builtins.c

i386的bootloader源码grub

  errnum = ERR_UNRECOGNIZED;
  return 1;
  
#else /* ! GRUB_UTIL */
  
  unsigned short *port;
  
  /* Get the drive number.  */
  set_device (arg);
  if (errnum)
    return 1;

  /* Clean out IO_MAP.  */
  grub_memset ((char *) io_map, 0, IO_MAP_SIZE * sizeof (unsigned short));

  /* Track the int13 handler.  */
  track_int13 (current_drive);
  
  /* Print out the result.  */
  for (port = io_map; *port != 0; port++)
    grub_printf (" 0x%x", (unsigned int) *port);

  return 0;
  
#endif /* ! GRUB_UTIL */
}

static struct builtin builtin_ioprobe =
{
  "ioprobe",
  ioprobe_func,
  BUILTIN_CMDLINE,
  "ioprobe DRIVE",
  "Probe I/O ports used for the drive DRIVE."
};


/* kernel */
static int
kernel_func (char *arg, int flags)
{
  int len;
  kernel_t suggested_type = KERNEL_TYPE_NONE;
  unsigned long load_flags = 0;

#ifndef AUTO_LINUX_MEM_OPT
  load_flags |= KERNEL_LOAD_NO_MEM_OPTION;
#endif

  /* Deal with GNU-style long options.  */
  while (1)
    {
      /* If the option `--type=TYPE' is specified, convert the string to
	 a kernel type.  */
      if (grub_memcmp (arg, "--type=", 7) == 0)
	{
	  arg += 7;
	  
	  if (grub_memcmp (arg, "netbsd", 6) == 0)
	    suggested_type = KERNEL_TYPE_NETBSD;
	  else if (grub_memcmp (arg, "freebsd", 7) == 0)
	    suggested_type = KERNEL_TYPE_FREEBSD;
	  else if (grub_memcmp (arg, "openbsd", 7) == 0)
	    /* XXX: For now, OpenBSD is identical to NetBSD, from GRUB's
	       point of view.  */
	    suggested_type = KERNEL_TYPE_NETBSD;
	  else if (grub_memcmp (arg, "linux", 5) == 0)
	    suggested_type = KERNEL_TYPE_LINUX;
	  else if (grub_memcmp (arg, "biglinux", 8) == 0)
	    suggested_type = KERNEL_TYPE_BIG_LINUX;
	  else if (grub_memcmp (arg, "multiboot", 9) == 0)
	    suggested_type = KERNEL_TYPE_MULTIBOOT;
	  else
	    {
	      errnum = ERR_BAD_ARGUMENT;
	      return 1;
	    }
	}
      /* If the `--no-mem-option' is specified, don't pass a Linux's mem
	 option automatically. If the kernel is another type, this flag
	 has no effect.  */
      else if (grub_memcmp (arg, "--no-mem-option", 15) == 0)
	load_flags |= KERNEL_LOAD_NO_MEM_OPTION;
      else
	break;

      /* Try the next.  */
      arg = skip_to (0, arg);
    }
      
  len = grub_strlen (arg);

  /* Reset MB_CMDLINE.  */
  mb_cmdline = (char *) MB_CMDLINE_BUF;
  if (len + 1 > MB_CMDLINE_BUFLEN)
    {
      errnum = ERR_WONT_FIT;
      return 1;
    }

  /* Copy the command-line to MB_CMDLINE.  */
  grub_memmove (mb_cmdline, arg, len + 1);
  kernel_type = load_image (arg, mb_cmdline, suggested_type, load_flags);
  if (kernel_type == KERNEL_TYPE_NONE)
    return 1;

  mb_cmdline += len + 1;
  return 0;
}

static struct builtin builtin_kernel =
{
  "kernel",
  kernel_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "kernel [--no-mem-option] [--type=TYPE] FILE [ARG ...]",
  "Attempt to load the primary boot image from FILE. The rest of the"
  " line is passed verbatim as the \"kernel command line\".  Any modules"
  " must be reloaded after using this command. The option --type is used"
  " to suggest what type of kernel to be loaded. TYPE must be either of"
  " \"netbsd\", \"freebsd\", \"openbsd\", \"linux\", \"biglinux\" and"
  " \"multiboot\". The option --no-mem-option tells GRUB not to pass a"
  " Linux's mem option automatically."
};


/* lock */
static int
lock_func (char *arg, int flags)
{
  if (! auth && password)
    {
      errnum = ERR_PRIVILEGED;
      return 1;
    }

  return 0;
}

static struct builtin builtin_lock =
{
  "lock",
  lock_func,
  BUILTIN_CMDLINE,
  "lock",
  "Break a command execution unless the user is authenticated."
};
  

/* makeactive */
static int
makeactive_func (char *arg, int flags)
{
  if (! make_saved_active ())
    return 1;

  return 0;
}

static struct builtin builtin_makeactive =
{
  "makeactive",
  makeactive_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "makeactive",
  "Set the active partition on the root disk to GRUB's root device."
  " This command is limited to _primary_ PC partitions on a hard disk."
};


/* map */
/* Map FROM_DRIVE to TO_DRIVE.  */
static int
map_func (char *arg, int flags)
{
  char *to_drive;
  char *from_drive;
  unsigned long to, from;
  int i;
  
  to_drive = arg;
  from_drive = skip_to (0, arg);

  /* Get the drive number for TO_DRIVE.  */
  set_device (to_drive);
  if (errnum)
    return 1;
  to = current_drive;

  /* Get the drive number for FROM_DRIVE.  */
  set_device (from_drive);
  if (errnum)
    return 1;
  from = current_drive;

  /* Search for an empty slot in BIOS_DRIVE_MAP.  */
  for (i = 0; i < DRIVE_MAP_SIZE; i++)
    {
      /* Perhaps the user wants to override the map.  */
      if ((bios_drive_map[i] & 0xff) == from)
	break;
      
      if (! bios_drive_map[i])
	break;
    }

  if (i == DRIVE_MAP_SIZE)
    {
      errnum = ERR_WONT_FIT;
      return 1;
    }

  if (to == from)
    /* If TO is equal to FROM, delete the entry.  */
    grub_memmove ((char *) &bios_drive_map[i], (char *) &bios_drive_map[i + 1],
		  sizeof (unsigned short) * (DRIVE_MAP_SIZE - i));
  else
    bios_drive_map[i] = from | (to << 8);
  
  return 0;
}

static struct builtin builtin_map =
{
  "map",
  map_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "map TO_DRIVE FROM_DRIVE",
  "Map the drive FROM_DRIVE to the drive TO_DRIVE. This is necessary"
  " when you chain-load some operating systems, such as DOS, if such an"
  " OS resides at a non-first drive."
};


#ifdef USE_MD5_PASSWORDS
/* md5crypt */
static int
md5crypt_func (char *arg, int flags)
{
  char crypted[36];
  char key[32];
  unsigned int seed;
  int i;
  const char *const seedchars =
    "./0123456789ABCDEFGHIJKLMNOPQRST"
    "UVWXYZabcdefghijklmnopqrstuvwxyz";
  
  /* First create a salt.  */

  /* The magical prefix.  */
  grub_memset (crypted, 0, sizeof (crypted));
  grub_memmove (crypted, "$1$", 3);

  /* Create the length of a salt.  */
  seed = currticks ();

  /* Generate a salt.  */
  for (i = 0; i < 8 && seed; i++)
    {
      /* FIXME: This should be more random.  */
      crypted[3 + i] = seedchars[seed & 0x3f];
      seed >>= 6;
    }

  /* A salt must be terminated with `$', if it is less than 8 chars.  */
  crypted[3 + i] = '$';

#ifdef DEBUG_MD5CRYPT
  grub_printf ("salt = %s\n", crypted);
#endif
  
  /* Get a password.  */
  grub_memset (key, 0, sizeof (key));
  get_cmdline ("Password: ", key, sizeof (key) - 1, '*', 0);

  /* Crypt the key.  */
  make_md5_password (key, crypted);

  grub_printf ("Encrypted: %s\n", crypted);
  return 0;
}

static struct builtin builtin_md5crypt =
{
  "md5crypt",
  md5crypt_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "md5crypt",
  "Generate a password in MD5 format."
};
#endif /* USE_MD5_PASSWORDS */


/* module */
static int
module_func (char *arg, int flags)
{
  int len = grub_strlen (arg);

  switch (kernel_type)
    {
    case KERNEL_TYPE_MULTIBOOT:
      if (mb_cmdline + len + 1 > (char *) MB_CMDLINE_BUF + MB_CMDLINE_BUFLEN)
	{
	  errnum = ERR_WONT_FIT;
	  return 1;
	}
      grub_memmove (mb_cmdline, arg, len + 1);
      if (! load_module (arg, mb_cmdline))
	return 1;
      mb_cmdline += len + 1;
      break;

    case KERNEL_TYPE_LINUX:
    case KERNEL_TYPE_BIG_LINUX:
      if (! load_initrd (arg))
	return 1;
      break;

    default:
      errnum = ERR_NEED_MB_KERNEL;
      return 1;
    }

  return 0;
}

static struct builtin builtin_module =
{
  "module",
  module_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "module FILE [ARG ...]",
  "Load a boot module FILE for a Multiboot format boot image (no"
  " interpretation of the file contents is made, so users of this"
  " command must know what the kernel in question expects). The"
  " rest of the line is passed as the \"module command line\", like"
  " the `kernel' command."
};


/* modulenounzip */
static int
modulenounzip_func (char *arg, int flags)
{
  int ret;

#ifndef NO_DECOMPRESSION
  no_decompression = 1;
#endif

  ret = module_func (arg, flags);

#ifndef NO_DECOMPRESSION
  no_decompression = 0;
#endif

  return ret;
}

static struct builtin builtin_modulenounzip =
{
  "modulenounzip",
  modulenounzip_func,
  BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
  "modulenounzip FILE [ARG ...]",
  "The same as `module', except that automatic decompression is"
  " disabled."
};


/* pager [on|off] */
static int
pager_func (char *arg, int flags)
{
  /* If ARG is empty, toggle the flag.  */
  if (! *arg)
    use_pager = ! use_pager;
  else if (grub_memcmp (arg, "on", 2) == 0)
    use_pager = 1;
  else if (grub_memcmp (arg, "off", 3) == 0)
    use_pager = 0;
  else
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }

  grub_printf (" Internal pager is now %s\n", use_pager ? "on" : "off");
  return 0;
}

static struct builtin builtin_pager =
{
  "pager",
  pager_func,
  BUILTIN_CMDLINE | BUILTIN_MENU | BUILTIN_HELP_LIST,
  "pager [FLAG]",
  "Toggle pager mode with no argument. If FLAG is given and its value"
  " is `on', turn on the mode. If FLAG is `off', turn off the mode."
};


/* partnew PART TYPE START LEN */
static int
partnew_func (char *arg, int flags)
{
  int new_type, new_start, new_len;
  int start_cl, start_ch, start_dh;
  int end_cl, end_ch, end_dh;
  int entry;
  char mbr[512];

  /* Convert a LBA address to a CHS address in the INT 13 format.  */
  auto void lba_to_chs (int lba, int *cl, int *ch, int *dh);
  void lba_to_chs (int lba, int *cl, int *ch, int *dh)
    {
      int cylinder, head, sector;

      sector = lba % buf_geom.sectors + 1;
      head = (lba / buf_geom.sectors) % buf_geom.heads;
      cylinder = lba / (buf_geom.sectors * buf_geom.heads);

      if (cylinder >= buf_geom.cylinders)
	cylinder = buf_geom.cylinders - 1;
      
      *cl = sector | ((cylinder & 0x300) >> 2);
      *ch = cylinder & 0xFF;
      *dh = head;
    }
      
  /* Get the drive and the partition.  */
  if (! set_device (arg))
    return 1;

  /* The drive must be a hard disk.  */
  if (! (current_drive & 0x80))
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }

  /* The partition must a primary partition.  */
  if ((current_partition >> 16) > 3
      || (current_partition & 0xFFFF) != 0xFFFF)
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }

  entry = current_partition >> 16;
  
  /* Get the new partition type.  */
  arg = skip_to (0, arg);
  if (! safe_parse_maxint (&arg, &new_type))
    return 1;

  /* The partition type is unsigned char.  */
  if (new_type > 0xFF)
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }

  /* Get the new partition start.  */
  arg = skip_to (0, arg);
  if (! safe_parse_maxint (&arg, &new_start))
    return 1;
  
  /* Get the new partition length.  */
  arg = skip_to (0, arg);
  if (! safe_parse_maxint (&arg, &new_len))
    return 1;

  /* Read the MBR.  */
  if (! rawread (current_drive, 0, 0, SECTOR_SIZE, mbr))
    return 1;

  /* Check if the new partition will fit in the disk.  */
  if (new_start + new_len > buf_geom.total_sectors)
    {
      errnum = ERR_GEOM;
      return 1;
    }

  /* Store the partition information in the MBR.  */
  lba_to_chs (new_start, &start_cl, &start_ch, &start_dh);
  lba_to_chs (new_start + new_len - 1, &end_cl, &end_ch, &end_dh);

  PC_SLICE_FLAG (mbr, entry) = 0;
  PC_SLICE_HEAD (mbr, entry) = start_dh;
  PC_SLICE_SEC (mbr, entry) = start_cl;
  PC_SLICE_CYL (mbr, entry) = start_ch;
  PC_SLICE_TYPE (mbr, entry) = new_type;
  PC_SLICE_EHEAD (mbr, entry) = end_dh;
  PC_SLICE_ESEC (mbr, entry) = end_cl;
  PC_SLICE_ECYL (mbr, entry) = end_ch;
  PC_SLICE_START (mbr, entry) = new_start;
  PC_SLICE_LENGTH (mbr, entry) = new_len;

  /* Make sure that the MBR has a valid signature.  */
  PC_MBR_SIG (mbr) = PC_MBR_SIGNATURE;
  
  /* Write back the MBR to the disk.  */
  buf_track = -1;
  if (! rawwrite (current_drive, 0, mbr))
    return 1;

  return 0;
}

static struct builtin builtin_partnew =
{
  "partnew",
  partnew_func,
  BUILTIN_CMDLINE | BUILTIN_MENU | BUILTIN_HELP_LIST,
  "partnew PART TYPE START LEN",
  "Create a primary partition at the starting address START with the"
  " length LEN, with the type TYPE. START and LEN are in sector units."
};


/* parttype PART TYPE */
static int
parttype_func (char *arg, int flags)
{
  int new_type;
  unsigned long part = 0xFFFFFF;
  unsigned long start, len, offset, ext_offset;
  int entry, type;
  char mbr[512];

  /* Get the drive and the partition.  */
  if (! set_device (arg))
    return 1;

  /* The drive must be a hard disk.  */
  if (! (current_drive & 0x80))
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }
  
  /* The partition must be a PC slice.  */
  if ((current_partition >> 16) == 0xFF
      || (current_partition & 0xFFFF) != 0xFFFF)
    {
      errnum = ERR_BAD_ARGUMENT;
      return 1;
    }

  /* Get the new partition type.  */
  arg = skip_to (0, arg);
  if (! safe_parse_maxint (&arg, &new_type))
    return 1;

  /* The partition type is unsigned char.  */
  if (new_type > 0xFF)