/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2009 Pascal Bellard - All Rights Reserved
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *   Boston MA 02110-1301, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * ifmem.c
 *
 * Run one command if the memory is large enought, and another if it isn't.
 *
 * Usage:
 *
 *    label boot_kernel
 *        kernel ifmem.c
 *        append size_in_KB boot_large [size_in_KB boot_medium] boot_small
 *
 *    label boot_large
 *        kernel vmlinuz_large_memory
 *        append ...
 *
 *    label boot_small
 *        kernel vmlinuz_small_memory
 *        append ...
 */

#include <inttypes.h>
#include <com32.h>
#include <console.h>
#include <stdio.h>
#include <string.h>
#include <alloca.h>
#include <stdlib.h>
#include <syslinux/boot.h>

static long memory_size(void)
{
  com32sys_t ireg, oreg;

  memset(&ireg, 0, sizeof ireg);

  ireg.eax.w[0] = 0xe801;
  __intcall(0x15, &ireg, &oreg);

  return  oreg.ecx.w[0] + ( oreg.edx.w[0] << 6);
}

int main(int argc, char *argv[])
{
  char *s;
  int i;

  for (s = argv[1]; *s && (*s < '0' || *s > '9'); s++);

  if (argc < 4 || !*s) {
    openconsole(&dev_null_r, &dev_stdcon_w);
    perror("\nUsage: ifmem.c32 size_KB boot_large_memory boot_small_memory\n");
    return 1;
  }

  for (i = 1; i + 2 < argc; ) { 
    i++; // size
    if (memory_size() >= strtoul(s, NULL, 0)) break;
    s = argv[++i];
  }
  if (argv[i])
    syslinux_run_command(argv[i]);
  else
    syslinux_run_default();
  return -1;
}