springbok/springbok_gloss.c

#include <errno.h>
#include <sys/stat.h>
#include <unistd.h>

#include <springbok_intrinsics.h>

void _exit(int rc) {
  springbok_finish();

  while (1) { }
}

void *_sbrk(int nbytes) {
  extern int _sheap, _eheap;
  static void *_heap_ptr = (void *)&_sheap;
  if ((void*)&_eheap >= _heap_ptr + nbytes) {
    void *base = _heap_ptr;
    _heap_ptr += nbytes;
    return base;
  } else {
    errno = ENOMEM;
    return (void *)-1;
  }
}

int _read(int file, char *ptr, int len) {
  if (file != STDIN_FILENO) {
    errno = EBADF;
    return -1;
  }

  return 0;
}


int _write(int file, char *buf, int nbytes) {
  static int _write_line_buffer_len[2] = {0, 0};
  static char _write_line_buffer[2][256];

  if (file != STDOUT_FILENO && file != STDERR_FILENO) {
    errno = EBADF;
    return -1;
  }

  if (nbytes == 0) {
    return 0;
  }

  if (buf == NULL) {
    errno = EFAULT;
    return -1;
  }

  const int buffer_num   = (file == STDOUT_FILENO)? 0 : 1;
  const int buffer_level = (file == STDOUT_FILENO)? SPRINGBOK_SIMPRINT_INFO : SPRINGBOK_SIMPRINT_ERROR;

  char c;
  do {
    c = *(buf++);
    if (c == '\n') {
      _write_line_buffer[buffer_num][_write_line_buffer_len[buffer_num]] = '\0';
      springbok_simprint(buffer_level, _write_line_buffer[buffer_num], buffer_num);
      _write_line_buffer_len[buffer_num] = 0;
    } else if (c != '\0') {
      _write_line_buffer[buffer_num][_write_line_buffer_len[buffer_num]] = c;
      _write_line_buffer_len[buffer_num]++;
      if (_write_line_buffer_len[buffer_num] == 255) {
        _write_line_buffer[buffer_num][_write_line_buffer_len[buffer_num]] = '\0';
        springbok_simprint(buffer_level, _write_line_buffer[buffer_num], buffer_num);
        _write_line_buffer_len[buffer_num] = 0;
      }
    }
  } while(c != '\0');

  return nbytes;
}

int _close(int file) {
  errno = EBADF;
  return -1;
}

int _lseek(int file, int offset, int whence) {
  if (file != STDOUT_FILENO && file != STDERR_FILENO) {
    errno = EBADF;
    return -1;
  }

  return 0;
}

int _fstat(int file, struct stat *st) {
  if (file != STDOUT_FILENO && file != STDERR_FILENO) {
    errno = EBADF;
    return -1;
  }

  if (st == NULL) {
    errno = EFAULT;
    return -1;
  }

  st->st_mode = S_IFCHR;
  return 0;
}

int _isatty(int file) {
  if (file != STDOUT_FILENO && file != STDERR_FILENO) {
    errno = EBADF;
    return -1;
  }

  return 1;
}