `undef RV_ICCM_ENABLE
+
+my $pddata='
+`include "common_defines.vh"
+`undef ASSERT_ON
+`undef TEC_RV_ICG
+`define TEC_RV_ICG CKLNQD12BWP35P140
+`define PHYSICAL 1
+';
+
+
+print "$self: Writing $pdfile\n";
+open (FILE, ">$pdfile") || die "Cannot open $pdfile for writing $!\n";
+# Dump PD   $RV_ROOT/$RV_ROOT/configs/pd_defines.vh
+print_header("//");
+printf (FILE "$pddata");
+close FILE;
+
+print "$self: Writing $whisperfile\n";
+dump_whisper_config(\%config, $whisperfile);
+
+
+# change this to use config version
+#`$ENV{RV_ROOT}/tools/picmap -t $config{pic}{pic_total_int} > $ENV{RV_ROOT}/design/include/pic_map_auto.h`;
+`$ENV{RV_ROOT}/tools/picmap -t $config{pic}{pic_total_int} > $build_path/pic_map_auto.h`;
+#`$ENV{RV_ROOT}/tools/unrollforverilator  $config{pic}{pic_total_int_plus1} > $ENV{RV_ROOT}/design/include/pic_ctrl_verilator_unroll.sv`;
+`$ENV{RV_ROOT}/tools/unrollforverilator  $config{pic}{pic_total_int_plus1} > $build_path/pic_ctrl_verilator_unroll.sv`;
+
+# Perl vars for use by scripts
+print "$self: Writing $perlfile\n";
+open (FILE, ">$perlfile") || die "Cannot open $perlfile for writing $!\n";
+print_header("# ");
+print FILE "# To use this in a perf script, use 'require \$RV_ROOT/configs/config.pl'\n";
+print FILE "# Reference the hash via \$config{name}..\n\n\n";
+print FILE Data::Dumper->Dump([\%config], [ qw(*config) ]);
+print FILE "1;\n";
+close FILE;
+
+# Default linker script
+gen_default_linker_script();
+# Done ##################################################################
+#
+exit(0);
+
+# ######################   Helper subroutines ##########################{{{
+# Convert size in kilobytes to real value
+
+sub size {#{{{
+    my $ksize = shift;
+    my $size = sprintf("%d",$ksize*1024);
+    return $size;
+}#}}}
+
+# Print the defines with prefix
+sub print_define {#{{{
+    my ($sym, $key,$value, $override) = @_;
+    my $lprefix = $prefix if ($key !~ /$no_prefix/);
+    if ($sym eq "`") {
+        if (defined($widths{$key})) {
+            $value =~ s/^(0x)*/$widths{$key}'h/;
+        } else {
+            $value =~ s/^0x/'h/;
+        }
+    }
+    if ($defines_case eq "U") {
+        print FILE "${sym}ifndef \U$lprefix$key\E\n" if ($override);
+        print FILE "${sym}define \U$lprefix$key\E $value\n";
+        print FILE "${sym}endif\n" if ($override);
+    } else {
+        print FILE "${sym}ifndef $lprefix$key\n" if ($override);
+        print FILE "${sym}define $lprefix$key $value\n";
+        print FILE "${sym}endif\n" if ($override);
+    }
+}#}}}
+
+# print header
+sub print_header {#{{{
+    my $cs = shift;
+    print FILE "$cs NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE\n";
+    print FILE "$cs This is an automatically generated file by $ENV{USER} on ",`date`;
+    print FILE "$cs\n$cs cmd:    $self @argv_orig \n";
+    print FILE "$cs\n";
+}#}}}
+
+# evaluate derivations
+sub derive {#{{{
+    my $eqn = shift;
+    return sprintf("0x%x", eval($eqn));
+}#}}}
+
+# traverse the database and extract the key/value pair
+sub gen_define {#{{{
+    my $matched = shift;
+    my $prefix = shift;
+    my $hash = @_[0];
+    my @printvars = @{@_[1]};
+    my @overridable = @{@_[2]};
+    my $re = join("|",@printvars);
+    $re = qr/($re)/;
+    #print Dumper($hash);
+    foreach my $key (keys %$hash) {
+        next if $key eq "csr";
+        #print "looking at $key:$matched ($re)\n";
+        if (defined($unsets{$key})) {
+            print "$self:unsetting $key\n";
+            delete($config{$key});
+            next
+        }
+        if (defined($sets{$key}) && $sets{$key} ne $$hash{$key}) {
+            if (($$hash{$key} =~ /derived/i) && ($$hash{$key} !~ /overridable/i)) {
+                die ("$self: ERROR! $key is a derived and non-overridable parameter!\n");
+            } else {
+                print "$self: Overriding $key value $$hash{$key} with $sets{$key}\n";
+                $$hash{$key} = $sets{$key};
+            }
+        }
+        my $value = $$hash{$key};
+        if (ref($value) eq "HASH") {
+            if ($key =~ /$re/) {
+                $matched = 1;
+            }
+            gen_define($matched,$prefix, $value, \@printvars, \@overridable);
+            $matched = 0;
+        } elsif (ref($value) eq "ARRAY") {
+            # print "$key : @{$value}\n";
+             $matched = 0;
+        } else {
+            if ($matched eq "1" || $key =~ /$re/) {
+                if($value =~ /derive\(.*\)/o) {
+                    $value = eval($value);
+                }
+                $override = grep(/^$key$/, @overridable);
+                    print_define($prefix, $key, $value, $override);
+            }
+        }
+    }
+}#}}}
+
+sub dump_define {#{{{
+    my $matched = shift;
+    my $prefix = shift;
+    my $hash = @_[0];
+    my @printvars = @{@_[1]};
+    my @overridable = @{@_[2]};
+    my $re = join("|",@printvars);
+    $re = qr/($re)/;
+    #print Dumper($hash);
+    foreach my $key (keys %$hash) {
+        next if $key eq "csr";
+        next unless $matched || grep(/^$key$/,@dvars);
+        #print "looking at $key:$matched ($re)\n";
+        if (defined($unsets{$key})) {
+            print "$self:unsetting $key\n";
+            delete($config{$key});
+            next
+        }
+        if (defined($sets{$key}) && $sets{$key} ne $$hash{$key}) {
+            if (($$hash{$key} =~ /derived/i) && ($$hash{$key} !~ /overridable/i)) {
+                die ("$self: ERROR! $key is a derived and non-overridable parameter!\n");
+            } else {
+                print "$self: Overriding $key value $$hash{$key} with $sets{$key}\n";
+                $$hash{$key} = $sets{$key};
+            }
+        }
+        my $value = $$hash{$key};
+        if (ref($value) eq "HASH") {
+            if ($key =~ /$re/) {
+                $matched = 1;
+            }
+            dump_define($matched,$prefix, $value, \@printvars, \@overridable);
+            $matched = 0;
+        } elsif (ref($value) eq "ARRAY") {
+            # print "$key : @{$value}\n";
+             $matched = 0;
+        } else {
+            if ($matched eq "1" || $key =~ /$re/) {
+                if($value =~ /derive\(.*\)/o) {
+                    $value = eval($value);
+                }
+                printf ("swerv: %-30s = $value\n",$key) if ($value !~ /derived/);
+            }
+        }
+    }
+}#}}}
+
+# Perform cmd line set/unset ############################################{{{
+sub map_set_unset {
+    if (scalar(@sets)) {
+        print "$self: Set(s) requested : @sets\n";
+        foreach (@sets) {
+            my ($key,$value) = m/(\w+)=*(\w+)*/o;
+            $value = 1 if (!defined($value));
+            $sets{$key} = $value;
+        }
+    }
+    if (scalar(@unsets)) {
+        print "$self: Unset(s) requested : @sets\n";
+        foreach (@unsets) {
+            $unsets{$_} = 1;
+        }
+    }
+} #}}}
+#}}}
+
+
+# If arg looks like a hexadecimal string, then convert it to decimal.#{{{
+# Otherwise, return arg.
+sub decimal {
+    my ($x) = @_;
+    return hex($x)  if $x =~ /^0x/o;
+    return $x;
+}#}}}
+
+# Collect memory protection specs (array of address pairs) in the given
+# resutls array. Tag is either "data" or "inst".
+sub collect_mem_protection {
+    my ($tag, $config, $results) = @_;
+    return unless exists $config{protection};
+
+    my $prot = $config{protection};
+
+    my $enable_tag = $tag . "_access_enable";
+    my $addr_tag = $tag . "_access_addr";
+    my $mask_tag = $tag . "_access_mask";
+
+    foreach my $key (keys %{$prot}) {
+        next unless $key =~ /^$enable_tag(\d+)$/;
+        my $ix = $1;
+
+        my $enable = $prot->{$key};
+        if ($enable !~ /[01]$/) {
+            warn("Invalid value for protection entry $key: $enable\n");
+            next;
+        }
+
+        next unless ($enable eq "1" or $enable eq "1'b1");
+
+        if (! exists $prot->{"$addr_tag$ix"}) {
+            warn("Missing $addr_tag$ix\n");
+            next;
+        }
+
+        if (! exists $prot->{"$mask_tag$ix"}) {
+            warn("Missing $mask_tag$ix\n");
+            next;
+        }
+
+        my $addr = $prot->{"$addr_tag$ix"};
+        my $mask = $prot->{"$mask_tag$ix"};
+
+        if ($addr !~ /^0x[0-9a-fA-F]+$/) {
+            warn("Invalid $addr_tag$ix: $addr\n");
+            next;
+        }
+
+        if ($mask !~ /^0x[0-9a-fA-F]+$/) {
+            warn("Invalid $mask_tag$ix: $mask\n");
+            next;
+        }
+
+        if ((hex($addr) & hex($mask)) != 0) {
+            warn("Protection mask bits overlap address bits in mask $mask and addr $addr\n");
+        }
+
+        if ($mask !~ /^0x0*[137]?f*$/) {
+            warn("Protection  $tag mask ($mask) must have all its one bits to the right of its zero bits\n");
+            next;
+        }
+
+        my $start = hex($addr) & ~hex($mask) & 0xffffffff;
+        my $end = (hex($addr) | hex($mask)) & 0xffffffff;
+
+        $start = sprintf("0x%08x", $start);
+        $end = sprintf("0x%08x", $end);
+
+        push(@{$results}, [ $start, $end ]);
+    }
+}
+
+# Collect memory protection specs (array of address pairs) in the given
+# resutls array. Tag is either "data" or "inst".
+sub collect_mem_protection {
+    my ($tag, $config, $results) = @_;
+    return unless exists $config{protection};
+
+    my $prot = $config{protection};
+
+    my $enable_tag = $tag . "_access_enable";
+    my $addr_tag = $tag . "_access_addr";
+    my $mask_tag = $tag . "_access_mask";
+
+    foreach my $key (keys %{$prot}) {
+        next unless $key =~ /^$enable_tag(\d+)$/;
+        my $ix = $1;
+
+        my $enable = $prot->{$key};
+        if ($enable !~ /[01]$/) {
+            warn("Invalid value for protection entry $key: $enable\n");
+            next;
+        }
+
+        next unless ($enable eq "1" or $enable eq "1'b1");
+
+        if (! exists $prot->{"$addr_tag$ix"}) {
+            warn("Missing $addr_tag$ix\n");
+            next;
+        }
+
+        if (! exists $prot->{"$mask_tag$ix"}) {
+            warn("Missing $mask_tag$ix\n");
+            next;
+        }
+
+        my $addr = $prot->{"$addr_tag$ix"};
+        my $mask = $prot->{"$mask_tag$ix"};
+
+        if ($addr !~ /^0x[0-9a-fA-F]+$/) {
+            warn("Invalid $addr_tag$ix: $addr\n");
+            next;
+        }
+
+        if ($mask !~ /^0x[0-9a-fA-F]+$/) {
+            warn("Invalid $mask_tag$ix: $mask\n");
+            next;
+        }
+
+        if ((hex($addr) & hex($mask)) != 0) {
+            warn("Protection mask bits overlap address bits in mask $mask and addr $addr\n");
+        }
+
+        if ($mask !~ /^0x0*[137]?f*$/) {
+            warn("Protection mask ($mask) must have all its one bits to the right of its zero bits\n");
+            next;
+        }
+
+        my $start = hex($addr) & ~hex($mask) & 0xffffffff;
+        my $end = (hex($addr) | hex($mask)) & 0xffffffff;
+
+        $start = sprintf("0x%08x", $start);
+        $end = sprintf("0x%08x", $end);
+
+        push(@{$results}, [ $start, $end ]);
+    }
+}
+
+# Collect the memory mapped registers associated with the pic (platform
+# interrup controller) to include in the whisper.json file.
+sub collect_mem_mapped_regs {
+    my ($pic, $results) = @_;
+    my $default_mask = 0;
+    $results->{default_mask} = $default_mask;
+    my $addr = hex($pic->{pic_region})*256*1024*1024 + hex($pic->{pic_offset});
+    $results->{address} = sprintf("0x%x", $addr);
+    $results->{size} = sprintf("0x%x", $pic->{pic_size}*1024);
+
+    my @names = qw ( mpiccfg meipl meip meie meigwctrl meigwclr meidels );
+    $results->{registers} = {};
+    foreach my $name (@names) {
+        my $tag = "pic_${name}_offset";
+        next unless exists $pic->{$tag};
+        my %item;
+        my $offset = hex($pic->{$tag});
+        $offset += 4  if ($name ne 'mpiccfg' and $name ne 'meip');
+        $item{address} = sprintf("0x%x", $addr + $offset);
+        $item{mask} = $pic->{"pic_${name}_mask"};
+        $item{count} = $pic->{"pic_${name}_count"};
+        $results->{registers}{$name} = \%item;
+    }
+}
+
+sub dump_whisper_config{#{{{
+    my ($config, $path) = @_;
+
+    open(my $fh, ">", "$path") or die ("Failed to open $path for writing: $!\n");
+
+    # Put the configuration parameters relevant to whisper into a hash
+    # in preparation for a JSON dump.
+    my %jh; # Json hash
+
+    # Collect top-level integer entries.
+    foreach my $tag (qw( harts xlen )) {
+        $jh{$tag} = $config{$tag} + 0 if exists $config{$tag};
+    }
+
+    # Collect top-level string/hex entries.
+    foreach my $tag (qw ( reset_vec nmi_vec num_mmode_perf_regs max_mmode_perf_event
+                     even_odd_trigger_chains)) {
+        $jh{$tag} = $config{$tag} if exists $config{$tag};
+    }
+
+    # Collect memory map configs.
+    my (@inst_mem_prot, @data_mem_prot);
+    collect_mem_protection("inst", $config, \@inst_mem_prot);
+    collect_mem_protection("data", $config, \@data_mem_prot);
+    $jh{memmap}{inst} = [@inst_mem_prot] if @inst_mem_prot;
+    $jh{memmap}{data} = [@data_mem_prot] if @data_mem_prot;
+    $config{memmap}{consoleio} = $config{memmap}{serialio} if exists $config{memmap}{serialio};
+    foreach my $tag (qw ( size page_size serialio consoleio)) {
+        $jh{memmap}{$tag} = $config{memmap}{$tag} if exists $config{memmap}{$tag};
+    }
+
+    # Collect load/store-error rollback parameter.
+    if (exists $config{testbench} and exists $config{testbench}{sterr_rollback}) {
+        $jh{store_error_rollback} = $config{testbench}{sterr_rollback};
+    }
+    if (exists $config{testbench} and exists $config{testbench}{lderr_rollback}) {
+        $jh{load_error_rollback} = $config{testbench}{lderr_rollback};
+    }
+
+    # Collect dccm configs
+    if (exists $config{dccm} and exists $config{dccm}{dccm_enable}) {
+        $jh{dccm}{region} = $config{dccm}{dccm_region};
+        $jh{dccm}{size} = 1024*decimal($config{dccm}{dccm_size}); # From 1k to bytes
+        $jh{dccm}{offset} = $config{dccm}{dccm_offset};
+
+        $jh{dccm}{size} = sprintf("0x%x", $jh{dccm}{size});
+    }
+
+    # Collect icccm configs.
+    if (exists $config{iccm} and exists $config{iccm}{iccm_enable}) {
+        $jh{iccm}{region} = $config{iccm}{iccm_region};
+        $jh{iccm}{size} = 1024*decimal($config{iccm}{iccm_size}); # From 1k to bytes
+        $jh{iccm}{offset} = $config{iccm}{iccm_offset};
+
+        $jh{iccm}{size} = sprintf("0x%x", $jh{iccm}{size});
+    }
+
+    # Collect CSRs
+
+    $jh{csr} = $config{csr} if exists $config{csr};
+
+    # Collect pic configs.
+    if (exists $config{pic}) {
+        my %mem_mapped;
+        collect_mem_mapped_regs($config{pic}, \%mem_mapped);
+        $jh{'memory_mapped_registers'} = \%mem_mapped;
+
+        # This is now deprecated. To be removed soon.
+        while (my ($k, $v) = each %{$config{pic}}) {
+            next if $k eq 'pic_base_addr';  # derived from region and offset
+            if ($k eq 'pic_size') {
+                $v *= 1024;  # from kbytes to bytes
+                $v = sprintf("0x%x", $v);
+            }
+            $k =~ s/^pic_//o;
+            $v += 0 if $v =~ /^\d+$/o;
+            $jh{pic}{$k} = $v;
+        }
+    }
+
+    # Collect triggers.
+    $jh{triggers} = $config{triggers} if exists $config{triggers};
+
+    # Dump JSON config file.
+    my $json = JSON->new->allow_nonref;
+    my $text = $json->pretty->encode(\%jh);
+    print($fh $text);
+
+    close $fh;
+}#}}}
+
+
+# Checker for iccm/dccm/pic sub-region address alignment. Address must be a multiple
+# of size  or next higher power of 2 if size is not a power of 2.
+sub check_addr_align {
+    my ($section, $addr, $size) = @_;
+
+    die("Invalid $section size: $size\n")  if $size <= 0;
+
+    my $log_size = log2($size);
+    my $p2 = 1 << $log_size;
+    $size = 2*$p2  if $size != $p2;
+
+    if (($addr % $size) != 0) {
+        printf("Address of $section area(0x%x) is not a multiple of its size (0x%x)\n",
+               $addr, $size);
+        exit(1);
+    }
+}
+
+
+sub log2 {
+    my ($n) = @_;
+    return log($n)/log(2);
+}
+
+sub gen_default_linker_script {#{{{
+
+    open (FILE, ">$linkerfile") || die "Cannot open $linkerfile for writing $!";
+    print "$self: Writing $linkerfile\n";
+    print FILE "/*\n";
+    print_header();
+
+    my $io = "0xd0580000";
+    $io = $config{memmap}{serialio} if exists $config{memmap}{serialio};
+
+    my $iccm = ""; my $iccm_ctl = "";
+    if (exists $config{iccm} and $config{iccm}{iccm_enable}) {
+        my $sa = $config{iccm}{iccm_sadr}; my $ea = $config{iccm}{iccm_eadr};
+        $iccm = " . = $sa ;";
+        $iccm_ctl = "  . = 0xfffffff0; .iccm.ctl . : { LONG($sa); LONG($ea) }" ;
+    }
+
+    my $sa = $config{memmap}{external_data}; my $dccm_ctl = "";
+    if (exists $config{dccm} and $config{dccm}{dccm_enable}) {
+        $sa = $config{dccm}{dccm_sadr};
+        $dccm_ctl = "  . = 0xfffffff8; .data.ctl : { LONG($sa); LONG(STACK) }" ;
+    }
+    my $data_loc = "  . = $sa ;";
+
+    print FILE  <<EOF;
+*/
+
+OUTPUT_ARCH( "riscv" )
+ENTRY(_start)
+
+SECTIONS
+{
+  . = $config{reset_vec};
+  .text.init .  : { *(.text.init) }
+  $iccm
+  .text . : { *(.text) }
+  _end = .;
+  . = $io;
+  .data.io .  : { *(.data.io) }
+  $data_loc
+  .data  :  ALIGN(0x800) { *(.*data) *(.rodata*)}
+  .bss :  {BSS_START = .; *(.*bss)}
+  BSS_END = .;
+  STACK = ALIGN(16) + 0x1000;
+  $iccm_ctl
+  $dccm_ctl
+}
+
+EOF
+    close FILE;
+} #}}}
+
diff --git a/test/helloworld/tb_top.sv b/test/helloworld/tb_top.sv
new file mode 100644
index 0000000..6500a68
--- /dev/null
+++ b/test/helloworld/tb_top.sv
@@ -0,0 +1,1115 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2020 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+`ifdef VERILATOR
+module tb_top ( input bit core_clk);
+`else
+module tb_top;
+    bit                         core_clk;
+`endif
+    logic                       rst_l;
+    logic                       porst_l;
+    logic                       nmi_int;
+
+    logic        [31:0]         reset_vector;
+    logic        [31:0]         nmi_vector;
+    logic        [31:1]         jtag_id;
+
+    logic        [31:0]         ic_haddr;
+    logic        [2:0]          ic_hburst;
+    logic                       ic_hmastlock;
+    logic        [3:0]          ic_hprot;
+    logic        [2:0]          ic_hsize;
+    logic        [1:0]          ic_htrans;
+    logic                       ic_hwrite;
+    logic        [63:0]         ic_hrdata;
+    logic                       ic_hready;
+    logic                       ic_hresp;
+
+    logic        [31:0]         lsu_haddr;
+    logic        [2:0]          lsu_hburst;
+    logic                       lsu_hmastlock;
+    logic        [3:0]          lsu_hprot;
+    logic        [2:0]          lsu_hsize;
+    logic        [1:0]          lsu_htrans;
+    logic                       lsu_hwrite;
+    logic        [63:0]         lsu_hrdata;
+    logic        [63:0]         lsu_hwdata;
+    logic                       lsu_hready;
+    logic                       lsu_hresp;
+
+    logic        [31:0]         sb_haddr;
+    logic        [2:0]          sb_hburst;
+    logic                       sb_hmastlock;
+    logic        [3:0]          sb_hprot;
+    logic        [2:0]          sb_hsize;
+    logic        [1:0]          sb_htrans;
+    logic                       sb_hwrite;
+
+    logic        [63:0]         sb_hrdata;
+    logic        [63:0]         sb_hwdata;
+    logic                       sb_hready;
+    logic                       sb_hresp;
+
+    logic        [63:0]         trace_rv_i_insn_ip;
+    logic        [63:0]         trace_rv_i_address_ip;
+    logic        [2:0]          trace_rv_i_valid_ip;
+    logic        [2:0]          trace_rv_i_exception_ip;
+    logic        [4:0]          trace_rv_i_ecause_ip;
+    logic        [2:0]          trace_rv_i_interrupt_ip;
+    logic        [31:0]         trace_rv_i_tval_ip;
+
+    logic                       o_debug_mode_status;
+    logic        [1:0]          dec_tlu_perfcnt0;
+    logic        [1:0]          dec_tlu_perfcnt1;
+    logic        [1:0]          dec_tlu_perfcnt2;
+    logic        [1:0]          dec_tlu_perfcnt3;
+
+
+    logic                       jtag_tdo;
+    logic                       o_cpu_halt_ack;
+    logic                       o_cpu_halt_status;
+    logic                       o_cpu_run_ack;
+
+    logic                       mailbox_write;
+    logic        [63:0]         dma_hrdata;
+    logic        [63:0]         dma_hwdata;
+    logic                       dma_hready;
+    logic                       dma_hresp;
+
+    logic                       mpc_debug_halt_req;
+    logic                       mpc_debug_run_req;
+    logic                       mpc_reset_run_req;
+    logic                       mpc_debug_halt_ack;
+    logic                       mpc_debug_run_ack;
+    logic                       debug_brkpt_status;
+
+    bit        [31:0]           cycleCnt;
+    logic                       mailbox_data_val;
+
+    wire                        dma_hready_out;
+    int                         commit_count;
+
+    logic                       wb_valid[1:0];
+    logic [4:0]                 wb_dest[1:0];
+    logic [31:0]                wb_data[1:0];
+
+`ifdef RV_BUILD_AXI4
+   //-------------------------- LSU AXI signals--------------------------
+   // AXI Write Channels
+    wire                        lsu_axi_awvalid;
+    wire                        lsu_axi_awready;
+    wire [`RV_LSU_BUS_TAG-1:0]  lsu_axi_awid;
+    wire [31:0]                 lsu_axi_awaddr;
+    wire [3:0]                  lsu_axi_awregion;
+    wire [7:0]                  lsu_axi_awlen;
+    wire [2:0]                  lsu_axi_awsize;
+    wire [1:0]                  lsu_axi_awburst;
+    wire                        lsu_axi_awlock;
+    wire [3:0]                  lsu_axi_awcache;
+    wire [2:0]                  lsu_axi_awprot;
+    wire [3:0]                  lsu_axi_awqos;
+
+    wire                        lsu_axi_wvalid;
+    wire                        lsu_axi_wready;
+    wire [63:0]                 lsu_axi_wdata;
+    wire [7:0]                  lsu_axi_wstrb;
+    wire                        lsu_axi_wlast;
+
+    wire                        lsu_axi_bvalid;
+    wire                        lsu_axi_bready;
+    wire [1:0]                  lsu_axi_bresp;
+    wire [`RV_LSU_BUS_TAG-1:0]  lsu_axi_bid;
+
+    // AXI Read Channels
+    wire                        lsu_axi_arvalid;
+    wire                        lsu_axi_arready;
+    wire [`RV_LSU_BUS_TAG-1:0]  lsu_axi_arid;
+    wire [31:0]                 lsu_axi_araddr;
+    wire [3:0]                  lsu_axi_arregion;
+    wire [7:0]                  lsu_axi_arlen;
+    wire [2:0]                  lsu_axi_arsize;
+    wire [1:0]                  lsu_axi_arburst;
+    wire                        lsu_axi_arlock;
+    wire [3:0]                  lsu_axi_arcache;
+    wire [2:0]                  lsu_axi_arprot;
+    wire [3:0]                  lsu_axi_arqos;
+
+    wire                        lsu_axi_rvalid;
+    wire                        lsu_axi_rready;
+    wire [`RV_LSU_BUS_TAG-1:0]  lsu_axi_rid;
+    wire [63:0]                 lsu_axi_rdata;
+    wire [1:0]                  lsu_axi_rresp;
+    wire                        lsu_axi_rlast;
+
+    //-------------------------- IFU AXI signals--------------------------
+    // AXI Write Channels
+    wire                        ifu_axi_awvalid;
+    wire                        ifu_axi_awready;
+    wire [`RV_IFU_BUS_TAG-1:0]  ifu_axi_awid;
+    wire [31:0]                 ifu_axi_awaddr;
+    wire [3:0]                  ifu_axi_awregion;
+    wire [7:0]                  ifu_axi_awlen;
+    wire [2:0]                  ifu_axi_awsize;
+    wire [1:0]                  ifu_axi_awburst;
+    wire                        ifu_axi_awlock;
+    wire [3:0]                  ifu_axi_awcache;
+    wire [2:0]                  ifu_axi_awprot;
+    wire [3:0]                  ifu_axi_awqos;
+
+    wire                        ifu_axi_wvalid;
+    wire                        ifu_axi_wready;
+    wire [63:0]                 ifu_axi_wdata;
+    wire [7:0]                  ifu_axi_wstrb;
+    wire                        ifu_axi_wlast;
+
+    wire                        ifu_axi_bvalid;
+    wire                        ifu_axi_bready;
+    wire [1:0]                  ifu_axi_bresp;
+    wire [`RV_IFU_BUS_TAG-1:0]  ifu_axi_bid;
+
+    // AXI Read Channels
+    wire                        ifu_axi_arvalid;
+    wire                        ifu_axi_arready;
+    wire [`RV_IFU_BUS_TAG-1:0]  ifu_axi_arid;
+    wire [31:0]                 ifu_axi_araddr;
+    wire [3:0]                  ifu_axi_arregion;
+    wire [7:0]                  ifu_axi_arlen;
+    wire [2:0]                  ifu_axi_arsize;
+    wire [1:0]                  ifu_axi_arburst;
+    wire                        ifu_axi_arlock;
+    wire [3:0]                  ifu_axi_arcache;
+    wire [2:0]                  ifu_axi_arprot;
+    wire [3:0]                  ifu_axi_arqos;
+
+    wire                        ifu_axi_rvalid;
+    wire                        ifu_axi_rready;
+    wire [`RV_IFU_BUS_TAG-1:0]  ifu_axi_rid;
+    wire [63:0]                 ifu_axi_rdata;
+    wire [1:0]                  ifu_axi_rresp;
+    wire                        ifu_axi_rlast;
+
+    //-------------------------- SB AXI signals--------------------------
+    // AXI Write Channels
+    wire                        sb_axi_awvalid;
+    wire                        sb_axi_awready;
+    wire [`RV_SB_BUS_TAG-1:0]   sb_axi_awid;
+    wire [31:0]                 sb_axi_awaddr;
+    wire [3:0]                  sb_axi_awregion;
+    wire [7:0]                  sb_axi_awlen;
+    wire [2:0]                  sb_axi_awsize;
+    wire [1:0]                  sb_axi_awburst;
+    wire                        sb_axi_awlock;
+    wire [3:0]                  sb_axi_awcache;
+    wire [2:0]                  sb_axi_awprot;
+    wire [3:0]                  sb_axi_awqos;
+
+    wire                        sb_axi_wvalid;
+    wire                        sb_axi_wready;
+    wire [63:0]                 sb_axi_wdata;
+    wire [7:0]                  sb_axi_wstrb;
+    wire                        sb_axi_wlast;
+
+    wire                        sb_axi_bvalid;
+    wire                        sb_axi_bready;
+    wire [1:0]                  sb_axi_bresp;
+    wire [`RV_SB_BUS_TAG-1:0]   sb_axi_bid;
+
+    // AXI Read Channels
+    wire                        sb_axi_arvalid;
+    wire                        sb_axi_arready;
+    wire [`RV_SB_BUS_TAG-1:0]   sb_axi_arid;
+    wire [31:0]                 sb_axi_araddr;
+    wire [3:0]                  sb_axi_arregion;
+    wire [7:0]                  sb_axi_arlen;
+    wire [2:0]                  sb_axi_arsize;
+    wire [1:0]                  sb_axi_arburst;
+    wire                        sb_axi_arlock;
+    wire [3:0]                  sb_axi_arcache;
+    wire [2:0]                  sb_axi_arprot;
+    wire [3:0]                  sb_axi_arqos;
+
+    wire                        sb_axi_rvalid;
+    wire                        sb_axi_rready;
+    wire [`RV_SB_BUS_TAG-1:0]   sb_axi_rid;
+    wire [63:0]                 sb_axi_rdata;
+    wire [1:0]                  sb_axi_rresp;
+    wire                        sb_axi_rlast;
+
+   //-------------------------- DMA AXI signals--------------------------
+   // AXI Write Channels
+    wire                        dma_axi_awvalid;
+    wire                        dma_axi_awready;
+    wire [`RV_DMA_BUS_TAG-1:0]  dma_axi_awid;
+    wire [31:0]                 dma_axi_awaddr;
+    wire [2:0]                  dma_axi_awsize;
+    wire [2:0]                  dma_axi_awprot;
+    wire [7:0]                  dma_axi_awlen;
+    wire [1:0]                  dma_axi_awburst;
+
+
+    wire                        dma_axi_wvalid;
+    wire                        dma_axi_wready;
+    wire [63:0]                 dma_axi_wdata;
+    wire [7:0]                  dma_axi_wstrb;
+    wire                        dma_axi_wlast;
+
+    wire                        dma_axi_bvalid;
+    wire                        dma_axi_bready;
+    wire [1:0]                  dma_axi_bresp;
+    wire [`RV_DMA_BUS_TAG-1:0]  dma_axi_bid;
+
+    // AXI Read Channels
+    wire                        dma_axi_arvalid;
+    wire                        dma_axi_arready;
+    wire [`RV_DMA_BUS_TAG-1:0]  dma_axi_arid;
+    wire [31:0]                 dma_axi_araddr;
+    wire [2:0]                  dma_axi_arsize;
+    wire [2:0]                  dma_axi_arprot;
+    wire [7:0]                  dma_axi_arlen;
+    wire [1:0]                  dma_axi_arburst;
+
+    wire                        dma_axi_rvalid;
+    wire                        dma_axi_rready;
+    wire [`RV_DMA_BUS_TAG-1:0]  dma_axi_rid;
+    wire [63:0]                 dma_axi_rdata;
+    wire [1:0]                  dma_axi_rresp;
+    wire                        dma_axi_rlast;
+
+    wire                        lmem_axi_arvalid;
+    wire                        lmem_axi_arready;
+
+    wire                        lmem_axi_rvalid;
+    wire [`RV_LSU_BUS_TAG-1:0]  lmem_axi_rid;
+    wire [1:0]                  lmem_axi_rresp;
+    wire [63:0]                 lmem_axi_rdata;
+    wire                        lmem_axi_rlast;
+    wire                        lmem_axi_rready;
+
+    wire                        lmem_axi_awvalid;
+    wire                        lmem_axi_awready;
+
+    wire                        lmem_axi_wvalid;
+    wire                        lmem_axi_wready;
+
+    wire [1:0]                  lmem_axi_bresp;
+    wire                        lmem_axi_bvalid;
+    wire [`RV_LSU_BUS_TAG-1:0]  lmem_axi_bid;
+    wire                        lmem_axi_bready;
+
+
+`endif
+    wire[63:0]                  WriteData;
+    string                      abi_reg[32]; // ABI register names
+
+`define DEC rvtop.swerv.dec
+
+    assign mailbox_write = lmem.mailbox_write;
+    assign WriteData = lmem.WriteData;
+    assign mailbox_data_val = WriteData[7:0] > 8'h5 && WriteData[7:0] < 8'h7f;
+
+    parameter MAX_CYCLES = 10_000_000;
+
+    integer fd, tp, el;
+
+    always @(negedge core_clk) begin
+        cycleCnt <= cycleCnt+1;
+        // Test timeout monitor
+        if(cycleCnt == MAX_CYCLES) begin
+            $display ("Hit max cycle count (%0d) .. stopping",cycleCnt);
+            $finish;
+        end
+        // cansol Monitor
+        if( mailbox_data_val & mailbox_write) begin
+            $fwrite(fd,"%c", WriteData[7:0]);
+            $write("%c", WriteData[7:0]);
+        end
+        // End Of test monitor
+        if(mailbox_write && WriteData[7:0] == 8'hff) begin
+            $display("\nFinished : minstret = %0d, mcycle = %0d", `DEC.tlu.minstretl[31:0],`DEC.tlu.mcyclel[31:0]);
+            $display("See \"exec.log\" for execution trace with register updates..\n");
+            $display("TEST_PASSED");
+            $finish;
+        end
+        else if(mailbox_write && WriteData[7:0] == 8'h1) begin
+            $display("TEST_FAILED");
+            $finish;
+        end
+    end
+
+
+    // trace monitor
+    always @(posedge core_clk) begin
+        wb_valid[1:0]  <= '{`DEC.dec_i1_wen_wb, `DEC.dec_i0_wen_wb};
+        wb_dest[1:0]   <= '{`DEC.dec_i1_waddr_wb, `DEC.dec_i0_waddr_wb};
+        wb_data[1:0]   <= '{`DEC.dec_i1_wdata_wb, `DEC.dec_i0_wdata_wb};
+        if (trace_rv_i_valid_ip !== 0) begin
+           $fwrite(tp,"%b,%h,%h,%0h,%0h,3,%b,%h,%h,%b\n", trace_rv_i_valid_ip, trace_rv_i_address_ip[63:32], trace_rv_i_address_ip[31:0],
+                  trace_rv_i_insn_ip[63:32], trace_rv_i_insn_ip[31:0],trace_rv_i_exception_ip,trace_rv_i_ecause_ip,
+                  trace_rv_i_tval_ip,trace_rv_i_interrupt_ip);
+           // Basic trace - no exception register updates
+           // #1 0 ee000000 b0201073 c 0b02       00000000
+           for (int i=0; i<2; i++)
+               if (trace_rv_i_valid_ip[i]==1) begin
+                   commit_count++;
+                   $fwrite (el, "%10d : %8s %0d %h %h%13s ; %s\n",cycleCnt, $sformatf("#%0d",commit_count), 0,
+                           trace_rv_i_address_ip[31+i*32 -:32], trace_rv_i_insn_ip[31+i*32-:32],
+                           (wb_dest[i] !=0 && wb_valid[i]) ?  $sformatf("%s=%h", abi_reg[wb_dest[i]], wb_data[i]) : "             ",
+                           dasm(trace_rv_i_insn_ip[31+i*32 -:32], trace_rv_i_address_ip[31+i*32-:32], wb_dest[i] & {5{wb_valid[i]}}, wb_data[i])
+                           );
+               end
+        end
+        if(`DEC.dec_nonblock_load_wen) begin
+            $fwrite (el, "%10d : %10d%22s=%h ; nbL\n", cycleCnt, 0, abi_reg[`DEC.dec_nonblock_load_waddr], `DEC.lsu_nonblock_load_data);
+            tb_top.gpr[0][`DEC.dec_nonblock_load_waddr] = `DEC.lsu_nonblock_load_data;
+        end
+    end
+
+
+    initial begin
+        abi_reg[0] = "zero";
+        abi_reg[1] = "ra";
+        abi_reg[2] = "sp";
+        abi_reg[3] = "gp";
+        abi_reg[4] = "tp";
+        abi_reg[5] = "t0";
+        abi_reg[6] = "t1";
+        abi_reg[7] = "t2";
+        abi_reg[8] = "s0";
+        abi_reg[9] = "s1";
+        abi_reg[10] = "a0";
+        abi_reg[11] = "a1";
+        abi_reg[12] = "a2";
+        abi_reg[13] = "a3";
+        abi_reg[14] = "a4";
+        abi_reg[15] = "a5";
+        abi_reg[16] = "a6";
+        abi_reg[17] = "a7";
+        abi_reg[18] = "s2";
+        abi_reg[19] = "s3";
+        abi_reg[20] = "s4";
+        abi_reg[21] = "s5";
+        abi_reg[22] = "s6";
+        abi_reg[23] = "s7";
+        abi_reg[24] = "s8";
+        abi_reg[25] = "s9";
+        abi_reg[26] = "s10";
+        abi_reg[27] = "s11";
+        abi_reg[28] = "t3";
+        abi_reg[29] = "t4";
+        abi_reg[30] = "t5";
+        abi_reg[31] = "t6";
+    // tie offs
+        jtag_id[31:28] = 4'b1;
+        jtag_id[27:12] = '0;
+        jtag_id[11:1]  = 11'h45;
+        reset_vector = 32'h0;
+        nmi_vector   = 32'hee000000;
+        nmi_int   = 0;
+
+        $readmemh("program.hex",  lmem.mem);
+        $readmemh("program.hex",  imem.mem);
+        tp = $fopen("trace_port.csv","w");
+        el = $fopen("exec.log","w");
+        $fwrite (el, "//   Cycle : #inst  hart   pc    opcode    reg=value   ; mnemonic\n");
+        $fwrite (el, "//---------------------------------------------------------------\n");
+        fd = $fopen("console.log","w");
+        commit_count = 0;
+        preload_dccm();
+        preload_iccm();
+
+`ifndef VERILATOR
+        if($test$plusargs("dumpon")) $dumpvars;
+        forever  core_clk = #5 ~core_clk;
+`endif
+    end
+
+
+    assign rst_l = cycleCnt > 5;
+    assign porst_l = cycleCnt >2;
+
+   //=========================================================================-
+   // RTL instance
+   //=========================================================================-
+swerv_wrapper rvtop (
+    .rst_l                  ( rst_l         ),
+    .dbg_rst_l              ( porst_l       ),
+    .clk                    ( core_clk      ),
+    .rst_vec                ( reset_vector[31:1]),
+    .nmi_int                ( nmi_int       ),
+    .nmi_vec                ( nmi_vector[31:1]),
+    .jtag_id                ( jtag_id[31:1]),
+
+`ifdef RV_BUILD_AHB_LITE
+    .haddr                  ( ic_haddr      ),
+    .hburst                 ( ic_hburst     ),
+    .hmastlock              ( ic_hmastlock  ),
+    .hprot                  ( ic_hprot      ),
+    .hsize                  ( ic_hsize      ),
+    .htrans                 ( ic_htrans     ),
+    .hwrite                 ( ic_hwrite     ),
+
+    .hrdata                 ( ic_hrdata[63:0]),
+    .hready                 ( ic_hready     ),
+    .hresp                  ( ic_hresp      ),
+
+    //---------------------------------------------------------------
+    // Debug AHB Master
+    //---------------------------------------------------------------
+    .sb_haddr               ( sb_haddr      ),
+    .sb_hburst              ( sb_hburst     ),
+    .sb_hmastlock           ( sb_hmastlock  ),
+    .sb_hprot               ( sb_hprot      ),
+    .sb_hsize               ( sb_hsize      ),
+    .sb_htrans              ( sb_htrans     ),
+    .sb_hwrite              ( sb_hwrite     ),
+    .sb_hwdata              ( sb_hwdata     ),
+
+    .sb_hrdata              ( sb_hrdata     ),
+    .sb_hready              ( sb_hready     ),
+    .sb_hresp               ( sb_hresp      ),
+
+    //---------------------------------------------------------------
+    // LSU AHB Master
+    //---------------------------------------------------------------
+    .lsu_haddr              ( lsu_haddr       ),
+    .lsu_hburst             ( lsu_hburst      ),
+    .lsu_hmastlock          ( lsu_hmastlock   ),
+    .lsu_hprot              ( lsu_hprot       ),
+    .lsu_hsize              ( lsu_hsize       ),
+    .lsu_htrans             ( lsu_htrans      ),
+    .lsu_hwrite             ( lsu_hwrite      ),
+    .lsu_hwdata             ( lsu_hwdata      ),
+
+    .lsu_hrdata             ( lsu_hrdata[63:0]),
+    .lsu_hready             ( lsu_hready      ),
+    .lsu_hresp              ( lsu_hresp       ),
+
+    //---------------------------------------------------------------
+    // DMA Slave
+    //---------------------------------------------------------------
+    .dma_haddr              ( '0 ),
+    .dma_hburst             ( '0 ),
+    .dma_hmastlock          ( '0 ),
+    .dma_hprot              ( '0 ),
+    .dma_hsize              ( '0 ),
+    .dma_htrans             ( '0 ),
+    .dma_hwrite             ( '0 ),
+    .dma_hwdata             ( '0 ),
+
+    .dma_hrdata             ( dma_hrdata    ),
+    .dma_hresp              ( dma_hresp     ),
+    .dma_hsel               ( 1'b1            ),
+    .dma_hreadyin           ( dma_hready_out  ),
+    .dma_hreadyout          ( dma_hready_out  ),
+`endif
+`ifdef RV_BUILD_AXI4
+    //-------------------------- LSU AXI signals--------------------------
+    // AXI Write Channels
+    .lsu_axi_awvalid        (lsu_axi_awvalid),
+    .lsu_axi_awready        (lsu_axi_awready),
+    .lsu_axi_awid           (lsu_axi_awid),
+    .lsu_axi_awaddr         (lsu_axi_awaddr),
+    .lsu_axi_awregion       (lsu_axi_awregion),
+    .lsu_axi_awlen          (lsu_axi_awlen),
+    .lsu_axi_awsize         (lsu_axi_awsize),
+    .lsu_axi_awburst        (lsu_axi_awburst),
+    .lsu_axi_awlock         (lsu_axi_awlock),
+    .lsu_axi_awcache        (lsu_axi_awcache),
+    .lsu_axi_awprot         (lsu_axi_awprot),
+    .lsu_axi_awqos          (lsu_axi_awqos),
+
+    .lsu_axi_wvalid         (lsu_axi_wvalid),
+    .lsu_axi_wready         (lsu_axi_wready),
+    .lsu_axi_wdata          (lsu_axi_wdata),
+    .lsu_axi_wstrb          (lsu_axi_wstrb),
+    .lsu_axi_wlast          (lsu_axi_wlast),
+
+    .lsu_axi_bvalid         (lsu_axi_bvalid),
+    .lsu_axi_bready         (lsu_axi_bready),
+    .lsu_axi_bresp          (lsu_axi_bresp),
+    .lsu_axi_bid            (lsu_axi_bid),
+
+
+    .lsu_axi_arvalid        (lsu_axi_arvalid),
+    .lsu_axi_arready        (lsu_axi_arready),
+    .lsu_axi_arid           (lsu_axi_arid),
+    .lsu_axi_araddr         (lsu_axi_araddr),
+    .lsu_axi_arregion       (lsu_axi_arregion),
+    .lsu_axi_arlen          (lsu_axi_arlen),
+    .lsu_axi_arsize         (lsu_axi_arsize),
+    .lsu_axi_arburst        (lsu_axi_arburst),
+    .lsu_axi_arlock         (lsu_axi_arlock),
+    .lsu_axi_arcache        (lsu_axi_arcache),
+    .lsu_axi_arprot         (lsu_axi_arprot),
+    .lsu_axi_arqos          (lsu_axi_arqos),
+
+    .lsu_axi_rvalid         (lsu_axi_rvalid),
+    .lsu_axi_rready         (lsu_axi_rready),
+    .lsu_axi_rid            (lsu_axi_rid),
+    .lsu_axi_rdata          (lsu_axi_rdata),
+    .lsu_axi_rresp          (lsu_axi_rresp),
+    .lsu_axi_rlast          (lsu_axi_rlast),
+
+    //-------------------------- IFU AXI signals--------------------------
+    // AXI Write Channels
+    .ifu_axi_awvalid        (ifu_axi_awvalid),
+    .ifu_axi_awready        (ifu_axi_awready),
+    .ifu_axi_awid           (ifu_axi_awid),
+    .ifu_axi_awaddr         (ifu_axi_awaddr),
+    .ifu_axi_awregion       (ifu_axi_awregion),
+    .ifu_axi_awlen          (ifu_axi_awlen),
+    .ifu_axi_awsize         (ifu_axi_awsize),
+    .ifu_axi_awburst        (ifu_axi_awburst),
+    .ifu_axi_awlock         (ifu_axi_awlock),
+    .ifu_axi_awcache        (ifu_axi_awcache),
+    .ifu_axi_awprot         (ifu_axi_awprot),
+    .ifu_axi_awqos          (ifu_axi_awqos),
+
+    .ifu_axi_wvalid         (ifu_axi_wvalid),
+    .ifu_axi_wready         (ifu_axi_wready),
+    .ifu_axi_wdata          (ifu_axi_wdata),
+    .ifu_axi_wstrb          (ifu_axi_wstrb),
+    .ifu_axi_wlast          (ifu_axi_wlast),
+
+    .ifu_axi_bvalid         (ifu_axi_bvalid),
+    .ifu_axi_bready         (ifu_axi_bready),
+    .ifu_axi_bresp          (ifu_axi_bresp),
+    .ifu_axi_bid            (ifu_axi_bid),
+
+    .ifu_axi_arvalid        (ifu_axi_arvalid),
+    .ifu_axi_arready        (ifu_axi_arready),
+    .ifu_axi_arid           (ifu_axi_arid),
+    .ifu_axi_araddr         (ifu_axi_araddr),
+    .ifu_axi_arregion       (ifu_axi_arregion),
+    .ifu_axi_arlen          (ifu_axi_arlen),
+    .ifu_axi_arsize         (ifu_axi_arsize),
+    .ifu_axi_arburst        (ifu_axi_arburst),
+    .ifu_axi_arlock         (ifu_axi_arlock),
+    .ifu_axi_arcache        (ifu_axi_arcache),
+    .ifu_axi_arprot         (ifu_axi_arprot),
+    .ifu_axi_arqos          (ifu_axi_arqos),
+
+    .ifu_axi_rvalid         (ifu_axi_rvalid),
+    .ifu_axi_rready         (ifu_axi_rready),
+    .ifu_axi_rid            (ifu_axi_rid),
+    .ifu_axi_rdata          (ifu_axi_rdata),
+    .ifu_axi_rresp          (ifu_axi_rresp),
+    .ifu_axi_rlast          (ifu_axi_rlast),
+
+    //-------------------------- SB AXI signals--------------------------
+    // AXI Write Channels
+    .sb_axi_awvalid         (sb_axi_awvalid),
+    .sb_axi_awready         (sb_axi_awready),
+    .sb_axi_awid            (sb_axi_awid),
+    .sb_axi_awaddr          (sb_axi_awaddr),
+    .sb_axi_awregion        (sb_axi_awregion),
+    .sb_axi_awlen           (sb_axi_awlen),
+    .sb_axi_awsize          (sb_axi_awsize),
+    .sb_axi_awburst         (sb_axi_awburst),
+    .sb_axi_awlock          (sb_axi_awlock),
+    .sb_axi_awcache         (sb_axi_awcache),
+    .sb_axi_awprot          (sb_axi_awprot),
+    .sb_axi_awqos           (sb_axi_awqos),
+
+    .sb_axi_wvalid          (sb_axi_wvalid),
+    .sb_axi_wready          (sb_axi_wready),
+    .sb_axi_wdata           (sb_axi_wdata),
+    .sb_axi_wstrb           (sb_axi_wstrb),
+    .sb_axi_wlast           (sb_axi_wlast),
+
+    .sb_axi_bvalid          (sb_axi_bvalid),
+    .sb_axi_bready          (sb_axi_bready),
+    .sb_axi_bresp           (sb_axi_bresp),
+    .sb_axi_bid             (sb_axi_bid),
+
+
+    .sb_axi_arvalid         (sb_axi_arvalid),
+    .sb_axi_arready         (sb_axi_arready),
+    .sb_axi_arid            (sb_axi_arid),
+    .sb_axi_araddr          (sb_axi_araddr),
+    .sb_axi_arregion        (sb_axi_arregion),
+    .sb_axi_arlen           (sb_axi_arlen),
+    .sb_axi_arsize          (sb_axi_arsize),
+    .sb_axi_arburst         (sb_axi_arburst),
+    .sb_axi_arlock          (sb_axi_arlock),
+    .sb_axi_arcache         (sb_axi_arcache),
+    .sb_axi_arprot          (sb_axi_arprot),
+    .sb_axi_arqos           (sb_axi_arqos),
+
+    .sb_axi_rvalid          (sb_axi_rvalid),
+    .sb_axi_rready          (sb_axi_rready),
+    .sb_axi_rid             (sb_axi_rid),
+    .sb_axi_rdata           (sb_axi_rdata),
+    .sb_axi_rresp           (sb_axi_rresp),
+    .sb_axi_rlast           (sb_axi_rlast),
+
+    //-------------------------- DMA AXI signals--------------------------
+    // AXI Write Channels
+    .dma_axi_awvalid        (dma_axi_awvalid),
+    .dma_axi_awready        (dma_axi_awready),
+    .dma_axi_awid           ('0),               // ids are not used on DMA since it always responses in order
+    .dma_axi_awaddr         (lsu_axi_awaddr),
+    .dma_axi_awsize         (lsu_axi_awsize),
+    .dma_axi_awprot         ('0),
+    .dma_axi_awlen          ('0),
+    .dma_axi_awburst        ('0),
+
+
+    .dma_axi_wvalid         (dma_axi_wvalid),
+    .dma_axi_wready         (dma_axi_wready),
+    .dma_axi_wdata          (lsu_axi_wdata),
+    .dma_axi_wstrb          (lsu_axi_wstrb),
+    .dma_axi_wlast          (1'b1),
+
+    .dma_axi_bvalid         (dma_axi_bvalid),
+    .dma_axi_bready         (dma_axi_bready),
+    .dma_axi_bresp          (dma_axi_bresp),
+    .dma_axi_bid            (),
+
+
+    .dma_axi_arvalid        (dma_axi_arvalid),
+    .dma_axi_arready        (dma_axi_arready),
+    .dma_axi_arid           ('0),
+    .dma_axi_araddr         (lsu_axi_araddr),
+    .dma_axi_arsize         (lsu_axi_arsize),
+    .dma_axi_arprot         ('0),
+    .dma_axi_arlen          ('0),
+    .dma_axi_arburst        ('0),
+
+    .dma_axi_rvalid         (dma_axi_rvalid),
+    .dma_axi_rready         (dma_axi_rready),
+    .dma_axi_rid            (),
+    .dma_axi_rdata          (dma_axi_rdata),
+    .dma_axi_rresp          (dma_axi_rresp),
+    .dma_axi_rlast          (dma_axi_rlast),
+`endif
+    .timer_int              ( 1'b0     ),
+    .extintsrc_req          ( '0  ),
+
+    .lsu_bus_clk_en         ( 1'b1  ),
+    .ifu_bus_clk_en         ( 1'b1  ),
+    .dbg_bus_clk_en         ( 1'b1  ),
+    .dma_bus_clk_en         ( 1'b1  ),
+
+    .trace_rv_i_insn_ip     (trace_rv_i_insn_ip),
+    .trace_rv_i_address_ip  (trace_rv_i_address_ip),
+    .trace_rv_i_valid_ip    (trace_rv_i_valid_ip),
+    .trace_rv_i_exception_ip(trace_rv_i_exception_ip),
+    .trace_rv_i_ecause_ip   (trace_rv_i_ecause_ip),
+    .trace_rv_i_interrupt_ip(trace_rv_i_interrupt_ip),
+    .trace_rv_i_tval_ip     (trace_rv_i_tval_ip),
+
+    .jtag_tck               ( 1'b0  ),
+    .jtag_tms               ( 1'b0  ),
+    .jtag_tdi               ( 1'b0  ),
+    .jtag_trst_n            ( 1'b0  ),
+    .jtag_tdo               ( jtag_tdo ),
+
+    .mpc_debug_halt_ack     ( mpc_debug_halt_ack),
+    .mpc_debug_halt_req     ( 1'b0),
+    .mpc_debug_run_ack      ( mpc_debug_run_ack),
+    .mpc_debug_run_req      ( 1'b1),
+    .mpc_reset_run_req      ( 1'b1),
+     .debug_brkpt_status    (debug_brkpt_status),
+
+    .i_cpu_halt_req         ( 1'b0  ),
+    .o_cpu_halt_ack         ( o_cpu_halt_ack ),
+    .o_cpu_halt_status      ( o_cpu_halt_status ),
+    .i_cpu_run_req          ( 1'b0  ),
+    .o_debug_mode_status    (o_debug_mode_status),
+    .o_cpu_run_ack          ( o_cpu_run_ack ),
+
+    .dec_tlu_perfcnt0       (dec_tlu_perfcnt0),
+    .dec_tlu_perfcnt1       (dec_tlu_perfcnt1),
+    .dec_tlu_perfcnt2       (dec_tlu_perfcnt2),
+    .dec_tlu_perfcnt3       (dec_tlu_perfcnt3),
+
+    .scan_mode              ( 1'b0 ),
+    .mbist_mode             ( 1'b0 )
+
+);
+
+
+   //=========================================================================-
+   // AHB I$ instance
+   //=========================================================================-
+`ifdef RV_BUILD_AHB_LITE
+
+ahb_sif imem (
+     // Inputs
+     .HWDATA(64'h0),
+     .HCLK(core_clk),
+     .HSEL(1'b1),
+     .HPROT(ic_hprot),
+     .HWRITE(ic_hwrite),
+     .HTRANS(ic_htrans),
+     .HSIZE(ic_hsize),
+     .HREADY(ic_hready),
+     .HRESETn(rst_l),
+     .HADDR(ic_haddr),
+     .HBURST(ic_hburst),
+
+     // Outputs
+     .HREADYOUT(ic_hready),
+     .HRESP(ic_hresp),
+     .HRDATA(ic_hrdata[63:0])
+);
+
+
+ahb_sif lmem (
+     // Inputs
+     .HWDATA(lsu_hwdata),
+     .HCLK(core_clk),
+     .HSEL(1'b1),
+     .HPROT(lsu_hprot),
+     .HWRITE(lsu_hwrite),
+     .HTRANS(lsu_htrans),
+     .HSIZE(lsu_hsize),
+     .HREADY(lsu_hready),
+     .HRESETn(rst_l),
+     .HADDR(lsu_haddr),
+     .HBURST(lsu_hburst),
+
+     // Outputs
+     .HREADYOUT(lsu_hready),
+     .HRESP(lsu_hresp),
+     .HRDATA(lsu_hrdata[63:0])
+);
+
+`endif
+`ifdef RV_BUILD_AXI4
+axi_slv #(.TAGW(`RV_IFU_BUS_TAG)) imem(
+    .aclk(core_clk),
+    .rst_l(rst_l),
+    .arvalid(ifu_axi_arvalid),
+    .arready(ifu_axi_arready),
+    .araddr(ifu_axi_araddr),
+    .arid(ifu_axi_arid),
+    .arlen(ifu_axi_arlen),
+    .arburst(ifu_axi_arburst),
+    .arsize(ifu_axi_arsize),
+
+    .rvalid(ifu_axi_rvalid),
+    .rready(ifu_axi_rready),
+    .rdata(ifu_axi_rdata),
+    .rresp(ifu_axi_rresp),
+    .rid(ifu_axi_rid),
+    .rlast(ifu_axi_rlast),
+
+    .awvalid(1'b0),
+    .awready(),
+    .awaddr('0),
+    .awid('0),
+    .awlen('0),
+    .awburst('0),
+    .awsize('0),
+
+    .wdata('0),
+    .wstrb('0),
+    .wvalid(1'b0),
+    .wready(),
+
+    .bvalid(),
+    .bready(1'b0),
+    .bresp(),
+    .bid()
+);
+
+defparam lmem.TAGW =`RV_LSU_BUS_TAG;
+
+//axi_slv #(.TAGW(`RV_LSU_BUS_TAG)) lmem(
+axi_slv  lmem(
+    .aclk(core_clk),
+    .rst_l(rst_l),
+    .arvalid(lmem_axi_arvalid),
+    .arready(lmem_axi_arready),
+    .araddr(lsu_axi_araddr),
+    .arid(lsu_axi_arid),
+    .arlen(lsu_axi_arlen),
+    .arburst(lsu_axi_arburst),
+    .arsize(lsu_axi_arsize),
+
+    .rvalid(lmem_axi_rvalid),
+    .rready(lmem_axi_rready),
+    .rdata(lmem_axi_rdata),
+    .rresp(lmem_axi_rresp),
+    .rid(lmem_axi_rid),
+    .rlast(lmem_axi_rlast),
+
+    .awvalid(lmem_axi_awvalid),
+    .awready(lmem_axi_awready),
+    .awaddr(lsu_axi_awaddr),
+    .awid(lsu_axi_awid),
+    .awlen(lsu_axi_awlen),
+    .awburst(lsu_axi_awburst),
+    .awsize(lsu_axi_awsize),
+
+    .wdata(lsu_axi_wdata),
+    .wstrb(lsu_axi_wstrb),
+    .wvalid(lmem_axi_wvalid),
+    .wready(lmem_axi_wready),
+
+    .bvalid(lmem_axi_bvalid),
+    .bready(lmem_axi_bready),
+    .bresp(lmem_axi_bresp),
+    .bid(lmem_axi_bid)
+);
+
+axi_lsu_dma_bridge # (`RV_LSU_BUS_TAG,`RV_LSU_BUS_TAG ) bridge(
+    .clk(core_clk),
+    .reset_l(rst_l),
+
+    .m_arvalid(lsu_axi_arvalid),
+    .m_arid(lsu_axi_arid),
+    .m_araddr(lsu_axi_araddr),
+    .m_arready(lsu_axi_arready),
+
+    .m_rvalid(lsu_axi_rvalid),
+    .m_rready(lsu_axi_rready),
+    .m_rdata(lsu_axi_rdata),
+    .m_rid(lsu_axi_rid),
+    .m_rresp(lsu_axi_rresp),
+    .m_rlast(lsu_axi_rlast),
+
+    .m_awvalid(lsu_axi_awvalid),
+    .m_awid(lsu_axi_awid),
+    .m_awaddr(lsu_axi_awaddr),
+    .m_awready(lsu_axi_awready),
+
+    .m_wvalid(lsu_axi_wvalid),
+    .m_wready(lsu_axi_wready),
+
+    .m_bresp(lsu_axi_bresp),
+    .m_bvalid(lsu_axi_bvalid),
+    .m_bid(lsu_axi_bid),
+    .m_bready(lsu_axi_bready),
+
+    .s0_arvalid(lmem_axi_arvalid),
+    .s0_arready(lmem_axi_arready),
+
+    .s0_rvalid(lmem_axi_rvalid),
+    .s0_rid(lmem_axi_rid),
+    .s0_rresp(lmem_axi_rresp),
+    .s0_rdata(lmem_axi_rdata),
+    .s0_rlast(lmem_axi_rlast),
+    .s0_rready(lmem_axi_rready),
+
+    .s0_awvalid(lmem_axi_awvalid),
+    .s0_awready(lmem_axi_awready),
+
+    .s0_wvalid(lmem_axi_wvalid),
+    .s0_wready(lmem_axi_wready),
+    .s0_bresp(lmem_axi_bresp),
+    .s0_bvalid(lmem_axi_bvalid),
+    .s0_bid(lmem_axi_bid),
+    .s0_bready(lmem_axi_bready),
+
+
+    .s1_arvalid(dma_axi_arvalid),
+    .s1_arready(dma_axi_arready),
+
+    .s1_rvalid(dma_axi_rvalid),
+    .s1_rresp(dma_axi_rresp),
+    .s1_rdata(dma_axi_rdata),
+    .s1_rlast(dma_axi_rlast),
+    .s1_rready(dma_axi_rready),
+
+    .s1_awvalid(dma_axi_awvalid),
+    .s1_awready(dma_axi_awready),
+
+    .s1_wvalid(dma_axi_wvalid),
+    .s1_wready(dma_axi_wready),
+
+    .s1_bresp(dma_axi_bresp),
+    .s1_bvalid(dma_axi_bvalid),
+    .s1_bready(dma_axi_bready)
+
+);
+
+`endif
+
+task preload_iccm;
+bit[31:0] data;
+bit[31:0] addr, eaddr, saddr;
+
+/*
+addresses:
+ 0xfffffff0 - ICCM start address to load
+ 0xfffffff4 - ICCM end address to load
+*/
+
+addr = 'hffff_fff0;
+saddr = {lmem.mem[addr+3],lmem.mem[addr+2],lmem.mem[addr+1],lmem.mem[addr]};
+if ( (saddr < `RV_ICCM_SADR) || (saddr > `RV_ICCM_EADR)) return;
+`ifndef RV_ICCM_ENABLE
+    $display("********************************************************");
+    $display("ICCM preload: there is no ICCM in SweRV, terminating !!!");
+    $display("********************************************************");
+    $finish;
+`endif
+addr += 4;
+eaddr = {lmem.mem[addr+3],lmem.mem[addr+2],lmem.mem[addr+1],lmem.mem[addr]};
+$display("ICCM pre-load from %h to %h", saddr, eaddr);
+
+for(addr= saddr; addr <= eaddr; addr+=4) begin
+    data = {imem.mem[addr+3],imem.mem[addr+2],imem.mem[addr+1],imem.mem[addr]};
+    slam_iccm_ram(addr, data == 0 ? 0 : {riscv_ecc32(data),data});
+end
+
+endtask
+
+
+task preload_dccm;
+bit[31:0] data;
+bit[31:0] addr, saddr, eaddr;
+
+/*
+addresses:
+ 0xffff_fff8 - DCCM start address to load
+ 0xffff_fffc - DCCM end address to load
+*/
+
+addr = 'hffff_fff8;
+saddr = {lmem.mem[addr+3],lmem.mem[addr+2],lmem.mem[addr+1],lmem.mem[addr]};
+if (saddr < `RV_DCCM_SADR || saddr > `RV_DCCM_EADR) return;
+`ifndef RV_DCCM_ENABLE
+    $display("********************************************************");
+    $display("DCCM preload: there is no DCCM in SweRV, terminating !!!");
+    $display("********************************************************");
+    $finish;
+`endif
+addr += 4;
+eaddr = {lmem.mem[addr+3],lmem.mem[addr+2],lmem.mem[addr+1],lmem.mem[addr]};
+$display("DCCM pre-load from %h to %h", saddr, eaddr);
+
+for(addr=saddr; addr <= eaddr; addr+=4) begin
+    data = {lmem.mem[addr+3],lmem.mem[addr+2],lmem.mem[addr+1],lmem.mem[addr]};
+    slam_dccm_ram(addr, data == 0 ? 0 : {riscv_ecc32(data),data});
+end
+
+endtask
+
+`define DRAM(bank) \
+    rvtop.mem.Gen_dccm_enable.dccm.mem_bank[bank].dccm_bank.ram_core
+
+`define ICCM_PATH `RV_TOP.mem.iccm
+`define IRAM0(bk) `ICCM_PATH.mem_bank[bk].iccm_bank_lo0.ram_core
+`define IRAM1(bk) `ICCM_PATH.mem_bank[bk].iccm_bank_lo1.ram_core
+`define IRAM2(bk) `ICCM_PATH.mem_bank[bk].iccm_bank_hi0.ram_core
+`define IRAM3(bk) `ICCM_PATH.mem_bank[bk].iccm_bank_hi1.ram_core
+
+
+task slam_iccm_ram(input [31:0] addr, input[38:0] data);
+int bank, indx;
+`ifdef RV_ICCM_ENABLE
+bank = get_iccm_bank(addr, indx);
+case(bank)
+0: `IRAM0(0)[indx] = data;
+1: `IRAM1(0)[indx] = data;
+2: `IRAM2(0)[indx] = data;
+3: `IRAM3(0)[indx] = data;
+`ifdef RV_ICCM_NUM_BANKS_8
+4: `IRAM0(1)[indx] = data;
+5: `IRAM1(1)[indx] = data;
+6: `IRAM2(1)[indx] = data;
+7: `IRAM3(1)[indx] = data;
+`endif
+`ifdef RV_ICCM_NUM_BANKS_16
+8: `IRAM0(2)[indx] = data;
+9: `IRAM1(2)[indx] = data;
+10: `IRAM2(2)[indx] = data;
+11: `IRAM3(2)[indx] = data;
+12: `IRAM0(3)[indx] = data;
+13: `IRAM1(3)[indx] = data;
+14: `IRAM2(3)[indx] = data;
+15: `IRAM3(3)[indx] = data;
+`endif
+endcase
+`endif
+endtask
+
+task slam_dccm_ram(input [31:0] addr, input[38:0] data);
+int bank, indx;
+`ifdef RV_DCCM_ENABLE
+bank = get_dccm_bank(addr, indx);
+case(bank)
+0: `DRAM(0)[indx] = data;
+1: `DRAM(1)[indx] = data;
+`ifdef RV_DCCM_NUM_BANKS_4
+2: `DRAM(2)[indx] = data;
+3: `DRAM(3)[indx] = data;
+`endif
+`ifdef RV_DCCM_NUM_BANKS_8
+2: `DRAM(2)[indx] = data;
+3: `DRAM(3)[indx] = data;
+4: `DRAM(4)[indx] = data;
+5: `DRAM(5)[indx] = data;
+6: `DRAM(6)[indx] = data;
+7: `DRAM(7)[indx] = data;
+`endif
+endcase
+`endif
+endtask
+
+function[6:0] riscv_ecc32(input[31:0] data);
+reg[6:0] synd;
+synd[0] = ^(data & 32'h56aa_ad5b);
+synd[1] = ^(data & 32'h9b33_366d);
+synd[2] = ^(data & 32'he3c3_c78e);
+synd[3] = ^(data & 32'h03fc_07f0);
+synd[4] = ^(data & 32'h03ff_f800);
+synd[5] = ^(data & 32'hfc00_0000);
+synd[6] = ^{data, synd[5:0]};
+return synd;
+endfunction
+
+function int get_dccm_bank(input int addr,  output int bank_idx);
+`ifdef RV_DCCM_NUM_BANKS_2
+    bank_idx = int'(addr[`RV_DCCM_BITS-1:3]);
+    return int'( addr[2]);
+`elsif RV_DCCM_NUM_BANKS_4
+    bank_idx = int'(addr[`RV_DCCM_BITS-1:4]);
+    return int'(addr[3:2]);
+`elsif RV_DCCM_NUM_BANKS_8
+    bank_idx = int'(addr[`RV_DCCM_BITS-1:5]);
+    return int'( addr[4:2]);
+`endif
+endfunction
+
+function int get_iccm_bank(input int addr,  output int bank_idx);
+`ifdef RV_ICCM_NUM_BANKS_4
+    bank_idx = int'(addr[`RV_ICCM_BITS-1:4]);
+    return int'( addr[3:2]);
+`elsif RV_ICCM_NUM_BANKS_8
+    bank_idx = int'(addr[`RV_ICCM_BITS-1:5]);
+    return int'(addr[4:2]);
+`else
+    bank_idx = int'(addr[`RV_ICCM_BITS-1:6]);
+    return int'( addr[5:2]);
+`endif
+endfunction
+
+/* verilator lint_off WIDTH */
+/* verilator lint_off CASEINCOMPLETE */
+`include "dasm.svi"
+/* verilator lint_on CASEINCOMPLETE */
+/* verilator lint_on WIDTH */
+
+
+endmodule
+`ifdef RV_BUILD_AXI4
+`include "axi_lsu_dma_bridge.sv"
+`endif
diff --git a/test/helloworld/test_tb_top.cpp b/test/helloworld/test_tb_top.cpp
new file mode 100644
index 0000000..899caf1
--- /dev/null
+++ b/test/helloworld/test_tb_top.cpp
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright 2019 Western Digital Corporation or its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+#include <stdlib.h>
+#include <iostream>
+#include <utility>
+#include <string>
+#include "Vtb_top.h"
+#include "verilated.h"
+#include "verilated_vcd_c.h"
+
+
+vluint64_t main_time = 0;
+
+double sc_time_stamp () {
+ return main_time;
+}
+
+
+int main(int argc, char** argv) {
+  std::cout << "\nVerilatorTB: Start of sim\n" << std::endl;
+
+  Verilated::commandArgs(argc, argv);
+
+  Vtb_top* tb = new Vtb_top;
+
+  // init trace dump
+  VerilatedVcdC* tfp = NULL;
+
+#if VM_TRACE
+  Verilated::traceEverOn(true);
+  tfp = new VerilatedVcdC;
+  tb->trace (tfp, 24);
+  tfp->open ("sim.vcd");
+#endif
+  // Simulate
+  while(!Verilated::gotFinish()){
+#if VM_TRACE
+      tfp->dump (main_time);
+#endif
+      main_time += 5;
+      tb->core_clk = !tb->core_clk;
+      tb->eval();
+  }
+
+#if VM_TRACE
+  tfp->close();
+#endif
+
+  std::cout << "\nVerilatorTB: End of sim" << std::endl;
+  exit(EXIT_SUCCESS);
+
+}