Now using a truly minimalist syscalls.c
This commit is contained in:
Clifford Wolf
parent
a0d63ea588
commit
b2bcf143cb
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@ -1,447 +1,80 @@
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// An extremely minimalist syscalls.c for newlib
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// Based on riscv newlib libgloss/riscv/machine/syscall.h
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// Changes by Clifford Wolf
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//========================================================================
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// syscalls.c : Newlib operating system interface
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//========================================================================
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// This is the maven implementation of the narrow newlib operating
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// system interface. It is based on the minimum stubs in the newlib
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// documentation, the error stubs in libnosys, and the previous scale
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// implementation. Please do not include any additional system calls or
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// other functions in this file. Additional header and source files
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// should be in the machine subdirectory.
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//
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// Here is a list of the functions which make up the operating system
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// interface. The file management instructions execute syscall assembly
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// instructions so that a proxy kernel (or the simulator) can marshal up
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// the request to the host machine. The process management functions are
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// mainly just stubs since for now maven only supports a single process.
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//
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// - File management functions
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// + open : (v) open file
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// + lseek : (v) set position in file
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// + read : (v) read from file
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// + write : (v) write to file
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// + fstat : (z) status of an open file
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// + stat : (z) status of a file by name
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// + close : (z) close a file
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// + link : (z) rename a file
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// + unlink : (z) remote file's directory entry
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//
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// - Process management functions
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// + execve : (z) transfer control to new proc
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// + fork : (z) create a new process
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// + getpid : (v) get process id
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// + kill : (z) send signal to child process
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// + wait : (z) wait for a child process
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//
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// - Misc functions
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// + isatty : (v) query whether output stream is a terminal
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// + times : (z) timing information for current process
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// + sbrk : (v) increase program data space
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// + _exit : (-) exit program without cleaning up files
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//
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// There are two types of system calls. Those which return a value when
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// everything is okay (marked with (v) in above list) and those which
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// return a zero when everything is okay (marked with (z) in above
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// list). On an error (ie. when the error flag is 1) the return value is
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// always an errno which should correspond to the numbers in
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// newlib/libc/include/sys/errno.h
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//
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// Note that really I think we are supposed to define versions of these
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// functions with an underscore prefix (eg. _open). This is what some of
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// the newlib documentation says, and all the newlib code calls the
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// underscore version. This is because technically I don't think we are
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// supposed to pollute the namespace with these function names. If you
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// define MISSING_SYSCALL_NAMES in xcc/src/newlib/configure.host
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// then xcc/src/newlib/libc/include/_syslist.h will essentially define
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// all of the underscore versions to be equal to the non-underscore
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// versions. I tried not defining MISSING_SYSCALL_NAMES, and newlib
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// compiled fine but libstdc++ complained about not being able to fine
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// write, read, etc. So for now we do not use underscores (and we do
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// define MISSING_SYSCALL_NAMES).
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//
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// See the newlib documentation for more information
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// http://sourceware.org/newlib/libc.html#Syscalls
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// Written by Clifford Wolf.
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#include <sys/stat.h>
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#include <sys/times.h>
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#include <sys/time.h>
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#include <sys/timeb.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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#include <utime.h>
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#include <errno.h>
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//------------------------------------------------------------------------
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// environment
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//------------------------------------------------------------------------
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// A pointer to a list of environment variables and their values. For a
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// minimal environment, this empty list is adequate. We used to define
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// environ here but it is already defined in
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// xcc/src/newlib/libc/stdlib/environ.c so to avoid multiple definition
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// errors we have commented this out for now.
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//
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// char* __env[1] = { 0 };
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// char** environ = __env;
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//------------------------------------------------------------------------
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// open
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//------------------------------------------------------------------------
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// Open a file.
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#define UNIMPL_FUNC(_f) ".globl " #_f "\n.type " #_f ", @function\n" #_f ":\n"
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int open(const char* name, int flags, int mode)
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asm (
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".text\n"
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".align 2\n"
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UNIMPL_FUNC(open)
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UNIMPL_FUNC(openat)
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UNIMPL_FUNC(lseek)
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UNIMPL_FUNC(stat)
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UNIMPL_FUNC(lstat)
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UNIMPL_FUNC(fstatat)
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UNIMPL_FUNC(isatty)
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UNIMPL_FUNC(access)
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UNIMPL_FUNC(faccessat)
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UNIMPL_FUNC(link)
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UNIMPL_FUNC(unlink)
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UNIMPL_FUNC(execve)
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UNIMPL_FUNC(getpid)
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UNIMPL_FUNC(fork)
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UNIMPL_FUNC(kill)
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UNIMPL_FUNC(wait)
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UNIMPL_FUNC(times)
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UNIMPL_FUNC(gettimeofday)
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UNIMPL_FUNC(ftime)
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UNIMPL_FUNC(utime)
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UNIMPL_FUNC(chown)
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UNIMPL_FUNC(chmod)
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UNIMPL_FUNC(chdir)
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UNIMPL_FUNC(getcwd)
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UNIMPL_FUNC(sysconf)
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"j unimplemented_syscall\n"
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);
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void unimplemented_syscall()
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{
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errno = ENOENT;
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return -1;
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const char *p = "Unimplemented system call called!\n";
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while (*p)
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*(volatile int*)0x10000000 = *(p++);
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asm volatile ("sbreak");
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__builtin_unreachable();
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}
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//------------------------------------------------------------------------
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// openat
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//------------------------------------------------------------------------
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// Open file relative to given directory
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int openat(int dirfd, const char* name, int flags, int mode)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// lseek
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//------------------------------------------------------------------------
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// Set position in a file.
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off_t lseek(int file, off_t ptr, int dir)
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{
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errno = ESPIPE;
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return -1;
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}
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//----------------------------------------------------------------------
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// read
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//----------------------------------------------------------------------
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// Read from a file.
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ssize_t read(int file, void *ptr, size_t len)
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{
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// always EOF
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return 0;
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}
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//------------------------------------------------------------------------
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// write
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//------------------------------------------------------------------------
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// Write to a file.
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ssize_t write(int file, const void *ptr, size_t len)
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{
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unsigned int *p = (unsigned int*)0x10000000;
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const void *eptr = ptr + len;
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while (ptr != eptr)
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*p = *(char*)(ptr++);
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*(volatile int*)0x10000000 = *(char*)(ptr++);
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return len;
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}
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//------------------------------------------------------------------------
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// fstat
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//------------------------------------------------------------------------
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// Status of an open file. The sys/stat.h header file required is
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// distributed in the include subdirectory for this C library.
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int close(int file)
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{
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// close is called before _exit()
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return 0;
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}
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int fstat(int file, struct stat *st)
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{
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// fstat is called during libc startup
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// stat
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//------------------------------------------------------------------------
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// Status of a file (by name).
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int stat(const char *file, struct stat *st)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// lstat
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//------------------------------------------------------------------------
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// Status of a link (by name).
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int lstat(const char *file, struct stat *st)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// fstatat
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//------------------------------------------------------------------------
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// Status of a file (by name) in a given directory.
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int fstatat(int dirfd, const char *file, struct stat *st, int flags)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// access
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//------------------------------------------------------------------------
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// Permissions of a file (by name).
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int access(const char *file, int mode)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// faccessat
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//------------------------------------------------------------------------
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// Permissions of a file (by name) in a given directory.
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int faccessat(int dirfd, const char *file, int mode, int flags)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// close
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//------------------------------------------------------------------------
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// Close a file.
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int close(int file)
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{
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// close is always ok
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return 0;
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}
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//------------------------------------------------------------------------
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// link
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//------------------------------------------------------------------------
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// Establish a new name for an existing file.
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int link(const char *old_name, const char *new_name)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// unlink
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//------------------------------------------------------------------------
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// Remove a file's directory entry.
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int unlink(const char *name)
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{
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errno = ENOENT;
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return -1;
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}
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//------------------------------------------------------------------------
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// execve
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//------------------------------------------------------------------------
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// Transfer control to a new process. Minimal implementation for a
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// system without processes from newlib documentation.
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int execve(const char *name, char *const argv[], char *const env[])
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{
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errno = ENOMEM;
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return -1;
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}
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//------------------------------------------------------------------------
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// fork
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//------------------------------------------------------------------------
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// Create a new process. Minimal implementation for a system without
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// processes from newlib documentation.
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int fork()
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{
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errno = EAGAIN;
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return -1;
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}
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//------------------------------------------------------------------------
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// getpid
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//------------------------------------------------------------------------
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// Get process id. This is sometimes used to generate strings unlikely
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// to conflict with other processes. Minimal implementation for a
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// system without processes just returns 1.
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int getpid()
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{
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return 1;
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}
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//------------------------------------------------------------------------
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// kill
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//------------------------------------------------------------------------
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// Send a signal. Minimal implementation for a system without processes
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// just causes an error.
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int kill(int pid, int sig)
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{
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errno = EINVAL;
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return -1;
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}
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//------------------------------------------------------------------------
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// wait
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//------------------------------------------------------------------------
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// Wait for a child process. Minimal implementation for a system without
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// processes just causes an error.
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int wait(int *status)
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{
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errno = ECHILD;
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return -1;
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}
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//------------------------------------------------------------------------
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// isatty
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//------------------------------------------------------------------------
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// Query whether output stream is a terminal. For consistency with the
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// other minimal implementations, which only support output to stdout,
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// this minimal implementation is suggested by the newlib docs.
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int isatty(int file)
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{
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return 1;
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}
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//------------------------------------------------------------------------
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// times
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//------------------------------------------------------------------------
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// Timing information for current process. From
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// newlib/libc/include/sys/times.h the tms struct fields are as follows:
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//
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// - clock_t tms_utime : user clock ticks
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// - clock_t tms_stime : system clock ticks
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// - clock_t tms_cutime : children's user clock ticks
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// - clock_t tms_cstime : children's system clock ticks
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//
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// Since maven does not currently support processes we set both of the
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// children's times to zero. Eventually we might want to separately
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// account for user vs system time, but for now we just return the total
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// number of cycles since starting the program.
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clock_t times(struct tms *buf)
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{
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// when called for the first time, initialize t0
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static struct timeval t0;
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if (t0.tv_sec == 0)
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gettimeofday(&t0, 0);
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struct timeval t;
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gettimeofday(&t, 0);
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long long utime = (t.tv_sec - t0.tv_sec) * 1000000 + (t.tv_usec - t0.tv_usec);
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buf->tms_utime = utime * CLOCKS_PER_SEC / 1000000;
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buf->tms_stime = buf->tms_cstime = buf->tms_cutime = 0;
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return -1;
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}
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//----------------------------------------------------------------------
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// gettimeofday
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//----------------------------------------------------------------------
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// Get the current time. Only relatively correct.
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int gettimeofday(struct timeval *tp, void *tzp)
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{
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asm volatile ("sbreak");
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__builtin_unreachable();
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}
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//----------------------------------------------------------------------
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// ftime
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//----------------------------------------------------------------------
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// Get the current time. Only relatively correct.
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int ftime(struct timeb *tp)
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{
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tp->time = tp->millitm = 0;
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return 0;
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}
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//----------------------------------------------------------------------
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// utime
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//----------------------------------------------------------------------
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// Stub.
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int utime(const char *path, const struct utimbuf *times)
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{
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return -1;
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}
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//----------------------------------------------------------------------
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// chown
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//----------------------------------------------------------------------
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// Stub.
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int chown(const char *path, uid_t owner, gid_t group)
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{
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return -1;
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}
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//----------------------------------------------------------------------
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// chmod
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//----------------------------------------------------------------------
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// Stub.
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int chmod(const char *path, mode_t mode)
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{
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return -1;
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}
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//----------------------------------------------------------------------
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// chdir
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//----------------------------------------------------------------------
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// Stub.
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int chdir(const char *path)
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{
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return -1;
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}
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//----------------------------------------------------------------------
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// getcwd
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//----------------------------------------------------------------------
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// Stub.
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char *getcwd(char *buf, size_t size)
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{
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return NULL;
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}
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//----------------------------------------------------------------------
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// sysconf
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//----------------------------------------------------------------------
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// Get configurable system variables
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long sysconf(int name)
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{
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switch (name) {
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case _SC_CLK_TCK:
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return CLOCKS_PER_SEC;
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}
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return -1;
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}
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//----------------------------------------------------------------------
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// sbrk
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//----------------------------------------------------------------------
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// Increase program data space. As malloc and related functions depend
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// on this, it is useful to have a working implementation. The following
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// is suggested by the newlib docs and suffices for a standalone
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// system.
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void *sbrk(ptrdiff_t incr)
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{
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extern unsigned char _end[]; // Defined by linker
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@ -450,20 +83,13 @@ void *sbrk(ptrdiff_t incr)
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if (heap_end == 0)
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heap_end = (long)_end;
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// if (syscall_errno(SYS_brk, heap_end + incr, 0, 0, 0) != heap_end + incr)
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// return (void *)-1;
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heap_end += incr;
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return (void *)(heap_end - incr);
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}
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//------------------------------------------------------------------------
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// _exit
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//------------------------------------------------------------------------
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// Exit a program without cleaning up files.
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void _exit(int exit_status)
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{
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asm volatile ("sbreak");
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__builtin_unreachable();
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}
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|
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|
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@ -1,447 +1,80 @@
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// An extremely minimalist syscalls.c for newlib
|
||||
// Based on riscv newlib libgloss/riscv/machine/syscall.h
|
||||
// Changes by Clifford Wolf
|
||||
|
||||
//========================================================================
|
||||
// syscalls.c : Newlib operating system interface
|
||||
//========================================================================
|
||||
// This is the maven implementation of the narrow newlib operating
|
||||
// system interface. It is based on the minimum stubs in the newlib
|
||||
// documentation, the error stubs in libnosys, and the previous scale
|
||||
// implementation. Please do not include any additional system calls or
|
||||
// other functions in this file. Additional header and source files
|
||||
// should be in the machine subdirectory.
|
||||
//
|
||||
// Here is a list of the functions which make up the operating system
|
||||
// interface. The file management instructions execute syscall assembly
|
||||
// instructions so that a proxy kernel (or the simulator) can marshal up
|
||||
// the request to the host machine. The process management functions are
|
||||
// mainly just stubs since for now maven only supports a single process.
|
||||
//
|
||||
// - File management functions
|
||||
// + open : (v) open file
|
||||
// + lseek : (v) set position in file
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||||
// + read : (v) read from file
|
||||
// + write : (v) write to file
|
||||
// + fstat : (z) status of an open file
|
||||
// + stat : (z) status of a file by name
|
||||
// + close : (z) close a file
|
||||
// + link : (z) rename a file
|
||||
// + unlink : (z) remote file's directory entry
|
||||
//
|
||||
// - Process management functions
|
||||
// + execve : (z) transfer control to new proc
|
||||
// + fork : (z) create a new process
|
||||
// + getpid : (v) get process id
|
||||
// + kill : (z) send signal to child process
|
||||
// + wait : (z) wait for a child process
|
||||
//
|
||||
// - Misc functions
|
||||
// + isatty : (v) query whether output stream is a terminal
|
||||
// + times : (z) timing information for current process
|
||||
// + sbrk : (v) increase program data space
|
||||
// + _exit : (-) exit program without cleaning up files
|
||||
//
|
||||
// There are two types of system calls. Those which return a value when
|
||||
// everything is okay (marked with (v) in above list) and those which
|
||||
// return a zero when everything is okay (marked with (z) in above
|
||||
// list). On an error (ie. when the error flag is 1) the return value is
|
||||
// always an errno which should correspond to the numbers in
|
||||
// newlib/libc/include/sys/errno.h
|
||||
//
|
||||
// Note that really I think we are supposed to define versions of these
|
||||
// functions with an underscore prefix (eg. _open). This is what some of
|
||||
// the newlib documentation says, and all the newlib code calls the
|
||||
// underscore version. This is because technically I don't think we are
|
||||
// supposed to pollute the namespace with these function names. If you
|
||||
// define MISSING_SYSCALL_NAMES in xcc/src/newlib/configure.host
|
||||
// then xcc/src/newlib/libc/include/_syslist.h will essentially define
|
||||
// all of the underscore versions to be equal to the non-underscore
|
||||
// versions. I tried not defining MISSING_SYSCALL_NAMES, and newlib
|
||||
// compiled fine but libstdc++ complained about not being able to fine
|
||||
// write, read, etc. So for now we do not use underscores (and we do
|
||||
// define MISSING_SYSCALL_NAMES).
|
||||
//
|
||||
// See the newlib documentation for more information
|
||||
// http://sourceware.org/newlib/libc.html#Syscalls
|
||||
// Written by Clifford Wolf.
|
||||
|
||||
#include <sys/stat.h>
|
||||
#include <sys/times.h>
|
||||
#include <sys/time.h>
|
||||
#include <sys/timeb.h>
|
||||
#include <errno.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <utime.h>
|
||||
#include <errno.h>
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// environment
|
||||
//------------------------------------------------------------------------
|
||||
// A pointer to a list of environment variables and their values. For a
|
||||
// minimal environment, this empty list is adequate. We used to define
|
||||
// environ here but it is already defined in
|
||||
// xcc/src/newlib/libc/stdlib/environ.c so to avoid multiple definition
|
||||
// errors we have commented this out for now.
|
||||
//
|
||||
// char* __env[1] = { 0 };
|
||||
// char** environ = __env;
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// open
|
||||
//------------------------------------------------------------------------
|
||||
// Open a file.
|
||||
#define UNIMPL_FUNC(_f) ".globl " #_f "\n.type " #_f ", @function\n" #_f ":\n"
|
||||
|
||||
int open(const char* name, int flags, int mode)
|
||||
asm (
|
||||
".text\n"
|
||||
".align 2\n"
|
||||
UNIMPL_FUNC(open)
|
||||
UNIMPL_FUNC(openat)
|
||||
UNIMPL_FUNC(lseek)
|
||||
UNIMPL_FUNC(stat)
|
||||
UNIMPL_FUNC(lstat)
|
||||
UNIMPL_FUNC(fstatat)
|
||||
UNIMPL_FUNC(isatty)
|
||||
UNIMPL_FUNC(access)
|
||||
UNIMPL_FUNC(faccessat)
|
||||
UNIMPL_FUNC(link)
|
||||
UNIMPL_FUNC(unlink)
|
||||
UNIMPL_FUNC(execve)
|
||||
UNIMPL_FUNC(getpid)
|
||||
UNIMPL_FUNC(fork)
|
||||
UNIMPL_FUNC(kill)
|
||||
UNIMPL_FUNC(wait)
|
||||
UNIMPL_FUNC(times)
|
||||
UNIMPL_FUNC(gettimeofday)
|
||||
UNIMPL_FUNC(ftime)
|
||||
UNIMPL_FUNC(utime)
|
||||
UNIMPL_FUNC(chown)
|
||||
UNIMPL_FUNC(chmod)
|
||||
UNIMPL_FUNC(chdir)
|
||||
UNIMPL_FUNC(getcwd)
|
||||
UNIMPL_FUNC(sysconf)
|
||||
"j unimplemented_syscall\n"
|
||||
);
|
||||
|
||||
void unimplemented_syscall()
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
const char *p = "Unimplemented system call called!\n";
|
||||
while (*p)
|
||||
*(volatile int*)0x10000000 = *(p++);
|
||||
asm volatile ("sbreak");
|
||||
__builtin_unreachable();
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// openat
|
||||
//------------------------------------------------------------------------
|
||||
// Open file relative to given directory
|
||||
int openat(int dirfd, const char* name, int flags, int mode)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// lseek
|
||||
//------------------------------------------------------------------------
|
||||
// Set position in a file.
|
||||
|
||||
off_t lseek(int file, off_t ptr, int dir)
|
||||
{
|
||||
errno = ESPIPE;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// read
|
||||
//----------------------------------------------------------------------
|
||||
// Read from a file.
|
||||
|
||||
ssize_t read(int file, void *ptr, size_t len)
|
||||
{
|
||||
// always EOF
|
||||
return 0;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// write
|
||||
//------------------------------------------------------------------------
|
||||
// Write to a file.
|
||||
|
||||
ssize_t write(int file, const void *ptr, size_t len)
|
||||
{
|
||||
unsigned int *p = (unsigned int*)0x10000000;
|
||||
const void *eptr = ptr + len;
|
||||
while (ptr != eptr)
|
||||
*p = *(char*)(ptr++);
|
||||
*(volatile int*)0x10000000 = *(char*)(ptr++);
|
||||
return len;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// fstat
|
||||
//------------------------------------------------------------------------
|
||||
// Status of an open file. The sys/stat.h header file required is
|
||||
// distributed in the include subdirectory for this C library.
|
||||
int close(int file)
|
||||
{
|
||||
// close is called before _exit()
|
||||
return 0;
|
||||
}
|
||||
|
||||
int fstat(int file, struct stat *st)
|
||||
{
|
||||
// fstat is called during libc startup
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// stat
|
||||
//------------------------------------------------------------------------
|
||||
// Status of a file (by name).
|
||||
|
||||
int stat(const char *file, struct stat *st)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// lstat
|
||||
//------------------------------------------------------------------------
|
||||
// Status of a link (by name).
|
||||
|
||||
int lstat(const char *file, struct stat *st)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// fstatat
|
||||
//------------------------------------------------------------------------
|
||||
// Status of a file (by name) in a given directory.
|
||||
|
||||
int fstatat(int dirfd, const char *file, struct stat *st, int flags)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// access
|
||||
//------------------------------------------------------------------------
|
||||
// Permissions of a file (by name).
|
||||
|
||||
int access(const char *file, int mode)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// faccessat
|
||||
//------------------------------------------------------------------------
|
||||
// Permissions of a file (by name) in a given directory.
|
||||
|
||||
int faccessat(int dirfd, const char *file, int mode, int flags)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// close
|
||||
//------------------------------------------------------------------------
|
||||
// Close a file.
|
||||
|
||||
int close(int file)
|
||||
{
|
||||
// close is always ok
|
||||
return 0;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// link
|
||||
//------------------------------------------------------------------------
|
||||
// Establish a new name for an existing file.
|
||||
|
||||
int link(const char *old_name, const char *new_name)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// unlink
|
||||
//------------------------------------------------------------------------
|
||||
// Remove a file's directory entry.
|
||||
|
||||
int unlink(const char *name)
|
||||
{
|
||||
errno = ENOENT;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// execve
|
||||
//------------------------------------------------------------------------
|
||||
// Transfer control to a new process. Minimal implementation for a
|
||||
// system without processes from newlib documentation.
|
||||
|
||||
int execve(const char *name, char *const argv[], char *const env[])
|
||||
{
|
||||
errno = ENOMEM;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// fork
|
||||
//------------------------------------------------------------------------
|
||||
// Create a new process. Minimal implementation for a system without
|
||||
// processes from newlib documentation.
|
||||
|
||||
int fork()
|
||||
{
|
||||
errno = EAGAIN;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// getpid
|
||||
//------------------------------------------------------------------------
|
||||
// Get process id. This is sometimes used to generate strings unlikely
|
||||
// to conflict with other processes. Minimal implementation for a
|
||||
// system without processes just returns 1.
|
||||
|
||||
int getpid()
|
||||
{
|
||||
return 1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// kill
|
||||
//------------------------------------------------------------------------
|
||||
// Send a signal. Minimal implementation for a system without processes
|
||||
// just causes an error.
|
||||
|
||||
int kill(int pid, int sig)
|
||||
{
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// wait
|
||||
//------------------------------------------------------------------------
|
||||
// Wait for a child process. Minimal implementation for a system without
|
||||
// processes just causes an error.
|
||||
|
||||
int wait(int *status)
|
||||
{
|
||||
errno = ECHILD;
|
||||
return -1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// isatty
|
||||
//------------------------------------------------------------------------
|
||||
// Query whether output stream is a terminal. For consistency with the
|
||||
// other minimal implementations, which only support output to stdout,
|
||||
// this minimal implementation is suggested by the newlib docs.
|
||||
|
||||
int isatty(int file)
|
||||
{
|
||||
return 1;
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// times
|
||||
//------------------------------------------------------------------------
|
||||
// Timing information for current process. From
|
||||
// newlib/libc/include/sys/times.h the tms struct fields are as follows:
|
||||
//
|
||||
// - clock_t tms_utime : user clock ticks
|
||||
// - clock_t tms_stime : system clock ticks
|
||||
// - clock_t tms_cutime : children's user clock ticks
|
||||
// - clock_t tms_cstime : children's system clock ticks
|
||||
//
|
||||
// Since maven does not currently support processes we set both of the
|
||||
// children's times to zero. Eventually we might want to separately
|
||||
// account for user vs system time, but for now we just return the total
|
||||
// number of cycles since starting the program.
|
||||
|
||||
clock_t times(struct tms *buf)
|
||||
{
|
||||
// when called for the first time, initialize t0
|
||||
static struct timeval t0;
|
||||
if (t0.tv_sec == 0)
|
||||
gettimeofday(&t0, 0);
|
||||
|
||||
struct timeval t;
|
||||
gettimeofday(&t, 0);
|
||||
|
||||
long long utime = (t.tv_sec - t0.tv_sec) * 1000000 + (t.tv_usec - t0.tv_usec);
|
||||
buf->tms_utime = utime * CLOCKS_PER_SEC / 1000000;
|
||||
buf->tms_stime = buf->tms_cstime = buf->tms_cutime = 0;
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// gettimeofday
|
||||
//----------------------------------------------------------------------
|
||||
// Get the current time. Only relatively correct.
|
||||
|
||||
int gettimeofday(struct timeval *tp, void *tzp)
|
||||
{
|
||||
asm volatile ("sbreak");
|
||||
__builtin_unreachable();
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// ftime
|
||||
//----------------------------------------------------------------------
|
||||
// Get the current time. Only relatively correct.
|
||||
|
||||
int ftime(struct timeb *tp)
|
||||
{
|
||||
tp->time = tp->millitm = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// utime
|
||||
//----------------------------------------------------------------------
|
||||
// Stub.
|
||||
|
||||
int utime(const char *path, const struct utimbuf *times)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// chown
|
||||
//----------------------------------------------------------------------
|
||||
// Stub.
|
||||
|
||||
int chown(const char *path, uid_t owner, gid_t group)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// chmod
|
||||
//----------------------------------------------------------------------
|
||||
// Stub.
|
||||
|
||||
int chmod(const char *path, mode_t mode)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// chdir
|
||||
//----------------------------------------------------------------------
|
||||
// Stub.
|
||||
|
||||
int chdir(const char *path)
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// getcwd
|
||||
//----------------------------------------------------------------------
|
||||
// Stub.
|
||||
|
||||
char *getcwd(char *buf, size_t size)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// sysconf
|
||||
//----------------------------------------------------------------------
|
||||
// Get configurable system variables
|
||||
|
||||
long sysconf(int name)
|
||||
{
|
||||
switch (name) {
|
||||
case _SC_CLK_TCK:
|
||||
return CLOCKS_PER_SEC;
|
||||
}
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
//----------------------------------------------------------------------
|
||||
// sbrk
|
||||
//----------------------------------------------------------------------
|
||||
// Increase program data space. As malloc and related functions depend
|
||||
// on this, it is useful to have a working implementation. The following
|
||||
// is suggested by the newlib docs and suffices for a standalone
|
||||
// system.
|
||||
|
||||
void *sbrk(ptrdiff_t incr)
|
||||
{
|
||||
extern unsigned char _end[]; // Defined by linker
|
||||
|
|
@ -450,20 +83,13 @@ void *sbrk(ptrdiff_t incr)
|
|||
if (heap_end == 0)
|
||||
heap_end = (long)_end;
|
||||
|
||||
// if (syscall_errno(SYS_brk, heap_end + incr, 0, 0, 0) != heap_end + incr)
|
||||
// return (void *)-1;
|
||||
|
||||
heap_end += incr;
|
||||
return (void *)(heap_end - incr);
|
||||
}
|
||||
|
||||
//------------------------------------------------------------------------
|
||||
// _exit
|
||||
//------------------------------------------------------------------------
|
||||
// Exit a program without cleaning up files.
|
||||
|
||||
void _exit(int exit_status)
|
||||
{
|
||||
asm volatile ("sbreak");
|
||||
__builtin_unreachable();
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue