quasar/README.md

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2021-03-30 14:09:40 +08:00
# Quasar RISC-V Core 2.0 from Lampro Mellon
This repository contains the Quasar Core design in CHISEL.
## License
By contributing to this project, you agree that your contribution is governed by [Apache-2.0](LICENSE).
Files under the [tools](tools/) directory may be available under a different license. Please review individual file for details.
## Background
Quasar is a Chiselified version of EL2 SweRV RISC-V Core.
## Directory Structure
├── configs # Configurations dir
├── design
│ ├── project
│ ├── project
│ └── target
│ ├── snapshots
│ └── default # Where generated configuration files are created
│ ├── src
│ ├── main
│ ├── resources
│ └── vsrc # Blackbox files dir
│ └── scala # Design root dir
│ ├── dbg # Debugger
│ ├── dec # Decode, Registers and Exceptions
│ ├── dmi # DMI block
│ ├── exu # EXU (ALU/MUL/DIV)
│ ├── ifu # Fetch & Branch Prediction
│ ├── include # Bundles file
│ ├── lib # Bridges and Library
│ └── lsu # Load/Store
│ └── test
│ ├── target
│ └── test_run_dir
├── doc # PPA Report
├── generated_rtl # Quasar wrapper
├── testbench
│ ├── asm # Example assembly files
│ ├── hex # Canned demo hex files
│ └── tests # Example tests
├── tools # Scripts/Makefiles
├── tracer_logs # generated log files
└── verif
├── LEC
├── formality_work
└── formality_log # LEC log files
└── setup_files # user_match files
└── sim # Simulation log/dump files
## Dependencies
- Verilator **(4.102 or later)** must be installed on the system if running with verilator.
- Vcs must be installed on the system if running with vcs.
- RISCV tool chain (based on gcc version 8.3 or higher) must be
installed so that it can be used to prepare RISCV binaries to run.
- Sbt **(1.3.13 or later)** must be installed on the system.
## Quickstart guide
1. Clone the repository
2. Setup RV_ROOT to point to the path in your local filesystem
3. Determine your configuration {optional}
4. Run make with $RV_ROOT/tools/Makefile
## Release Notes for this version
Please see [release-notes](release-notes.md) for changes and bug fixes in this version of Quasar.
### Configurations
Quasar can be configured by running the script:
```
$RV_ROOT/configs/quasar.config
```
For detailed help options.
```
$RV_ROOT/configs/quasar.config -h
```
For example, to build with a DCCM of size 64Kb:
```
$RV_ROOT/configs/quasar.config -dccm_size=64
```
This will update the **default** snapshot in `$RV_ROOT/design/snapshots/default/` with parameters for a 64K DCCM.
Add `-snapshot=dccm64`, for example, if you wish to name your build snapshot *dccm64* and refer to it during the build.
There are 4 predefined target configurations: `default`, `default_ahb`, `typical_pd` and `high_perf` that can be selected via the `-target=name` option to quasar.config.
This script derives the following consistent set of include files :
```
$RV_ROOT/design/snapshots/default
├── common_defines.vh # `defines for testbench or design
├── defines.h # defines for C/assembly headers
├── param.vh # Design parameters
├── pdef.vh # Parameter structure
├── pd_defines.vh # `defines for physical design
├── perl_configs.pl # Perl %configs hash for scripting
├── pic_map_auto.h # PIC memory map based on configure size
├── whisper.json # JSON file for swerv-iss
└── link.ld # default linker control file
```
#### 1. Generate scala parameter
```
make -f $RV_ROOT/tools/Makefile conf
```
This script will run `quasar.config` and derives the include file:
```
$RV_ROOT/design/src/main/scala/lib
└── param.scala # Scala design parameters
```
### Running RTL Simulation
while in a work directory:
#### 1. Set the RV_ROOT environment variable to the root of the Quasar directory structure.
Example for bash shell:
```
export RV_ROOT=$(pwd)
```
Example for csh or its derivatives:
```
setenv RV_ROOT /path/to/QUASAR
```
#### 2. Create your specific configuration
*(Skip if default is sufficient)*
*(Name your snapshot to distinguish it from the default. Without an explicit name, it will update/override the __default__ snapshot)*. For example, if `mybuild` is the name for the snapshot:
set BUILD_PATH environment variable:
```
setenv BUILD_PATH snapshots/mybuild
$RV_ROOT/configs/quasar.config [configuration options..] -snapshot=mybuild
```
Snapshots are placed in `$BUILD_PATH` directory.
#### 3. Run sbt
```
make -f $RV_ROOT/tools/Makefile sbt_
```
This command will generate the Quasar wrapper in system verilog of Quasar chisel, in the `generated_rtl` directory and runs the `reset_script.py`
* In the reset_script we do a post verilog-generation changes, these changes are as follows:
* Replace `posedge reset` with `negedge reset`
* Replace `if (reset)` with `if (~reset)`
#### 4. Running a simple Hello World program (verilator)
```
make -f $RV_ROOT/tools/Makefile
```
This command will build a verilator model of Quasar with AXI bus, and execute a short sequence of instructions that writes out "HELLO WORLD"
to the bus.
The simulation produces output on the screen like:
```
VerilatorTB: Start of sim
----------------------------------
Hello World from QUASAR @LMDC !!
----------------------------------
TEST_PASSED
Finished : minstret = 437, mcycle = 922
See "exec.log" for execution trace with register updates..
```
The simulation generates following files in `$RV_ROOT/verif/sim`:
`console.log` contains what the cpu writes to the console address of 0xd0580000.
`exec.log` shows instruction trace with GPR updates.
`trace_port.csv` contains a log of the trace port.
Other log files are `dec.log`, `exu.log`, `ifu.log`, `lsu.log` and `pic.log`, generates in `$RV_ROOT/tracer_logs`.
When `debug=1` is provided, a vcd file `sim.vcd` is created and can be browsed by gtkwave or similar waveform viewers.
You can re-execute simulation using:
```
make -f $RV_ROOT/tools/Makefile verilator
```
#### 5. Default for VCS/Verilotor
If you want to run default configuration on verilator use the following command
```
make -f $RV_ROOT/tools/Makefile
```
For VCS use
```
make -f $RV_ROOT/tools/Makefile vcs_all
```
The simulation run/build command has following generic form:
```
make -f $RV_ROOT/tools/Makefile [<simulator>] [debug=1] [snapshot=mybuild] [target=<target>] [TEST=<test>] [TEST_DIR=<path_to_test_dir>]
```
where:
```
<simulator> - can be 'verilator' (by default) , 'vcs' - Synopsys VCS, 'riviera'- Aldec Riviera-PRO. If not provided, 'make' cleans work directory, builds verilator executable and runs a test.
debug=1 - allows VCD generation for verilator and VCS and SHM waves for irun option.
<target> - predefined CPU configurations 'default' ( by default), 'default_ahb', 'typical_pd', 'high_perf'.
TEST - allows to run a C (<test>.c) or assembly (<test>.s) test, hello_world is run by default.
TEST_DIR - alternative to test source directory testbench/asm or testbench/tests.
<snapshot> - run and build executable model of custom CPU configuration, remember to provide 'snapshot' argument for runs on custom configurations.
CONF_PARAMS - allows to provide -set options to quasar.conf script to alter predefined targets parameters.
```
Example:
```
make -f $RV_ROOT/tools/Makefile verilator TEST=cmark
```
will build and simulate `testbench/asm/cmark.c` program with verilator.
If you want to compile a test only, you can run:
```
make -f $RV_ROOT/tools/Makefile program.hex TEST=<test> [TEST_DIR=/path/to/dir]
```
The Makefile uses `snapshot/<target>/link.ld` file, generated by quasar.conf script by default to build test executable. User can provide test specific linker file in form `<test_name>.ld` to build the test executable, in the same directory with the test source.
User also can create a test specific makefile in form `<test_name>.makefile`, containing building instructions how to create `program.hex` file used by simulation. The private makefile should be in the same directory as the test source. See examples in `testbench/asm` directory.
*(`program.hex` file is loaded to instruction and LSU bus memory slaves and optionally to DCCM/ICCM at the beginning of simulation)*.
User can build `program.hex` file by any other means and then run simulation with following command:
make -f $RV_ROOT/tools/Makefile <simulator>
Note: You may need to delete `program.hex` file from work directory, when run a new test.
The `$RV_ROOT/testbench/asm` directory contains following tests ready to simulate:
```
hello_world - default test program to run, prints Hello World message to screen and console.log
hello_world_dccm - the same as above, but takes the string from preloaded DCCM.
hello_world_iccm - the same as hello_world, but loads the test code to ICCM via LSU to DMA bridge and then executes it from there. Runs on QUASAR with AXI4 buses only.
cmark - coremark benchmark running with code and data in external memories
cmark_dccm - the same as above, running data and stack from DCCM (faster)
cmark_iccm - the same as above with preloaded code to ICCM.
dhry - Run dhrystone. (Scale by 1757 to get DMIPS/MHZ)
```
The `$RV_ROOT/testbench/hex` directory contains precompiled hex files of the tests, ready for simulation in case RISCV SW tools are not installed.
#### 6. Logical Equivalence Checking of Quasar
If you want to perform LEC on quasar, use the following command
```
make -f $RV_ROOT/tools/Makefile lec
```
This command will call the LEC Makefile to clone Quasar along with the SweRV-EL2 and run `sbt` for chisel-generated RTL. Then, this will take file for user-match the ports, blockbox pins, latches, flops and perform the LEC of Quasar.
Following log files are created in `$RV_ROOT/verif/LEC/formality_work/formality_log` :
`fm_shell_command.log` gives the detail of instructions
`formality.log` gives the detail of undriven nets
**Note**: The testbench has a simple synthesizable bridge that allows you to load the ICCM via load/store instructions. This is only supported for AXI4 builds.