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BPB patching support (untested)

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2011-04-05 14:40:15 +02:00
parent 850e937329
commit b38a498394
6 changed files with 99 additions and 59 deletions
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91
grub-core/loader/i386/pc/chainloader.c
View file

@ -37,11 +37,19 @@
#include <grub/i18n.h>
#include <grub/video.h>
#include <grub/mm.h>
#include <grub/fat.h>
#include <grub/ntfs.h>
static grub_dl_t my_mod;
static int boot_drive;
static void *boot_part_addr;
typedef enum
{
GRUB_CHAINLOADER_FORCE = 0x1,
GRUB_CHAINLOADER_BPB = 0x2,
} grub_chainloader_flags_t;
static grub_err_t
grub_chainloader_boot (void)
{
@ -59,6 +67,63 @@ grub_chainloader_unload (void)
return GRUB_ERR_NONE;
}
void
grub_chainloader_patch_bpb (void *bs, grub_device_t dev, grub_uint8_t dl)
{
grub_uint32_t part_start = 0;
if (dev && dev->disk)
part_start = grub_partition_get_start (dev->disk->partition);
if (grub_memcmp ((char *) &((struct grub_ntfs_bpb *) bs)->oem_name,
"NTFS", 4) == 0)
{
struct grub_ntfs_bpb *bpb = (struct grub_ntfs_bpb *) bs;
bpb->num_hidden_sectors = grub_cpu_to_le32 (part_start);
bpb->bios_drive = dl;
return;
}
do
{
struct grub_fat_bpb *bpb = (struct grub_fat_bpb *) bs;
if (grub_strncmp((const char *) bpb->version_specific.fat12_or_fat16.fstype, "FAT12", 5)
&& grub_strncmp((const char *) bpb->version_specific.fat12_or_fat16.fstype, "FAT16", 5)
&& grub_strncmp((const char *) bpb->version_specific.fat32.fstype, "FAT32", 5))
break;
if (grub_le_to_cpu16 (bpb->bytes_per_sector) < 512
|| (grub_le_to_cpu16 (bpb->bytes_per_sector)
& (grub_le_to_cpu16 (bpb->bytes_per_sector) - 1)))
break;
if (bpb->sectors_per_cluster == 0
|| (bpb->sectors_per_cluster & (bpb->sectors_per_cluster - 1)))
break;
if (bpb->num_reserved_sectors == 0)
break;
if (bpb->num_total_sectors_16 == 0 || bpb->num_total_sectors_32 == 0)
break;
if (bpb->num_fats == 0)
break;
if (bpb->sectors_per_fat_16)
{
bpb->num_hidden_sectors = grub_cpu_to_le32 (part_start);
bpb->version_specific.fat12_or_fat16.num_ph_drive = dl;
return;
}
if (bpb->version_specific.fat32.sectors_per_fat_32)
{
bpb->num_hidden_sectors = grub_cpu_to_le32 (part_start);
bpb->version_specific.fat32.num_ph_drive = dl;
return;
}
break;
}
while (0);
}
static void
grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
{
@ -119,6 +184,9 @@ grub_chainloader_cmd (const char *filename, grub_chainloader_flags_t flags)
}
}
if (flags & GRUB_CHAINLOADER_BPB)
grub_chainloader_patch_bpb ((void *) 0x7C00, dev, drive);
if (dev)
grub_device_close (dev);
@ -145,11 +213,23 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
{
grub_chainloader_flags_t flags = 0;
if (argc > 0 && grub_strcmp (argv[0], "--force") == 0)
while (argc > 0)
{
flags |= GRUB_CHAINLOADER_FORCE;
argc--;
argv++;
if (grub_strcmp (argv[0], "--force") == 0)
{
flags |= GRUB_CHAINLOADER_FORCE;
argc--;
argv++;
continue;
}
if (grub_strcmp (argv[0], "--bpb") == 0)
{
flags |= GRUB_CHAINLOADER_BPB;
argc--;
argv++;
continue;
}
break;
}
if (argc == 0)
@ -165,7 +245,8 @@ static grub_command_t cmd;
GRUB_MOD_INIT(chainloader)
{
cmd = grub_register_command ("chainloader", grub_cmd_chainloader,
0, N_("Load another boot loader."));
"[--force|--bpb] FILE",
N_("Load another boot loader."));
my_mod = mod;
}