syscalls.c

/* Support files for GNU libc.  Files in the system namespace go here.
   Files in the C namespace (ie those that do not start with an
   underscore) go in .c.  */

#include <_ansi.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>
#include <sys/times.h>
#include <errno.h>
#include <reent.h>
#include <unistd.h>
#include <sys/wait.h>

//#undef errno
extern int errno;

//#define FreeRTOS
#define MAX_STACK_SIZE 0x200

extern int __io_putchar(int ch) __attribute__((weak));
extern int __io_getchar(void) __attribute__((weak));

#ifndef FreeRTOS
  register char * stack_ptr asm("sp");
#endif




caddr_t _sbrk(int incr)
{
    extern char end /*asm("end")*/;
    static char *heap_end;
    char *prev_heap_end,*min_stack_ptr;

    if (heap_end == 0)
        heap_end = &end;

    prev_heap_end = heap_end;

#ifdef FreeRTOS
    /* Use the NVIC offset register to locate the main stack pointer. */
    min_stack_ptr = (char*)(*(unsigned int *)*(unsigned int *)0xE000ED08);
    /* Locate the STACK bottom address */
    min_stack_ptr -= MAX_STACK_SIZE;

    if (heap_end + incr > min_stack_ptr)
#else
    if (heap_end + incr > stack_ptr)
#endif
    {
//      write(1, "Heap and stack collision\n", 25);
//      abort();
        errno = ENOMEM;
        return (caddr_t) -1;
    }

    heap_end += incr;

    return (caddr_t) prev_heap_end;
}

/*
 * _gettimeofday primitive (Stub function)
 * */
int _gettimeofday (struct timeval * tp, struct timezone * tzp)
{
  /* Return fixed data for the timezone.  */
  if (tzp)
    {
      tzp->tz_minuteswest = 0;
      tzp->tz_dsttime = 0;
    }

  return 0;
}
void initialise_monitor_handles()
{
}

int _getpid(void)
{
    return 1;
}

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

void _exit (int status)
{
    _kill(status, -1);
    while (1) {}
}

int _write(int file, char *ptr, int len)
{
    int DataIdx;

        for (DataIdx = 0; DataIdx < len; DataIdx++)
        {
           __io_putchar( *ptr++ );
        }
    return len;
}

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 _read(int file, char *ptr, int len)
{
    /* scanf calls _read() with len=1024, so eat one character at time */
    *ptr = __io_getchar();
    return 1;
}

int _open(char *path, int flags, ...)
{
    /* Pretend like we always fail */
    return -1;
}

int _wait(int *status)
{
    errno = ECHILD;
    return -1;
}

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

int _times(struct tms *buf)
{
    return -1;
}

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

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

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

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