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/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef VBOOT_REFERENCE_CGPTLIB_H_
#define VBOOT_REFERENCE_CGPTLIB_H_
#include "sysincludes.h"
enum {
GPT_SUCCESS = 0,
GPT_ERROR_NO_VALID_KERNEL,
GPT_ERROR_INVALID_HEADERS,
GPT_ERROR_INVALID_ENTRIES,
GPT_ERROR_INVALID_SECTOR_SIZE,
GPT_ERROR_INVALID_SECTOR_NUMBER,
GPT_ERROR_INVALID_UPDATE_TYPE,
GPT_ERROR_CRC_CORRUPTED,
GPT_ERROR_OUT_OF_REGION,
GPT_ERROR_START_LBA_OVERLAP,
GPT_ERROR_END_LBA_OVERLAP,
GPT_ERROR_DUP_GUID,
GPT_ERROR_INVALID_FLASH_GEOMETRY,
GPT_ERROR_NO_SUCH_ENTRY,
/* Number of errors */
GPT_ERROR_COUNT
};
/* Bit masks for GptData.modified field. */
#define GPT_MODIFIED_HEADER1 0x01
#define GPT_MODIFIED_HEADER2 0x02
#define GPT_MODIFIED_ENTRIES1 0x04
#define GPT_MODIFIED_ENTRIES2 0x08
/*
* Size of GptData.primary_entries and secondary_entries: 128 bytes/entry * 128
* entries.
*/
#define TOTAL_ENTRIES_SIZE 16384
/*
* The 'update_type' of GptUpdateKernelEntry(). We expose TRY and BAD only
* because those are what verified boot needs. For more precise control on GPT
* attribute bits, please refer to gpt_internal.h.
*/
enum {
/*
* System will be trying to boot the currently selected kernel
* partition. Update its try count if necessary.
*/
GPT_UPDATE_ENTRY_TRY = 1,
/*
* The currently selected kernel partition failed validation. Mark
* entry as invalid.
*/
GPT_UPDATE_ENTRY_BAD = 2,
};
typedef struct {
/* Fill in the following fields before calling GptInit() */
/* GPT primary header, from sector 1 of disk (size: 512 bytes) */
uint8_t *primary_header;
/* GPT secondary header, from last sector of disk (size: 512 bytes) */
uint8_t *secondary_header;
/* Primary GPT table, follows primary header (size: 16 KB) */
uint8_t *primary_entries;
/* Secondary GPT table, precedes secondary header (size: 16 KB) */
uint8_t *secondary_entries;
/* Size of a LBA sector, in bytes */
uint32_t sector_bytes;
/* Size of drive in LBA sectors, in sectors */
uint64_t drive_sectors;
/* Outputs */
/* Which inputs have been modified? GPT_MODIFIED_* */
uint8_t modified;
/*
* The current chromeos kernel index in partition table. -1 means not
* found on drive. Note that GPT partition numbers are traditionally
* 1-based, but we're using a zero-based index here.
*/
int current_kernel;
/* Internal variables */
uint32_t valid_headers, valid_entries;
int current_priority;
} GptData;
/**
* Initializes the GPT data structure's internal state.
*
* The following fields must be filled before calling this function:
*
* primary_header
* secondary_header
* primary_entries
* secondary_entries
* sector_bytes
* drive_sectors
*
* On return the modified field may be set, if the GPT data has been modified
* and should be written to disk.
*
* Returns GPT_SUCCESS if successful, non-zero if error:
* GPT_ERROR_INVALID_HEADERS, both partition table headers are invalid, enters
* recovery mode,
* GPT_ERROR_INVALID_ENTRIES, both partition table entries are invalid, enters
* recovery mode,
* GPT_ERROR_INVALID_SECTOR_SIZE, size of a sector is not supported,
* GPT_ERROR_INVALID_SECTOR_NUMBER, number of sectors in drive is invalid (too
* small) */
int GptInit(GptData *gpt);
/**
* Provides the location of the next kernel partition, in order of decreasing
* priority.
*
* On return the start_sector parameter contains the LBA sector for the start
* of the kernel partition, and the size parameter contains the size of the
* kernel partition in LBA sectors. gpt.current_kernel contains the partition
* index of the current chromeos kernel partition.
*
* Returns GPT_SUCCESS if successful, else
* GPT_ERROR_NO_VALID_KERNEL, no avaliable kernel, enters recovery mode */
int GptNextKernelEntry(GptData *gpt, uint64_t *start_sector, uint64_t *size);
/**
* Updates the kernel entry with the specified index, using the specified type
* of update (GPT_UPDATE_ENTRY_*).
*
* On return the modified field may be set, if the GPT data has been modified
* and should be written to disk.
*
* Returns GPT_SUCCESS if successful, else
* GPT_ERROR_INVALID_UPDATE_TYPE, invalid 'update_type' is given.
*/
int GptUpdateKernelEntry(GptData *gpt, uint32_t update_type);
#endif /* VBOOT_REFERENCE_CGPTLIB_H_ */
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