예제 #1
0
grub_err_t
grub_multiboot_load (grub_file_t file)
{
  char *buffer;
  grub_ssize_t len;
  struct multiboot_header *header;
  grub_err_t err;

  buffer = grub_malloc (MULTIBOOT_SEARCH);
  if (!buffer)
    return grub_errno;

  len = grub_file_read (file, buffer, MULTIBOOT_SEARCH);
  if (len < 32)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_OS, "file too small");
    }

  /* Look for the multiboot header in the buffer.  The header should
     be at least 12 bytes and aligned on a 4-byte boundary.  */
  for (header = (struct multiboot_header *) buffer;
       ((char *) header <= buffer + len - 12) || (header = 0);
       header = (struct multiboot_header *) ((char *) header + MULTIBOOT_HEADER_ALIGN))
    {
      if (header->magic == MULTIBOOT_HEADER_MAGIC
	  && !(header->magic + header->flags + header->checksum))
	break;
    }

  if (header == 0)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_ARGUMENT, "no multiboot header found");
    }

  if (header->flags & UNSUPPORTED_FLAGS)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_UNKNOWN_OS,
			 "unsupported flag: 0x%x", header->flags);
    }

  if (header->flags & MULTIBOOT_AOUT_KLUDGE)
    {
      int offset = ((char *) header - buffer -
		    (header->header_addr - header->load_addr));
      int load_size = ((header->load_end_addr == 0) ? file->size - offset :
		       header->load_end_addr - header->load_addr);
      grub_size_t code_size;
      void *source;
      grub_relocator_chunk_t ch;

      if (header->bss_end_addr)
	code_size = (header->bss_end_addr - header->load_addr);
      else
	code_size = load_size;

      err = grub_relocator_alloc_chunk_addr (grub_multiboot_relocator, 
					     &ch, header->load_addr,
					     code_size);
      if (err)
	{
	  grub_dprintf ("multiboot_loader", "Error loading aout kludge\n");
	  grub_free (buffer);
	  return err;
	}
      source = get_virtual_current_address (ch);

      if ((grub_file_seek (file, offset)) == (grub_off_t) -1)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      grub_file_read (file, source, load_size);
      if (grub_errno)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if (header->bss_end_addr)
	grub_memset ((grub_uint8_t *) source + load_size, 0,
		     header->bss_end_addr - header->load_addr - load_size);

      grub_multiboot_payload_eip = header->entry_addr;
    }
  else
    {
      err = grub_multiboot_load_elf (file, buffer);
      if (err)
	{
	  grub_free (buffer);
	  return err;
	}
    }

  if (header->flags & MULTIBOOT_VIDEO_MODE)
    {
      switch (header->mode_type)
	{
	case 1:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    0, 0, 0, 0);
	  break;
	case 0:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    header->width, header->height,
					    header->depth, 0);
	  break;
	default:
	  err = grub_error (GRUB_ERR_BAD_OS, 
			    "unsupported graphical mode type %d",
			    header->mode_type);
	  break;
	}
    }
  else
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
				      GRUB_MULTIBOOT_CONSOLE_EGA_TEXT,
				      0, 0, 0, 0);
  return err;
}
예제 #2
0
grub_err_t
grub_multiboot_load (grub_file_t file)
{
  char *buffer;
  grub_ssize_t len;
  struct multiboot_header *header;
  grub_err_t err;

  buffer = grub_malloc (MULTIBOOT_SEARCH);
  if (!buffer)
    return grub_errno;

  len = grub_file_read (file, buffer, MULTIBOOT_SEARCH);
  if (len < 32)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_OS, "file too small");
    }

  /* Look for the multiboot header in the buffer.  The header should
     be at least 12 bytes and aligned on a 4-byte boundary.  */
  for (header = (struct multiboot_header *) buffer;
       ((char *) header <= buffer + len - 12) || (header = 0);
       header = (struct multiboot_header *) ((char *) header + MULTIBOOT_HEADER_ALIGN))
    {
      if (header->magic == MULTIBOOT_HEADER_MAGIC
	  && !(header->magic + header->flags + header->checksum))
	break;
    }

  if (header == 0)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_ARGUMENT, "no multiboot header found");
    }

  if (header->flags & UNSUPPORTED_FLAGS)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_UNKNOWN_OS,
			 "unsupported flag: 0x%x", header->flags);
    }

  if (header->flags & MULTIBOOT_AOUT_KLUDGE)
    {
      int offset = ((char *) header - buffer -
		    (header->header_addr - header->load_addr));
      int load_size = ((header->load_end_addr == 0) ? file->size - offset :
		       header->load_end_addr - header->load_addr);
      grub_size_t code_size;

      if (header->bss_end_addr)
	code_size = (header->bss_end_addr - header->load_addr);
      else
	code_size = load_size;
      grub_multiboot_payload_dest = header->load_addr;

      grub_multiboot_pure_size += code_size;

      /* Allocate a bit more to avoid relocations in most cases.  */
      grub_multiboot_alloc_mbi = grub_multiboot_get_mbi_size () + 65536;
      grub_multiboot_payload_orig
	= grub_relocator32_alloc (grub_multiboot_pure_size + grub_multiboot_alloc_mbi);

      if (! grub_multiboot_payload_orig)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if ((grub_file_seek (file, offset)) == (grub_off_t) -1)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      grub_file_read (file, (void *) grub_multiboot_payload_orig, load_size);
      if (grub_errno)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if (header->bss_end_addr)
	grub_memset ((void *) (grub_multiboot_payload_orig + load_size), 0,
		     header->bss_end_addr - header->load_addr - load_size);

      grub_multiboot_payload_eip = header->entry_addr;

    }
  else
    {
      err = grub_multiboot_load_elf (file, buffer);
      if (err)
	{
	  grub_free (buffer);
	  return err;
	}
    }

  if (header->flags & MULTIBOOT_VIDEO_MODE)
    {
      switch (header->mode_type)
	{
	case 1:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    0, 0, 0, 0);
	  break;
	case 0:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    header->width, header->height,
					    header->depth, 0);
	  break;
	default:
	  err = grub_error (GRUB_ERR_BAD_OS, 
			    "unsupported graphical mode type %d",
			    header->mode_type);
	  break;
	}
    }
  else
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
				      GRUB_MULTIBOOT_CONSOLE_EGA_TEXT,
				      0, 0, 0, 0);
  return err;
}
예제 #3
0
grub_err_t
grub_multiboot_load (grub_file_t file, const char *filename)
{
  char *buffer;
  grub_ssize_t len;
  struct multiboot_header *header;
  grub_err_t err;

  buffer = grub_malloc (MULTIBOOT_SEARCH);
  if (!buffer)
    return grub_errno;

  len = grub_file_read (file, buffer, MULTIBOOT_SEARCH);
  if (len < 32)
    {
      grub_free (buffer);
      if (!grub_errno)
	grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
		    filename);
      return grub_errno;
    }

  header = find_header (buffer, len);

  if (header == 0)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_ARGUMENT, "no multiboot header found");
    }

  if (header->flags & UNSUPPORTED_FLAGS)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_UNKNOWN_OS,
			 "unsupported flag: 0x%x", header->flags);
    }

  err = load_kernel (file, filename, buffer, header);
  if (err)
    {
      grub_free (buffer);
      return err;
    }

  if (header->flags & MULTIBOOT_VIDEO_MODE)
    {
      switch (header->mode_type)
	{
	case 1:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    0, 0, 0, 0);
	  break;
	case 0:
	  err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    GRUB_MULTIBOOT_CONSOLE_EGA_TEXT
					    | GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
					    header->width, header->height,
					    header->depth, 0);
	  break;
	default:
	  err = grub_error (GRUB_ERR_BAD_OS, 
			    "unsupported graphical mode type %d",
			    header->mode_type);
	  break;
	}
    }
  else
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT, 
				      GRUB_MULTIBOOT_CONSOLE_EGA_TEXT,
				      0, 0, 0, 0);
  return err;
}
예제 #4
0
파일: multiboot_mbi2.c 프로젝트: cuidi/grub
grub_err_t
grub_multiboot_load (grub_file_t file, const char *filename)
{
  grub_properly_aligned_t *buffer;
  grub_ssize_t len;
  struct multiboot_header *header;
  grub_err_t err;
  struct multiboot_header_tag *tag;
  struct multiboot_header_tag_address *addr_tag = NULL;
  int entry_specified = 0;
  grub_addr_t entry = 0;
  grub_uint32_t console_required = 0;
  struct multiboot_header_tag_framebuffer *fbtag = NULL;
  int accepted_consoles = GRUB_MULTIBOOT_CONSOLE_EGA_TEXT;

  buffer = grub_malloc (MULTIBOOT_SEARCH);
  if (!buffer)
    return grub_errno;

  len = grub_file_read (file, buffer, MULTIBOOT_SEARCH);
  if (len < 32)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), filename);
    }

  COMPILE_TIME_ASSERT (MULTIBOOT_HEADER_ALIGN % 4 == 0);

  grub_tpm_measure ((unsigned char *)buffer, len, GRUB_BINARY_PCR, "grub_multiboot", filename);

  header = find_header (buffer, len);

  if (header == 0)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_ARGUMENT, "no multiboot header found");
    }

  COMPILE_TIME_ASSERT (MULTIBOOT_TAG_ALIGN % 4 == 0);

  keep_bs = 0;

  for (tag = (struct multiboot_header_tag *) (header + 1);
       tag->type != MULTIBOOT_TAG_TYPE_END;
       tag = (struct multiboot_header_tag *) ((grub_uint32_t *) tag + ALIGN_UP (tag->size, MULTIBOOT_TAG_ALIGN) / 4))
    switch (tag->type)
      {
      case MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST:
	{
	  unsigned i;
	  struct multiboot_header_tag_information_request *request_tag
	    = (struct multiboot_header_tag_information_request *) tag;
	  if (request_tag->flags & MULTIBOOT_HEADER_TAG_OPTIONAL)
	    break;
	  for (i = 0; i < (request_tag->size - sizeof (*request_tag))
		 / sizeof (request_tag->requests[0]); i++)
	    switch (request_tag->requests[i])
	      {
	      case MULTIBOOT_TAG_TYPE_END:
	      case MULTIBOOT_TAG_TYPE_CMDLINE:
	      case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
	      case MULTIBOOT_TAG_TYPE_MODULE:
	      case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
	      case MULTIBOOT_TAG_TYPE_BOOTDEV:
	      case MULTIBOOT_TAG_TYPE_MMAP:
	      case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
	      case MULTIBOOT_TAG_TYPE_VBE:
	      case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
	      case MULTIBOOT_TAG_TYPE_APM:
	      case MULTIBOOT_TAG_TYPE_EFI32:
	      case MULTIBOOT_TAG_TYPE_EFI64:
	      case MULTIBOOT_TAG_TYPE_ACPI_OLD:
	      case MULTIBOOT_TAG_TYPE_ACPI_NEW:
	      case MULTIBOOT_TAG_TYPE_NETWORK:
	      case MULTIBOOT_TAG_TYPE_EFI_MMAP:
	      case MULTIBOOT_TAG_TYPE_EFI_BS:
		break;

	      default:
		grub_free (buffer);
		return grub_error (GRUB_ERR_UNKNOWN_OS,
				   "unsupported information tag: 0x%x",
				   request_tag->requests[i]);
	      }
	  break;
	}
	       
      case MULTIBOOT_HEADER_TAG_ADDRESS:
	addr_tag = (struct multiboot_header_tag_address *) tag;
	break;

      case MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS:
	entry_specified = 1;
	entry = ((struct multiboot_header_tag_entry_address *) tag)->entry_addr;
	break;

      case MULTIBOOT_HEADER_TAG_CONSOLE_FLAGS:
	if (!(((struct multiboot_header_tag_console_flags *) tag)->console_flags
	    & MULTIBOOT_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED))
	  accepted_consoles &= ~GRUB_MULTIBOOT_CONSOLE_EGA_TEXT;
	if (((struct multiboot_header_tag_console_flags *) tag)->console_flags
	    & MULTIBOOT_CONSOLE_FLAGS_CONSOLE_REQUIRED)
	  console_required = 1;
	break;

      case MULTIBOOT_HEADER_TAG_FRAMEBUFFER:
	fbtag = (struct multiboot_header_tag_framebuffer *) tag;
	accepted_consoles |= GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER;
	break;

	/* GRUB always page-aligns modules.  */
      case MULTIBOOT_HEADER_TAG_MODULE_ALIGN:
	break;

      case MULTIBOOT_HEADER_TAG_EFI_BS:
	keep_bs = 1;
	break;

      default:
	if (! (tag->flags & MULTIBOOT_HEADER_TAG_OPTIONAL))
	  {
	    grub_free (buffer);
	    return grub_error (GRUB_ERR_UNKNOWN_OS,
			       "unsupported tag: 0x%x", tag->type);
	  }
	break;
      }

  if (addr_tag && !entry_specified)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_UNKNOWN_OS,
			 "load address tag without entry address tag");
    }
 
  if (addr_tag)
    {
      grub_uint64_t load_addr = (addr_tag->load_addr + 1)
	? addr_tag->load_addr : (addr_tag->header_addr
				 - ((char *) header - (char *) buffer));
      int offset = ((char *) header - (char *) buffer -
	   (addr_tag->header_addr - load_addr));
      int load_size = ((addr_tag->load_end_addr == 0) ? file->size - offset :
		       addr_tag->load_end_addr - addr_tag->load_addr);
      grub_size_t code_size;
      void *source;
      grub_relocator_chunk_t ch;

      if (addr_tag->bss_end_addr)
	code_size = (addr_tag->bss_end_addr - load_addr);
      else
	code_size = load_size;

      err = grub_relocator_alloc_chunk_addr (grub_multiboot_relocator, 
					     &ch, load_addr,
					     code_size);
      if (err)
	{
	  grub_dprintf ("multiboot_loader", "Error loading aout kludge\n");
	  grub_free (buffer);
	  return err;
	}
      source = get_virtual_current_address (ch);

      if ((grub_file_seek (file, offset)) == (grub_off_t) -1)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      grub_file_read (file, source, load_size);
      if (grub_errno)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if (addr_tag->bss_end_addr)
	grub_memset ((grub_uint8_t *) source + load_size, 0,
		     addr_tag->bss_end_addr - load_addr - load_size);
    }
  else
    {
      err = grub_multiboot_load_elf (file, filename, buffer);
      if (err)
	{
	  grub_free (buffer);
	  return err;
	}
    }

  if (entry_specified)
    grub_multiboot_payload_eip = entry;

  if (fbtag)
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
				      accepted_consoles,
				      fbtag->width, fbtag->height,
				      fbtag->depth, console_required);
  else
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT,
				      accepted_consoles,
				      0, 0, 0, console_required);
  return err;
}
예제 #5
0
grub_err_t
grub_multiboot_load (grub_file_t file)
{
  char *buffer;
  grub_ssize_t len;
  struct multiboot_header *header;
  grub_err_t err;
  struct multiboot_header_tag *tag;
  struct multiboot_header_tag_address *addr_tag = NULL;
  int entry_specified = 0;
  grub_addr_t entry = 0;
  grub_uint32_t console_required = 0;
  struct multiboot_header_tag_framebuffer *fbtag = NULL;
  int accepted_consoles = GRUB_MULTIBOOT_CONSOLE_EGA_TEXT;

  buffer = grub_malloc (MULTIBOOT_SEARCH);
  if (!buffer)
    return grub_errno;

  len = grub_file_read (file, buffer, MULTIBOOT_SEARCH);
  if (len < 32)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_OS, "file too small");
    }

  /* Look for the multiboot header in the buffer.  The header should
     be at least 12 bytes and aligned on a 4-byte boundary.  */
  for (header = (struct multiboot_header *) buffer;
       ((char *) header <= buffer + len - 12) || (header = 0);
       header = (struct multiboot_header *) ((char *) header + MULTIBOOT_HEADER_ALIGN))
    {
      if (header->magic == MULTIBOOT_HEADER_MAGIC
	  && !(header->magic + header->architecture
	       + header->header_length + header->checksum)
	  && header->architecture == MULTIBOOT_ARCHITECTURE_CURRENT)
	break;
    }

  if (header == 0)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_BAD_ARGUMENT, "no multiboot header found");
    }

  for (tag = (struct multiboot_header_tag *) (header + 1);
       tag->type != MULTIBOOT_TAG_TYPE_END;
       tag = (struct multiboot_header_tag *) ((char *) tag + tag->size))
    switch (tag->type)
      {
      case MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST:
	{
	  unsigned i;
	  struct multiboot_header_tag_information_request *request_tag
	    = (struct multiboot_header_tag_information_request *) tag;
	  if (request_tag->flags & MULTIBOOT_HEADER_TAG_OPTIONAL)
	    break;
	  for (i = 0; i < (request_tag->size - sizeof (request_tag))
		 / sizeof (request_tag->requests[0]); i++)
	    switch (request_tag->requests[i])
	      {
	      case MULTIBOOT_TAG_TYPE_END:
	      case MULTIBOOT_TAG_TYPE_CMDLINE:
	      case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
	      case MULTIBOOT_TAG_TYPE_MODULE:
	      case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
	      case MULTIBOOT_TAG_TYPE_BOOTDEV:
	      case MULTIBOOT_TAG_TYPE_MMAP:
	      case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
		break;

	      case MULTIBOOT_TAG_TYPE_VBE:
	      case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
	      case MULTIBOOT_TAG_TYPE_APM:
	      default:
		grub_free (buffer);
		return grub_error (GRUB_ERR_UNKNOWN_OS,
				   "unsupported information tag: 0x%x",
				   request_tag->requests[i]);
	      }
	  break;
	}
	       
      case MULTIBOOT_HEADER_TAG_ADDRESS:
	addr_tag = (struct multiboot_header_tag_address *) tag;
	break;

      case MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS:
	entry_specified = 1;
	entry = ((struct multiboot_header_tag_entry_address *) tag)->entry_addr;
	break;

      case MULTIBOOT_HEADER_TAG_CONSOLE_FLAGS:
	if (!(((struct multiboot_header_tag_console_flags *) tag)->console_flags
	    & MULTIBOOT_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED))
	  accepted_consoles &= ~GRUB_MULTIBOOT_CONSOLE_EGA_TEXT;
	if (((struct multiboot_header_tag_console_flags *) tag)->console_flags
	    & MULTIBOOT_CONSOLE_FLAGS_CONSOLE_REQUIRED)
	  console_required = 1;
	break;

      case MULTIBOOT_HEADER_TAG_FRAMEBUFFER:
	fbtag = (struct multiboot_header_tag_framebuffer *) tag;
	accepted_consoles |= GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER;
	break;

	/* GRUB always page-aligns modules.  */
      case MULTIBOOT_HEADER_TAG_MODULE_ALIGN:
	break;

      default:
	if (! (tag->flags & MULTIBOOT_HEADER_TAG_OPTIONAL))
	  {
	    grub_free (buffer);
	    return grub_error (GRUB_ERR_UNKNOWN_OS,
			       "unsupported tag: 0x%x", tag->type);
	  }
	break;
      }

  if (addr_tag && !entry_specified)
    {
      grub_free (buffer);
      return grub_error (GRUB_ERR_UNKNOWN_OS,
			 "load address tag without entry address tag");
    }
 
  if (addr_tag)
    {
      int offset = ((char *) header - buffer -
		    (addr_tag->header_addr - addr_tag->load_addr));
      int load_size = ((addr_tag->load_end_addr == 0) ? file->size - offset :
		       addr_tag->load_end_addr - addr_tag->load_addr);
      grub_size_t code_size;

      if (addr_tag->bss_end_addr)
	code_size = (addr_tag->bss_end_addr - addr_tag->load_addr);
      else
	code_size = load_size;
      grub_multiboot_payload_dest = addr_tag->load_addr;

      grub_multiboot_pure_size += code_size;

      /* Allocate a bit more to avoid relocations in most cases.  */
      grub_multiboot_alloc_mbi = grub_multiboot_get_mbi_size () + 65536;
      grub_multiboot_payload_orig
	= grub_relocator32_alloc (grub_multiboot_pure_size + grub_multiboot_alloc_mbi);

      if (! grub_multiboot_payload_orig)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if ((grub_file_seek (file, offset)) == (grub_off_t) -1)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      grub_file_read (file, (void *) grub_multiboot_payload_orig, load_size);
      if (grub_errno)
	{
	  grub_free (buffer);
	  return grub_errno;
	}

      if (addr_tag->bss_end_addr)
	grub_memset ((void *) (grub_multiboot_payload_orig + load_size), 0,
		     addr_tag->bss_end_addr - addr_tag->load_addr - load_size);
    }
  else
    {
      err = grub_multiboot_load_elf (file, buffer);
      if (err)
	{
	  grub_free (buffer);
	  return err;
	}
    }

  if (entry_specified)
    grub_multiboot_payload_eip = entry;

  if (fbtag)
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_FRAMEBUFFER,
				      accepted_consoles,
				      fbtag->width, fbtag->height,
				      fbtag->depth, console_required);
  else
    err = grub_multiboot_set_console (GRUB_MULTIBOOT_CONSOLE_EGA_TEXT,
				      accepted_consoles,
				      0, 0, 0, console_required);
  return err;
}