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426 lines
12 KiB
C
426 lines
12 KiB
C
/* pc.c - Read PC style partition tables. */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2002,2004,2005,2006,2007,2008,2009 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/partition.h>
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#include <grub/msdos_partition.h>
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#include <grub/disk.h>
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#include <grub/mm.h>
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#include <grub/misc.h>
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#include <grub/dl.h>
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#include <grub/i18n.h>
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GRUB_MOD_LICENSE ("GPLv3+");
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static struct grub_partition_map grub_msdos_partition_map;
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#ifdef GRUB_UTIL
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#include <grub/emu/misc.h>
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struct embed_signature
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{
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const char *name;
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const char *signature;
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int signature_len;
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enum { TYPE_SOFTWARE, TYPE_RAID } type;
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};
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const char message_warn[][200] = {
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/* TRANSLATORS: MBR gap and boot track is the same thing and is the space
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between MBR and first partitition. If your language translates well only
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"boot track", you can just use it everywhere. Next two messages are about
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RAID controllers/software bugs which GRUB has to live with. Please spread
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the message that these are bugs in other software and not merely
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suboptimal behaviour. */
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[TYPE_RAID] = N_("Sector %llu is already in use by raid controller `%s';"
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" avoiding it. "
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"Please ask the manufacturer not to store data in MBR gap"),
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[TYPE_SOFTWARE] = N_("Sector %llu is already in use by the program `%s';"
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" avoiding it. "
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"This software may cause boot or other problems in "
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"future. Please ask its authors not to store data "
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"in the boot track")
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};
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/* Signatures of other software that may be using sectors in the embedding
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area. */
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struct embed_signature embed_signatures[] =
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{
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{
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.name = "ZISD",
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.signature = "ZISD",
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.signature_len = 4,
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.type = TYPE_SOFTWARE
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},
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{
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.name = "FlexNet",
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.signature = "\xd4\x41\xa0\xf5\x03\x00\x03\x00",
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.signature_len = 8,
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.type = TYPE_SOFTWARE
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},
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{
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.name = "FlexNet",
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.signature = "\xd8\x41\xa0\xf5\x02\x00\x02\x00",
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.signature_len = 8,
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.type = TYPE_SOFTWARE
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},
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{
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/* from Ryan Perkins */
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.name = "HP Backup and Recovery Manager (?)",
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.signature = "\x70\x8a\x5d\x46\x35\xc5\x1b\x93"
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"\xae\x3d\x86\xfd\xb1\x55\x3e\xe0",
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.signature_len = 16,
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.type = TYPE_SOFTWARE
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},
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{
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.name = "HighPoint RAID controller",
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.signature = "ycgl",
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.signature_len = 4,
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.type = TYPE_RAID
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},
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{
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/* https://bugs.launchpad.net/bugs/987022 */
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.name = "Acer registration utility (?)",
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.signature = "GREGRegDone.Tag\x00",
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.signature_len = 16,
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.type = TYPE_SOFTWARE
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}
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};
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#endif
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grub_err_t
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grub_partition_msdos_iterate (grub_disk_t disk,
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grub_partition_iterate_hook_t hook,
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void *hook_data)
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{
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struct grub_partition p;
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struct grub_msdos_partition_mbr mbr;
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int labeln = 0;
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grub_disk_addr_t lastaddr;
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grub_disk_addr_t ext_offset;
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grub_disk_addr_t delta = 0;
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if (disk->partition && disk->partition->partmap == &grub_msdos_partition_map)
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{
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if (disk->partition->msdostype == GRUB_PC_PARTITION_TYPE_LINUX_MINIX)
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delta = disk->partition->start;
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else
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "no embedding supported");
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}
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p.offset = 0;
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ext_offset = 0;
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p.number = -1;
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p.partmap = &grub_msdos_partition_map;
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/* Any value different than `p.offset' will satisfy the check during
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first loop. */
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lastaddr = !p.offset;
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while (1)
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{
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int i;
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struct grub_msdos_partition_entry *e;
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/* Read the MBR. */
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if (grub_disk_read (disk, p.offset, 0, sizeof (mbr), &mbr))
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goto finish;
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/* If this is a GPT partition, this MBR is just a dummy. */
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if (p.offset == 0)
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for (i = 0; i < 4; i++)
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if (mbr.entries[i].type == GRUB_PC_PARTITION_TYPE_GPT_DISK)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr");
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/* This is our loop-detection algorithm. It works the following way:
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It saves last position which was a power of two. Then it compares the
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saved value with a current one. This way it's guaranteed that the loop
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will be broken by at most third walk.
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*/
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if (labeln && lastaddr == p.offset)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "loop detected");
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labeln++;
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if ((labeln & (labeln - 1)) == 0)
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lastaddr = p.offset;
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/* Check if it is valid. */
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if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
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for (i = 0; i < 4; i++)
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if (mbr.entries[i].flag & 0x7f)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "bad boot flag");
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/* Analyze DOS partitions. */
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for (p.index = 0; p.index < 4; p.index++)
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{
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e = mbr.entries + p.index;
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p.start = p.offset
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+ (grub_le_to_cpu32 (e->start)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) - delta;
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p.len = grub_le_to_cpu32 (e->length)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS);
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p.msdostype = e->type;
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grub_dprintf ("partition",
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"partition %d: flag 0x%x, type 0x%x, start 0x%llx, len 0x%llx\n",
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p.index, e->flag, e->type,
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(unsigned long long) p.start,
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(unsigned long long) p.len);
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/* If this partition is a normal one, call the hook. */
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if (! grub_msdos_partition_is_empty (e->type)
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&& ! grub_msdos_partition_is_extended (e->type))
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{
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p.number++;
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if (hook (disk, &p, hook_data))
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return grub_errno;
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}
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else if (p.number < 3)
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/* If this partition is a logical one, shouldn't increase the
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partition number. */
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p.number++;
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}
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/* Find an extended partition. */
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for (i = 0; i < 4; i++)
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{
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e = mbr.entries + i;
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if (grub_msdos_partition_is_extended (e->type))
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{
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p.offset = ext_offset
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+ (grub_le_to_cpu32 (e->start)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
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if (! ext_offset)
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ext_offset = p.offset;
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break;
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}
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}
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/* If no extended partition, the end. */
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if (i == 4)
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break;
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}
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finish:
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return grub_errno;
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}
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#ifdef GRUB_UTIL
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static grub_err_t
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pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors,
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unsigned int max_nsectors,
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grub_embed_type_t embed_type,
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grub_disk_addr_t **sectors)
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{
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grub_disk_addr_t end = ~0ULL;
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struct grub_msdos_partition_mbr mbr;
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int labeln = 0;
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/* Any value different than `p.offset' will satisfy the check during
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first loop. */
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grub_disk_addr_t lastaddr = 1;
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grub_disk_addr_t ext_offset = 0;
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grub_disk_addr_t offset = 0;
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if (embed_type != GRUB_EMBED_PCBIOS)
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return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
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"PC-style partitions curently support "
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"only PC-BIOS embedding");
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if (disk->partition)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
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"Embedding on MSDOS subpartition isn't supported");
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while (1)
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{
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int i;
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struct grub_msdos_partition_entry *e;
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grub_err_t err;
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/* Read the MBR. */
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err = grub_disk_read (disk, offset, 0, sizeof (mbr), &mbr);
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if (err)
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return err;
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/* This is our loop-detection algorithm. It works the following way:
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It saves last position which was a power of two. Then it compares the
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saved value with a current one. This way it's guaranteed that the loop
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will be broken by at most third walk.
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*/
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if (labeln && lastaddr == offset)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "loop detected");
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labeln++;
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if ((labeln & (labeln - 1)) == 0)
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lastaddr = offset;
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/* Check if it is valid. */
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if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
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for (i = 0; i < 4; i++)
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if (mbr.entries[i].flag & 0x7f)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "bad boot flag");
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/* Analyze DOS partitions. */
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for (i = 0; i < 4; i++)
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{
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e = mbr.entries + i;
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if (!grub_msdos_partition_is_empty (e->type)
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&& end > offset
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+ (grub_le_to_cpu32 (e->start)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)))
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end = offset + (grub_le_to_cpu32 (e->start)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
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/* If this is a GPT partition, this MBR is just a dummy. */
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if (e->type == GRUB_PC_PARTITION_TYPE_GPT_DISK && i == 0)
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return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr");
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}
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/* Find an extended partition. */
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for (i = 0; i < 4; i++)
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{
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e = mbr.entries + i;
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if (grub_msdos_partition_is_extended (e->type))
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{
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offset = ext_offset
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+ (grub_le_to_cpu32 (e->start)
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<< (disk->log_sector_size - GRUB_DISK_SECTOR_BITS));
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if (! ext_offset)
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ext_offset = offset;
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break;
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}
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}
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/* If no extended partition, the end. */
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if (i == 4)
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break;
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}
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if (end >= *nsectors + 1)
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{
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unsigned i, j;
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char *embed_signature_check;
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unsigned int orig_nsectors, avail_nsectors;
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orig_nsectors = *nsectors;
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*nsectors = end - 1;
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avail_nsectors = *nsectors;
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if (*nsectors > max_nsectors)
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*nsectors = max_nsectors;
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*sectors = grub_malloc (*nsectors * sizeof (**sectors));
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if (!*sectors)
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return grub_errno;
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for (i = 0; i < *nsectors; i++)
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(*sectors)[i] = 1 + i;
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/* Check for software that is already using parts of the embedding
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* area.
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*/
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embed_signature_check = grub_malloc (GRUB_DISK_SECTOR_SIZE);
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for (i = 0; i < *nsectors; i++)
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{
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if (grub_disk_read (disk, (*sectors)[i], 0, GRUB_DISK_SECTOR_SIZE,
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embed_signature_check))
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continue;
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for (j = 0; j < ARRAY_SIZE (embed_signatures); j++)
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if (! grub_memcmp (embed_signatures[j].signature,
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embed_signature_check,
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embed_signatures[j].signature_len))
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break;
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if (j == ARRAY_SIZE (embed_signatures))
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continue;
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grub_util_warn (_(message_warn[embed_signatures[j].type]),
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(*sectors)[i], embed_signatures[j].name);
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avail_nsectors--;
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if (avail_nsectors < *nsectors)
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*nsectors = avail_nsectors;
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/* Avoid this sector. */
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for (j = i; j < *nsectors; j++)
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(*sectors)[j]++;
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/* Have we run out of space? */
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if (avail_nsectors < orig_nsectors)
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break;
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/* Make sure to check the next sector. */
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i--;
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}
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grub_free (embed_signature_check);
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if (*nsectors < orig_nsectors)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
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N_("other software is using the embedding area, and "
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"there is not enough room for core.img. Such "
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"software is often trying to store data in a way "
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"that avoids detection. We recommend you "
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"investigate"));
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return GRUB_ERR_NONE;
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}
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if (end <= 1)
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return grub_error (GRUB_ERR_FILE_NOT_FOUND,
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N_("this msdos-style partition label has no "
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"post-MBR gap; embedding won't be possible"));
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if (*nsectors > 62)
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
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N_("your core.img is unusually large. "
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"It won't fit in the embedding area"));
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return grub_error (GRUB_ERR_OUT_OF_RANGE,
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N_("your embedding area is unusually small. "
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"core.img won't fit in it."));
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}
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#endif
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/* Partition map type. */
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static struct grub_partition_map grub_msdos_partition_map =
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{
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.name = "msdos",
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.iterate = grub_partition_msdos_iterate,
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#ifdef GRUB_UTIL
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.embed = pc_partition_map_embed
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#endif
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};
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GRUB_MOD_INIT(part_msdos)
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{
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grub_partition_map_register (&grub_msdos_partition_map);
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}
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GRUB_MOD_FINI(part_msdos)
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{
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grub_partition_map_unregister (&grub_msdos_partition_map);
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}
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