syscalls_minimal.c

#if (USE_SYSCALLS_MINIMAL != 0)
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <time.h>
#include <sys/stat.h>

// Function declaration.
void _exit(int i);
int _open(const char *name, int flags, int mode);
int _read(int file, char *ptr, int len);
int _write(int file, char *buffer, unsigned int count);
int _lseek(int file, int ptr, int dir);
int _fstat(int file, struct stat *st);
int _link(char *old, char *new_);
int _unlink(char *name);
int _stat(char *file, struct stat *st);
int _close(int file);
int _execve(char *name, char **argv, char **env);
int _fork();
int _getpid();
int _isatty(int file);
int _kill(int pid, int sig);
int times(struct tm *buf);
int _wait(int *status);

#undef errno
extern int errno;
char *__env[1] = {0};
char **__environ = __env;

// Add dso_handle constant in case it does not exist.
// Used with shared libraries. Therefore not needed
// in an embedded system with no RTOS.
#ifndef __dso_handle
    int __dso_handle;
#endif

// Function definition.
void _exit(int i)
{
//  iprintf("Program exit with code %d", i);
    while (1);
}

int _close(int file)
{
    return -1;
}

int _fstat(int file, struct stat *st)
{
    st->st_mode = S_IFCHR;
    return 0;
}

int _isatty(int file)
{
    return 1;
}

int _lseek(int file, int ptr, int dir)
{
    return 0;
}

int _open(const char *name, int flags, int mode)
{
    return -1;
}

int _link(char *old, char *new_)
{
    errno = EMLINK;
    return -1;
}

int _unlink(char *name)
{
    errno = ENOENT;
    return -1;
}

int _stat(char *file, struct stat *st)
{
    st->st_mode = S_IFCHR;
    return 0;
}

int _execve(char *name, char **argv, char **env)
{
    errno = ENOMEM;
    return -1;
}

int _fork()
{
    errno = EAGAIN;
    return -1;
}

int _getpid()
{
    return 1;
}

int _kill(int pid, int sig)
{
    errno = EINVAL;
    return (-1);
}

int times(struct tm *buf)
{
    return -1;
}

int _wait(int *status)
{
    errno = ECHILD;
    return -1;
}
#endif // (USE_SYSCALLS_MINIMAL != 0)