From b38a4983949bbf66a7ecdae3423b2401ce2e635f Mon Sep 17 00:00:00 2001 From: Vladimir 'phcoder' Serbinenko Date: Tue, 5 Apr 2011 14:40:15 +0200 Subject: [PATCH] BPB patching support (untested) --- grub-core/fs/fat.c | 47 +------------ grub-core/loader/i386/pc/chainloader.c | 91 ++++++++++++++++++++++++-- grub-core/loader/i386/pc/ntldr.c | 2 + grub-core/normal/main.c | 3 + include/grub/i386/pc/chainloader.h | 7 +- include/grub/ntfs.h | 8 ++- 6 files changed, 99 insertions(+), 59 deletions(-) diff --git a/grub-core/fs/fat.c b/grub-core/fs/fat.c index 89050943c..7906cf1b2 100644 --- a/grub-core/fs/fat.c +++ b/grub-core/fs/fat.c @@ -26,6 +26,7 @@ #include #include #include +#include #define GRUB_FAT_DIR_ENTRY_SIZE 32 @@ -49,52 +50,6 @@ | GRUB_FAT_ATTR_ARCHIVE \ | GRUB_FAT_ATTR_VOLUME_ID) -struct grub_fat_bpb -{ - grub_uint8_t jmp_boot[3]; - grub_uint8_t oem_name[8]; - grub_uint16_t bytes_per_sector; - grub_uint8_t sectors_per_cluster; - grub_uint16_t num_reserved_sectors; - grub_uint8_t num_fats; - grub_uint16_t num_root_entries; - grub_uint16_t num_total_sectors_16; - grub_uint8_t media; - grub_uint16_t sectors_per_fat_16; - grub_uint16_t sectors_per_track; - grub_uint16_t num_heads; - grub_uint32_t num_hidden_sectors; - grub_uint32_t num_total_sectors_32; - union - { - struct - { - grub_uint8_t num_ph_drive; - grub_uint8_t reserved; - grub_uint8_t boot_sig; - grub_uint32_t num_serial; - grub_uint8_t label[11]; - grub_uint8_t fstype[8]; - } __attribute__ ((packed)) fat12_or_fat16; - struct - { - grub_uint32_t sectors_per_fat_32; - grub_uint16_t extended_flags; - grub_uint16_t fs_version; - grub_uint32_t root_cluster; - grub_uint16_t fs_info; - grub_uint16_t backup_boot_sector; - grub_uint8_t reserved[12]; - grub_uint8_t num_ph_drive; - grub_uint8_t reserved1; - grub_uint8_t boot_sig; - grub_uint32_t num_serial; - grub_uint8_t label[11]; - grub_uint8_t fstype[8]; - } __attribute__ ((packed)) fat32; - } __attribute__ ((packed)) version_specific; -} __attribute__ ((packed)); - struct grub_fat_dir_entry { grub_uint8_t name[11]; diff --git a/grub-core/loader/i386/pc/chainloader.c b/grub-core/loader/i386/pc/chainloader.c index fd99c81d5..174e5b7a5 100644 --- a/grub-core/loader/i386/pc/chainloader.c +++ b/grub-core/loader/i386/pc/chainloader.c @@ -37,11 +37,19 @@ #include #include #include +#include +#include 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; } diff --git a/grub-core/loader/i386/pc/ntldr.c b/grub-core/loader/i386/pc/ntldr.c index 0c33a0680..9649cdfbe 100644 --- a/grub-core/loader/i386/pc/ntldr.c +++ b/grub-core/loader/i386/pc/ntldr.c @@ -32,6 +32,7 @@ #include #include #include +#include static grub_dl_t my_mod; static struct grub_relocator *rel; @@ -110,6 +111,7 @@ grub_cmd_ntldr (grub_command_t cmd __attribute__ ((unused)), grub_device_close (dev); goto fail; } + grub_chainloader_patch_bpb (bs, dev, edx); } if (dev) diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c index cefb1cb9b..c04accb6d 100644 --- a/grub-core/normal/main.c +++ b/grub-core/normal/main.c @@ -515,6 +515,9 @@ GRUB_MOD_INIT(normal) /* Set default color names. */ grub_env_set ("color_normal", "white/black"); grub_env_set ("color_highlight", "black/white"); + + grub_env_set ("grub_feature_chainloader_bpb", "--bpb"); + grub_env_export ("grub_feature_chainloader_bpb"); } GRUB_MOD_FINI(normal) diff --git a/include/grub/i386/pc/chainloader.h b/include/grub/i386/pc/chainloader.h index ca1da23a7..4776b181b 100644 --- a/include/grub/i386/pc/chainloader.h +++ b/include/grub/i386/pc/chainloader.h @@ -21,10 +21,7 @@ #include -/* Common function for normal and rescue mode commands. */ -typedef enum - { - GRUB_CHAINLOADER_FORCE = 0x1 - } grub_chainloader_flags_t; +void +grub_chainloader_patch_bpb (void *bs, grub_device_t dev, grub_uint8_t dl); #endif /* GRUB_CHAINLOADER_MACHINE_HEADER */ diff --git a/include/grub/ntfs.h b/include/grub/ntfs.h index 31b99398b..9e2e34707 100644 --- a/include/grub/ntfs.h +++ b/include/grub/ntfs.h @@ -106,14 +106,16 @@ struct grub_ntfs_bpb grub_uint16_t sectors_per_track; grub_uint16_t num_heads; grub_uint32_t num_hidden_sectors; - grub_uint32_t reserved_3[2]; + grub_uint32_t reserved_3; + grub_uint8_t bios_drive; + grub_uint8_t reserved_4[3]; grub_uint64_t num_total_sectors; grub_uint64_t mft_lcn; grub_uint64_t mft_mirr_lcn; grub_int8_t clusters_per_mft; - grub_int8_t reserved_4[3]; - grub_int8_t clusters_per_index; grub_int8_t reserved_5[3]; + grub_int8_t clusters_per_index; + grub_int8_t reserved_6[3]; grub_uint64_t num_serial; grub_uint32_t checksum; } __attribute__ ((packed));