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gpt: start new GPT module

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This module is a new implementation for reading GUID Partition Tables
which is much stricter than the existing part_gpt module and exports GPT
data directly instead of the generic grub_partition structure. It will
be the basis for modules that need to read/write/update GPT data.

The current code does nothing more than read and verify the table.
This commit is contained in:
Michael Marineau 2014-09-28 21:26:21 -07:00
parent 28b0af948e
commit f82f65f338
6 changed files with 837 additions and 0 deletions
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60
include/grub/gpt_partition.h
View file

@ -21,6 +21,7 @@
#include <grub/types.h>
#include <grub/partition.h>
#include <grub/msdos_partition.h>
struct grub_gpt_part_type
{
@ -50,6 +51,12 @@ typedef struct grub_gpt_part_type grub_gpt_part_type_t;
{ 0x85, 0xD2, 0xE1, 0xE9, 0x04, 0x34, 0xCF, 0xB3 } \
}
#define GRUB_GPT_HEADER_MAGIC \
{ 0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54 }
#define GRUB_GPT_HEADER_VERSION \
grub_cpu_to_le32_compile_time (0x00010000U)
struct grub_gpt_header
{
grub_uint8_t magic[8];
@ -78,10 +85,63 @@ struct grub_gpt_partentry
char name[72];
} GRUB_PACKED;
/* Basic GPT partmap module. */
grub_err_t
grub_gpt_partition_map_iterate (grub_disk_t disk,
grub_partition_iterate_hook_t hook,
void *hook_data);
/* Advanced GPT library. */
typedef enum grub_gpt_status
{
GRUB_GPT_PROTECTIVE_MBR = 0x01,
GRUB_GPT_HYBRID_MBR = 0x02,
GRUB_GPT_PRIMARY_HEADER_VALID = 0x04,
GRUB_GPT_PRIMARY_ENTRIES_VALID = 0x08,
GRUB_GPT_BACKUP_HEADER_VALID = 0x10,
GRUB_GPT_BACKUP_ENTRIES_VALID = 0x20,
} grub_gpt_status_t;
#define GRUB_GPT_MBR_VALID (GRUB_GPT_PROTECTIVE_MBR|GRUB_GPT_HYBRID_MBR)
/* UEFI requires the entries table to be at least 16384 bytes for a
* total of 128 entries given the standard 128 byte entry size. */
#define GRUB_GPT_DEFAULT_ENTRIES_LENGTH 128
struct grub_gpt
{
/* Bit field indicating which structures on disk are valid. */
grub_gpt_status_t status;
/* Protective or hybrid MBR. */
struct grub_msdos_partition_mbr mbr;
/* Each of the two GPT headers. */
struct grub_gpt_header primary;
struct grub_gpt_header backup;
/* Only need one entries table, on disk both copies are identical. */
struct grub_gpt_partentry *entries;
/* Logarithm of sector size, in case GPT and disk driver disagree. */
unsigned int log_sector_size;
};
typedef struct grub_gpt *grub_gpt_t;
/* Translate GPT sectors to GRUB's 512 byte block addresses. */
static inline grub_disk_addr_t
grub_gpt_sector_to_addr (grub_gpt_t gpt, grub_uint64_t sector)
{
return (sector << (gpt->log_sector_size - GRUB_DISK_SECTOR_BITS));
}
/* Allocates and fills new grub_gpt structure, free with grub_gpt_free. */
grub_gpt_t grub_gpt_read (grub_disk_t disk);
void grub_gpt_free (grub_gpt_t gpt);
grub_err_t grub_gpt_pmbr_check (struct grub_msdos_partition_mbr *mbr);
grub_err_t grub_gpt_header_check (struct grub_gpt_header *gpt,
unsigned int log_sector_size);
#endif /* ! GRUB_GPT_PARTITION_HEADER */