qbootctl/gpt-utils.h

/*
 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of The Linux Foundation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __GPT_UTILS_H__
#define __GPT_UTILS_H__
#ifdef __cplusplus
extern "C" {
#endif
#include <unistd.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include <linux/limits.h>

#define GPT_SIGNATURE		"EFI PART"
#define HEADER_SIZE_OFFSET	12
#define HEADER_CRC_OFFSET	16
#define PRIMARY_HEADER_OFFSET	24
#define BACKUP_HEADER_OFFSET	32
#define FIRST_USABLE_LBA_OFFSET 40
#define LAST_USABLE_LBA_OFFSET	48
#define PENTRIES_OFFSET		72
#define PARTITION_COUNT_OFFSET	80
#define PENTRY_SIZE_OFFSET	84
#define PARTITION_CRC_OFFSET	88

#define TYPE_GUID_OFFSET	0
#define TYPE_GUID_SIZE		16
#define PTN_ENTRY_SIZE		128
#define UNIQUE_GUID_OFFSET	16
#define FIRST_LBA_OFFSET	32
#define LAST_LBA_OFFSET		40
#define ATTRIBUTE_FLAG_OFFSET	48
#define PARTITION_NAME_OFFSET	56
#define MAX_GPT_NAME_SIZE	72

// Bit 48 onwords in the attribute field are the ones where we are allowed to
// store our AB attributes.
#define AB_FLAG_OFFSET			  (ATTRIBUTE_FLAG_OFFSET + 6)
#define GPT_DISK_INIT_MAGIC		  0xABCD
#define AB_PARTITION_ATTR_SLOT_ACTIVE	  (0x1 << 2)
#define AB_PARTITION_ATTR_BOOT_SUCCESSFUL (0x1 << 6)
#define AB_PARTITION_ATTR_UNBOOTABLE	  (0x1 << 7)
#define AB_SLOT_ACTIVE_VAL		  0xF
#define AB_SLOT_INACTIVE_VAL		  0x0
#define AB_SLOT_ACTIVE			  1
#define AB_SLOT_INACTIVE		  0
#define AB_SLOT_A_SUFFIX		  "_a"
#define AB_SLOT_B_SUFFIX		  "_b"
#define PTN_XBL				  "xbl"
// XBL is not included because the slot attributes are meaningless there
// *which* XBL partition is active is determined via the UFS bBootLunEn field
// as it needs to be handled by PBL
#define PTN_SWAP_LIST \
	"abl_a", "aop_a", "apdp_a", "cmnlib_a", "cmnlib64_a", "devcfg_a", "dtbo_a", \
	"hyp_a", "keymaster_a", "msadp_a", "qupfw_a", "storsec_a", "tz_a", \
	"vbmeta_a", "vbmeta_system_a"

static const char g_all_ptns[][MAX_GPT_NAME_SIZE + 1] = {
	PTN_SWAP_LIST, "boot_a", "system_a",
	"vendor_a", "modem_a", "system_ext_a", "product_a"
};

// No more than /dev/sdk
#define MAX_BLOCK_DEVICES 10

#define BOOT_DEV_DIR  "/dev/disk/by-partlabel"

#define GPT_PTN_PATH_MAX sizeof(BOOT_DEV_DIR) + MAX_GPT_NAME_SIZE + 2

#define EMMC_DEVICE "/dev/mmcblk0"

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

enum gpt_instance { PRIMARY_GPT = 0, SECONDARY_GPT };

enum boot_chain { NORMAL_BOOT = 0, BACKUP_BOOT };

struct gpt_disk {
	// GPT primary header
	uint8_t *hdr;
	// primary header crc
	uint32_t hdr_crc;
	// GPT backup header
	uint8_t *hdr_bak;
	// backup header crc
	uint32_t hdr_bak_crc;
	// Partition entries array
	uint8_t *pentry_arr;
	// Partition entries array for backup table
	uint8_t *pentry_arr_bak;
	// Size of the pentry array
	uint32_t pentry_arr_size;
	// Size of each element in the pentry array
	uint32_t pentry_size;
	// CRC of the partition entry array
	uint32_t pentry_arr_crc;
	// CRC of the backup partition entry array
	uint32_t pentry_arr_bak_crc;
	// Path to block dev representing the disk
	char devpath[PATH_MAX];
	// Block size of disk
	uint32_t block_size;
	uint32_t is_initialized;
};

// GPT disk methods
bool gpt_disk_is_valid(struct gpt_disk *disk);
// Free previously allocated gpt_disk struct
void gpt_disk_free(struct gpt_disk *disk);
// Get the details of the disk holding the partition whose name
// is passed in via dev
int gpt_disk_get_disk_info(const char *dev, struct gpt_disk *disk);

int partition_is_for_disk(const struct gpt_disk *disk, const char *part, char *blockdev, int blockdev_len);

// Get pointer to partition entry from a allocated gpt_disk structure
uint8_t *gpt_disk_get_pentry(struct gpt_disk *disk, const char *partname,
			     enum gpt_instance instance);

// Write the contents of struct gpt_disk back to the actual disk
int gpt_disk_commit(struct gpt_disk *disk);

// Swtich betwieen using either the primary or the backup
// boot LUN for boot. This is required since UFS boot partitions
// cannot have a backup GPT which is what we use for failsafe
// updates of the other 'critical' partitions. This function will
// not be invoked for emmc targets and on UFS targets is only required
// to be invoked for XBL.
//
// The algorithm to do this is as follows:
// - Find the real block device(eg: /dev/block/sdb) that corresponds
//  to the /dev/block/bootdevice/by-name/xbl(bak) symlink
//
// - Once we have the block device 'node' name(sdb in the above example)
//  use this node to to locate the scsi generic device that represents
//  it by checking the file /sys/block/sdb/device/scsi_generic/sgY
//
// - Once we locate sgY we call the query ioctl on /dev/sgy to switch
// the boot lun to either LUNA or LUNB
int gpt_utils_set_xbl_boot_partition(enum boot_chain chain);

bool gpt_utils_is_partition_backed_by_emmc(const char *part);
#ifdef __cplusplus
}
#endif
#endif /* __GPT_UTILS_H__ */