grub-setup.c

最新的grub2源代码

/* grub-setup.c - make GRUB usable */
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004,2005 Free Software Foundation, Inc.
 *
 *  GRUB 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; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GRUB; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <config.h>
#include <grub/types.h>
#include <grub/util/misc.h>
#include <grub/device.h>
#include <grub/disk.h>
#include <grub/file.h>
#include <grub/fs.h>
#include <grub/partition.h>
#include <grub/pc_partition.h>
#include <grub/env.h>
#include <grub/machine/util/biosdisk.h>
#include <grub/machine/boot.h>
#include <grub/machine/kernel.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <grub/util/getroot.h>

#define _GNU_SOURCE	1
#include <getopt.h>

#define DEFAULT_BOOT_FILE	"boot.img"
#define DEFAULT_CORE_FILE	"core.img"

#ifdef __NetBSD__
/* NetBSD uses /boot for its boot block.  */
# define DEFAULT_DIRECTORY	"/grub"
#else
# define DEFAULT_DIRECTORY	"/boot/grub"
#endif

#define DEFAULT_DEVICE_MAP	DEFAULT_DIRECTORY "/device.map"

/* This is the blocklist used in the diskboot image.  */
struct boot_blocklist
{
  grub_uint32_t start;
  grub_uint16_t len;
  grub_uint16_t segment;
} __attribute__ ((packed));

void
grub_putchar (int c)
{
  putchar (c);
}

void
grub_refresh (void)
{
}

static void
setup (const char *prefix, const char *dir,
       const char *boot_file, const char *core_file,
       const char *root, const char *dest)
{
  char *boot_path, *core_path;
  char *boot_img, *core_img;
  size_t boot_size, core_size;
  grub_uint16_t core_sectors;
  grub_device_t root_dev, dest_dev;
  grub_uint8_t *boot_drive;
  grub_uint32_t *kernel_sector;
  grub_uint16_t *boot_drive_check;
  struct boot_blocklist *first_block, *block;
  grub_int32_t *install_dos_part, *install_bsd_part;
  char *install_prefix;
  char *tmp_img;
  int i;
  unsigned long first_sector;
  grub_uint16_t current_segment
    = GRUB_BOOT_MACHINE_KERNEL_SEG + (GRUB_DISK_SECTOR_SIZE >> 4);
  grub_uint16_t last_length = GRUB_DISK_SECTOR_SIZE;
  grub_file_t file;
  FILE *fp;
  unsigned long first_start = ~0UL;
  
  auto void save_first_sector (unsigned long sector, unsigned offset,
			       unsigned length);
  auto void save_blocklists (unsigned long sector, unsigned offset,
			     unsigned length);

  auto int find_first_partition_start (grub_disk_t disk,
				       const grub_partition_t p);
  
  int find_first_partition_start (grub_disk_t disk __attribute__ ((unused)),
				  const grub_partition_t p)
    {
      struct grub_pc_partition *pcdata = p->data;

      if (! grub_pc_partition_is_empty (pcdata->dos_type)
	  && ! grub_pc_partition_is_bsd (pcdata->dos_type)
	  && first_start > p->start)
	first_start = p->start;
      
      return 0;
    }
  
  void save_first_sector (unsigned long sector, unsigned offset,
			  unsigned length)
    {
      grub_util_info ("the fist sector is <%lu,%u,%u>",
		      sector, offset, length);
      
      if (offset != 0 || length != GRUB_DISK_SECTOR_SIZE)
	grub_util_error ("The first sector of the core file is not sector-aligned");

      first_sector = sector;
    }

  void save_blocklists (unsigned long sector, unsigned offset, unsigned length)
    {
      struct boot_blocklist *prev = block + 1;

      grub_util_info ("saving <%lu,%u,%u> with the segment 0x%x",
		      sector, offset, length, (unsigned) current_segment);
      
      if (offset != 0 || last_length != GRUB_DISK_SECTOR_SIZE)
	grub_util_error ("Non-sector-aligned data is found in the core file");

      if (block != first_block
	  && (grub_le_to_cpu32 (prev->start)
	      + grub_le_to_cpu16 (prev->len)) == sector)
	prev->len = grub_cpu_to_le16 (grub_le_to_cpu16 (prev->len) + 1);
      else
	{
	  block->start = grub_cpu_to_le32 (sector);
	  block->len = grub_cpu_to_le16 (1);
	  block->segment = grub_cpu_to_le16 (current_segment);

	  block--;
	  if (block->len)
	    grub_util_error ("The sectors of the core file are too fragmented");
	}
      
      last_length = length;
      current_segment += GRUB_DISK_SECTOR_SIZE >> 4;
    }
  
  /* Read the boot image by the OS service.  */
  boot_path = grub_util_get_path (dir, boot_file);
  boot_size = grub_util_get_image_size (boot_path);
  if (boot_size != GRUB_DISK_SECTOR_SIZE)
    grub_util_error ("The size of `%s' is not %d",
		     boot_path, GRUB_DISK_SECTOR_SIZE);
  boot_img = grub_util_read_image (boot_path);
  free (boot_path);

  /* Set the addresses of BOOT_DRIVE, KERNEL_SECTOR and BOOT_DRIVE_CHECK.  */
  boot_drive = (grub_uint8_t *) (boot_img + GRUB_BOOT_MACHINE_BOOT_DRIVE);
  kernel_sector = (grub_uint32_t *) (boot_img
				     + GRUB_BOOT_MACHINE_KERNEL_SECTOR);
  boot_drive_check = (grub_uint16_t *) (boot_img
					+ GRUB_BOOT_MACHINE_DRIVE_CHECK);
  
  core_path = grub_util_get_path (dir, core_file);
  core_size = grub_util_get_image_size (core_path);
  core_sectors = ((core_size + GRUB_DISK_SECTOR_SIZE - 1)
		  >> GRUB_DISK_SECTOR_BITS);
  if (core_size < GRUB_DISK_SECTOR_SIZE)
    grub_util_error ("The size of `%s' is too small", core_path);
  else if (core_size > 0xFFFF * GRUB_DISK_SECTOR_SIZE)
    grub_util_error ("The size of `%s' is too large", core_path);
  
  core_img = grub_util_read_image (core_path);
  free (core_path);

  /* Have FIRST_BLOCK to point to the first blocklist.  */
  first_block = (struct boot_blocklist *) (core_img
					   + GRUB_DISK_SECTOR_SIZE
					   - sizeof (*block));

  install_dos_part = (grub_int32_t *) (core_img + GRUB_DISK_SECTOR_SIZE
				       + GRUB_KERNEL_MACHINE_INSTALL_DOS_PART);
  install_bsd_part = (grub_int32_t *) (core_img + GRUB_DISK_SECTOR_SIZE
				       + GRUB_KERNEL_MACHINE_INSTALL_BSD_PART);
  install_prefix = (core_img + GRUB_DISK_SECTOR_SIZE
		    + GRUB_KERNEL_MACHINE_PREFIX);

  /* Open the root device and the destination device.  */
  root_dev = grub_device_open (root);
  if (! root_dev)
    grub_util_error ("%s", grub_errmsg);

  dest_dev = grub_device_open (dest);
  if (! dest_dev)
    grub_util_error ("%s", grub_errmsg);

  grub_util_info ("setting the root device to `%s'", root);
  if (grub_env_set ("root", root) != GRUB_ERR_NONE)
    grub_util_error ("%s", grub_errmsg);

  /* Read the original sector from the disk.  */
  tmp_img = xmalloc (GRUB_DISK_SECTOR_SIZE);
  if (grub_disk_read (dest_dev->disk, 0, 0, GRUB_DISK_SECTOR_SIZE, tmp_img))
    grub_util_error ("%s", grub_errmsg);

  /* Copy the possible DOS BPB.  */
  memcpy (boot_img + GRUB_BOOT_MACHINE_BPB_START,
	  tmp_img + GRUB_BOOT_MACHINE_BPB_START,
	  GRUB_BOOT_MACHINE_BPB_END - GRUB_BOOT_MACHINE_BPB_START);

  /* Copy the possible partition table.  */
  if (dest_dev->disk->has_partitions)
    memcpy (boot_img + GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
	    tmp_img + GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC,
	    GRUB_BOOT_MACHINE_PART_END - GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC);

  free (tmp_img);
  
  /* If DEST_DRIVE is a hard disk, enable the workaround, which is
     for buggy BIOSes which don't pass boot drive correctly. Instead,
     they pass 0x00 or 0x01 even when booted from 0x80.  */
  if (dest_dev->disk->id & 0x80)
    /* Replace the jmp (2 bytes) with double nop's.  */
    *boot_drive_check = 0x9090;
  
  /* If the destination device can have partitions and it is the MBR,
     try to embed the core image into after the MBR.  */
  if (dest_dev->disk->has_partitions && ! dest_dev->disk->partition)
    {
      grub_partition_iterate (dest_dev->disk, find_first_partition_start);

      /* If there is enough space...  */
      if ((unsigned long) core_sectors + 1 <= first_start)
	{
	  grub_util_info ("will embed the core image into after the MBR");
	  
	  /* The first blocklist contains the whole sectors.  */
	  first_block->start = grub_cpu_to_le32 (2);
	  first_block->len = grub_cpu_to_le16 (core_sectors - 1);
	  first_block->segment
	    = grub_cpu_to_le16 (GRUB_BOOT_MACHINE_KERNEL_SEG
				+ (GRUB_DISK_SECTOR_SIZE >> 4));

	  /* Make sure that the second blocklist is a terminator.  */
	  block = first_block - 1;
	  block->start = 0;
	  block->len = 0;
	  block->segment = 0;

	  /* Embed information about the installed location.  */
	  if (root_dev->disk->partition)
	    {
	      struct grub_pc_partition *pcdata =
		root_dev->disk->partition->data;
	      
	      if (strcmp (root_dev->disk->partition->partmap->name,
			  "pc_partition_map") != 0)
		grub_util_error ("No PC style partitions found");
	      
	      *install_dos_part
		= grub_cpu_to_le32 (pcdata->dos_part);
	      *install_bsd_part
		= grub_cpu_to_le32 (pcdata->bsd_part);
	    }
	  else
	    *install_dos_part = *install_bsd_part = grub_cpu_to_le32 (-1);

	  strcpy (install_prefix, prefix);
	  
	  /* Write the core image onto the disk.  */
	  if (grub_disk_write (dest_dev->disk, 1, 0, core_size, core_img))
	    grub_util_error ("%s", grub_errmsg);

	  /* The boot image and the core image are on the same drive,
	     so there is no need to specify the boot drive explicitly.  */
	  *boot_drive = 0xff;
	  *kernel_sector = grub_cpu_to_le32 (1);

	  /* Write the boot image onto the disk.  */
	  if (grub_disk_write (dest_dev->disk, 0, 0, GRUB_DISK_SECTOR_SIZE,
			       boot_img))
	    grub_util_error ("%s", grub_errmsg);

	  goto finish;
	}
    }
  
  /* The core image must be put on a filesystem unfortunately.  */
  grub_util_info ("will leave the core image on the filesystem");
  
  /* Make sure that GRUB reads the identical image as the OS.  */
  tmp_img = xmalloc (core_size);
  core_path = grub_util_get_path (prefix, core_file);
  
  /* It is a Good Thing to sync two times.  */
  sync ();
  sync ();

#define MAX_TRIES	5
  
  for (i = 0; i < MAX_TRIES; i++)
    {
      grub_util_info ("attempting to read the core image `%s' from GRUB%s",
		      core_path, (i == 0) ? "" : " again");
      
      grub_disk_cache_invalidate_all ();
      
      file = grub_file_open (core_path);
      if (file)
	{
	  if (grub_file_size (file) != (grub_ssize_t) core_size)
	    grub_util_info ("succeeded in opening the core image but the size is different (%d != %d)",
			    (int) grub_file_size (file), (int) core_size);
	  else if (grub_file_read (file, tmp_img, core_size)
		   != (grub_ssize_t) core_size)
	    grub_util_info ("succeeded in opening the core image but cannot read %d bytes",
			    (int) core_size);
	  else if (memcmp (core_img, tmp_img, core_size) != 0)
	    {
#if 0
	      FILE *dump;
	      FILE *dump2;
	      
	      dump = fopen ("dump.img", "wb");
	      if (dump)
		{
		  fwrite (tmp_img, 1, core_size, dump);
		  fclose (dump);
		}