#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>


int
main (int argc, char *argv[])
{
  int file;
  off_t offset;
  char bootable[2] = { 0x55, 0xaa };

  if (argc < 2)
    error (1, 0, "Usage: make-it-bootable disk-image.");

  file = open (argv[1], O_WRONLY);
  if (file < 0)
    error (1, errno, "Failed");

  offset = lseek (file, 0x1fe, SEEK_SET);
  if (offset != 0x1fe)
    error (1, 0, "Offset %u", offset);

  write (file, bootable, sizeof (bootable));
  close (file);

  return 0;
}