builtins.c

grub4dos-0.4.4-2008- 08-src.zip

	{
		errnum = ERR_INVALID_LOAD_SEGMENT;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--load-offset=", 14) == 0)
      {
	p = arg + 14;
	if (! safe_parse_maxint (&p, &chainloader_load_offset))
		goto failure;
	if (chainloader_load_offset < 0 || chainloader_load_offset > 0xffff)
	{
		errnum = ERR_INVALID_LOAD_OFFSET;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--load-length=", 14) == 0)
      {
	p = arg + 14;
	if (! safe_parse_maxint (&p, &chainloader_load_length))
		goto failure;
	if (chainloader_load_length < 512 || chainloader_load_length > 0xa0000)
	{
		errnum = ERR_INVALID_LOAD_LENGTH;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--skip-length=", 14) == 0)
      {
	p = arg + 14;
	if (! safe_parse_maxint (&p, &chainloader_skip_length))
		goto failure;
	if (chainloader_skip_length < 0)
	{
		errnum = ERR_INVALID_SKIP_LENGTH;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--boot-cs=", 10) == 0)
      {
	p = arg + 10;
	if (! safe_parse_maxint (&p, &chainloader_boot_CS))
		goto failure;
	if (chainloader_boot_CS < 0 || chainloader_boot_CS > 0xffff)
	{
		errnum = ERR_INVALID_BOOT_CS;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--boot-ip=", 10) == 0)
      {
	p = arg + 10;
	if (! safe_parse_maxint (&p, &chainloader_boot_IP))
		goto failure;
	if (chainloader_boot_IP < 0 || chainloader_boot_IP > 0xffff)
	{
		errnum = ERR_INVALID_BOOT_IP;
		goto failure;
	}
      }
    else if (grub_memcmp (arg, "--ebx=", 6) == 0)
      {
	p = arg + 6;
	if (! safe_parse_maxint (&p, (int *)(void *)&chainloader_ebx))
		goto failure;
	chainloader_ebx_set = 1;
      }
    else if (grub_memcmp (arg, "--edx=", 6) == 0)
      {
	p = arg + 6;
	if (! safe_parse_maxint (&p, (int *)(void *)&chainloader_edx))
		goto failure;
	chainloader_edx_set = 1;
      }
    else if (grub_memcmp (arg, "--sdi", 5) == 0)
      {
	is_sdi = 1;
      }
    else if (grub_memcmp (arg, "--raw", 5) == 0)
      {
	is_raw = 1;
      }
    else if (grub_memcmp (arg, "--disable-a20", 13) == 0)
      {
	chainloader_disable_A20 = 1;
      }
    else
	break;
    arg = skip_to (0, arg);
  }
  
  if (grub_strlen(saved_dir) + grub_strlen(arg) + 20 >= sizeof(chainloader_file))
    {
	errnum = ERR_WONT_FIT;
	goto failure;
    }

  if (*arg == '/')
  {
    if (saved_partition != 0xFFFFFF)
    {
      if ((saved_partition & 0xFF00) == 0xFF00)
	grub_sprintf (chainloader_file, "(%d,%d)%s%s", saved_drive, (char)(saved_partition>>16), saved_dir, arg);
      else
	if ((saved_partition & 0xFF0000) == 0xFF0000)
	  grub_sprintf (chainloader_file, "(%d,%c)%s%s", saved_drive, (char)(saved_partition>>8) + 'a', saved_dir, arg);
	else
	  grub_sprintf (chainloader_file, "(%d,%d,%c)%s%s", saved_drive,  (char)(saved_partition>>16), (char)(saved_partition>>8) + 'a', saved_dir, arg);
    }
    else
      grub_sprintf (chainloader_file, "(%d)%s%s", saved_drive, saved_dir, arg);
  }
  else if (*arg == '(' && arg[1] == ')')
  {
    if (saved_partition != 0xFFFFFF)
    {
      if ((saved_partition & 0xFF00) == 0xFF00)
	grub_sprintf (chainloader_file, "(%d,%d)%s", saved_drive, (char)(saved_partition>>16), arg + 2);
      else
	if ((saved_partition & 0xFF0000) == 0xFF0000)
	  grub_sprintf (chainloader_file, "(%d,%c)%s", saved_drive, (char)(saved_partition>>8) + 'a', arg + 2);
	else
	  grub_sprintf (chainloader_file, "(%d,%d,%c)%s", saved_drive, (char)(saved_partition>>16), (char)(saved_partition>>8) + 'a', arg + 2);
    }
    else
      grub_sprintf (chainloader_file, "(%d)%s", saved_drive, arg + 2);
  } else if (*arg != '(')
  {
    if (saved_partition != 0xFFFFFF)
    {
      if ((saved_partition & 0xFF00) == 0xFF00)
	grub_sprintf (chainloader_file, "(%d,%d)%s", saved_drive, (char)(saved_partition>>16), arg);
      else
	if ((saved_partition & 0xFF0000) == 0xFF0000)
	  grub_sprintf (chainloader_file, "(%d,%c)%s", saved_drive, (char)(saved_partition>>8) + 'a', arg);
	else
	  grub_sprintf (chainloader_file, "(%d,%d,%c)%s", saved_drive, (char)(saved_partition>>16), (char)(saved_partition>>8) + 'a', arg);
    }
    else
      grub_sprintf (chainloader_file, "(%d)%s", saved_drive, arg);
  }
  else
	grub_memmove (chainloader_file, arg, 255);
  chainloader_file[255]=0;

  errnum = ERR_NONE;
  
  if ((is_sdi) || (is_raw))
    return 1;

//  if (debug > 0)
//	printf ("Debug: chainloader_func: set_device(%s) ...", arg);

  /* Get the drive number.  */
  filename = set_device (arg);

//  if (debug > 0)
//	/* wipe out debug message. */
//	printf ("\r                                                                             \r");

  if (errnum) {
	/* No device specified. Default to the root device. */
	current_drive = saved_drive;
	//current_partition = saved_partition;
	filename = arg;
	errnum = 0;
  }
  
  if (filename == 0)
	filename = arg;

#ifndef GRUB_UTIL
  /* check bootable cdrom */
  if (*filename == 0 || *filename == ' ' || *filename == '\t')
  {
	//check_bootable_cdrom (current_drive);
	//unsigned long i;
	unsigned long tmp;
	unsigned short tmp1;
	unsigned short tmp2;
//	struct geometry tmp_geom;
	
	tmp = current_drive;
	/* check bootable type of drive (tmp) */

//grub_printf ("get_diskinfo(0x%X)\n", tmp);
      
	/* Get the geometry. This ensures that the drive is present.  */
	if (get_diskinfo (tmp, &tmp_geom))
	{
		errnum = ERR_NO_DISK;
		goto failure;
	}

//grub_printf ("get_diskinfo ok.\n");

	/* open the drive */
	
	grub_sprintf ((char *)SCRATCHADDR, "(0x%X)+0x%X", tmp, tmp_geom.total_sectors);

//grub_printf ("grub_open(%s)\n", SCRATCHADDR);

	if (! grub_open ((char *)SCRATCHADDR))
		goto failure;
	
//grub_printf ("filemax=%X\n", filemax);

	/****************************************/
	/* read the EL Torito Volume Descriptor */
	/****************************************/

	//filemax = 0x12 * 0x800;
	filepos = 0x11 * 0x800;

	if (grub_read ((char *)SCRATCHADDR, 512) != 512)
		goto failure_exec_format;

//grub_printf ("grub_read ok.\n");

	/* check the EL Torito Volume Descriptor */

	if (memcmp ((char *)SCRATCHADDR, "\0CD001\1EL TORITO SPECIFICATION\0", 31))
		goto failure_exec_format;
	
	/* get absolut start sector number for boot catalog */
	tmp = *(unsigned long *)((char *)SCRATCHADDR + 0x47);

	/********************************************/
	/* read the first 512 bytes of Boot Catalog */
	/********************************************/

	//filemax = (tmp + 1) * 0x800;
	filepos = tmp * 0x800;
	
	if (grub_read ((char *)SCRATCHADDR, 512) != 512)
		goto failure_exec_format;

	/*******************************/
	/* check the Validation Entry  */
	/*******************************/

	tmp1 = 0;
	for (i = 0; i < 16; i++)
	{
		tmp = *(((unsigned short *)(char *)SCRATCHADDR) + i);
		tmp1 += tmp;
		if ((i == 0 && tmp != 1) || (i == 15 && tmp != 0xAA55))
			break;
	}

	if (tmp1 || i < 16)
		goto failure_exec_format;

	/* Boot Record Volume Descriptor format
	 *
	 * Offset     Type	Description
	 * ------     ----	----------------------------------------------
	 *   0	      Byte	Boot Record Indicator, must be 0
	 *
	 *  1-5	   Characters	ISO-9660 Identifier, must be "CD001"
	 *
	 *   6	      Byte	Version of this descriptor, must be 1
	 *
	 *  7-26   Characters	Boot System Identifier, must be
	 *			"EL TORITO SPECIFICATION" padded with 0's.
	 *
	 * 27-46   Characters	Unused, must be 0.
	 *
	 * 47-4A     Dword	LBA of the first sector of Boot Catalog.
	 *
	 * 4B-7FF  Characters	Unused, must be 0.
	 *
	 */

	/* Validation Entry format
	 *
	 * Offset     Type	Description
	 * ------     ----	----------------------------------------------
	 *   0	      Byte	Header ID, must be 01
	 *
	 *   1	      Byte	Platform ID
	 *				0 = 80x86
	 *				1 = Power PC
	 *				2 = Mac
	 *
	 *  2-3	      Word	Reserved, must be 0
	 *
	 *  4-1B   Characters	ID string. This is intended to identify the
	 *			manufacturer/developer of the CD-ROM.
	 *
	 * 1C-1D      Word	Checksum Word. This sum of all the words in
	 *			this record should be 0.
	 *
	 *  1E        Byte	Key byte, must be 55. This value is included
	 *			in the checksum.
	 *
	 *  1F        Byte	Key byte, must be AA. This value is included
	 *			in the checksum.
	 *
	 */

	/* Initial/Default Entry format
	 *
	 * Offset	Type	Description
	 * ------	----	----------------------------------------------
	 *	0	Byte	Boot Indicator. 88=Bootable, 00=Not Bootable
	 *	
	 *	1	Byte	Boot media type.
	 *			0 = No Emulation
	 *			1 = 1.2 meg diskette
	 *			2 = 1.44 meg diskette
	 *			3 = 2.88 meg diskette
	 *			4 = Hard Disk(drive 80)
	 *
	 *	2	Word	Load Segment. 0 for 7C0
	 *
	 *	4	Byte	System Type.
	 *
	 *	5	Byte	Unused, must be 0.
	 *
	 *	6	Word	Sector Count. This is the number of virtual/
	 *			emulated sectors the system will store at Load
	 *			Segment during the initial boot procedure.
	 *
	 *	8	DWord	Load RBA. This is the start address of the
	 *			virtual disk. CD's use Relative/Logical block
	 *			addressing.
	 *
	 *	C	Bytes	Unused, must be 0's.
	 *
	 */

	/* Specification Packet format
	 *
	 * Offset	Type	Description
	 * ------	----	----------------------------------------------
	 *	0	Byte	Packet Size, currently 13
	 *
	 *	1	Byte	Boot media type. This specifies what media the
	 *			boot image is intended to emulate in bits 0-3.
	 *			Bits 6-7 are specific to the type of system.
	 *
	 *			Bits 0-3 count as follows:
	 *			
	 *				0:	No Emulation
	 *				1:	1.2  meg diskette
	 *				2:	1.44 meg diskette
	 *				3:	2.88 meg diskette
	 *				4:	Hard Disk (drive C)
	 *
	 *				5-F:	Reserved, invalid at this time
	 *
	 *			bits 4-5 - Reserved, must be 0
	 *			bit 6 - Image contains an ATAPI driver,
	 *				bytes 8 & 9 refer to IDE interface
	 *			bit 7 - Image contains SCSI drivers,
	 *				bytes 8 & 9 refer to SCSI interface
	 *
	 *	2	Byte	Drive Number. This is the drive number on
	 *			which emulation is being initiated or
	 *			terminated. This must be 0 for a floppy image,
	 *			80 for a bootable hard disk, and 81-FF for a
	 *			"non-bootable" or "no emulation" drive.
	 *
	 *	3	Byte	Controller Index. This specifies the controller
	 *			number of the specified CD drive.
	 *
	 *	4-7	Dword	Logical Block Address for the disk image to be
	 *			emulated.
	 *
	 *	8-9	Word	Device Specification. For SCSI controllers byte
	 *			8 is the LUN and PUN of the CD Drive, byte 9 is
	 *			the Bus number. For IDE controllers the low
	 *			order bit of byte 8 specifies master/slave
	 *			device, 0 = master.
	 *
	 *	A-B	Word	User Buffer Segment. If this field is non-zero
	 *			it specifies the segment of a user supplied 3k
	 *			buffer for caching CD reads. This buffer will
	 *			begin at Segment:0.
	 *
	 *	C-D	Word	Load Segment. This is the load address for the
	 *			initial boot image. If this value is 0, the
	 *			system will use the traditional segment of 7C0.
	 *			If this value is non-zero the system will use
	 *			the specified address. This field is only valid
	 *			for function 4C.
	 *
	 *	E-F	Word	Sector Count. This is the number of virtual
	 *			sectors the system will store at Load Segment
	 *			during the initial boot procedure. This field
	 *			is only valid for function 4C.
	 *
	 *	10	Byte	Bits 0-7 of the cylinder count. This should
	 *			match the value returned in CH when INT 13
	 *			function 08 is invoked.
	 *
	 *	11	Byte	This is the value returned in the CL register
	 *			when INT 13 function 08 is invoked. Bits 0-5
	 *			are the sector count. Bits 6 and 7 are the high
	 *			order 2 bits of the cylinder count.
	 *
	 *	12	Byte	This is the head count, it should match the
	 *			value in DH when INT 13 Function 08 is invoked.
	 *
	 */

	/***********************************/
	/* check the Initial/Default Entry */
	/***********************************/

	/* XXX: assume Initial/Default Entry is always at offset 0x20 */

	tmp = *(unsigned char *)(SCRATCHADDR + 0x20);	/* Boot Indicator. 88=Bootable, 00=Not Bootable */

	if (tmp != 0x88)
		goto failure_exec_format;

	tmp = *((unsigned char *)SCRATCHADDR + 0x25);	/* Unused byte, must be 0. */

	if (tmp)
		goto failure_exec_format;
	
	tmp2 = *((unsigned short *)((unsigned char *)SCRATCHADDR + 0x22));	/* Load Segment */

	if (debug > 0)
		printf ("\nLoad segment: 0x%X\t", tmp2);

	if (tmp2 == 0)
		tmp2 = 0x7C0;

//	*(unsigned short *)&(chainloader_file[0x0C]) = tmp2;	/* 0C-0D: load segment */
	
	tmp = *((unsigned char *)SCRATCHADDR + 0x24);	/* System Type */

	if (debug > 0)
		printf ("System Type: 0x%X\t", tmp);
	
	i = *((unsigned short *)((unsigned char *)SCRATCHADDR + 0x26));	/* Sector Count */

	if (debug > 0)
		printf ("Sector Count: 0x%X\n", i);

//	*(unsigned short *)&(chainloader_file[0x0E]) = i;	/* 0E-0F: sector count in 512-byte sectors */
	
	tmp = *((unsigned long *)((unsigned char *)SCRATCHADDR + 0x28));	/* Load RBA */

	if (debug > 0)
		printf ("Load RBA: 0x%X\t", tmp);

//	*(unsigned long *)&(chainloader_file[4]) = tmp;		/* 04-07: LBA of the image to be emulated */
	
	tmp1 = *((unsigned char *)SCRATCHADDR + 0x21);	/* Boot media type */

	if (tmp1 > 4)
		goto failure_exec_format;

	if (debug > 0)
		printf ("Boot Type: %s\n",
			tmp1 == 0 ? "0 = No Emulation" :
			tmp1 == 1 ? "1 = 1.2M floppy"  :