1/* SPDX-License-Identifier: BSD-2-Clause */ 2/* 3 * Copyright (C) 2017 The Android Open Source Project 4 */ 5 6#ifndef __ANDROID_AB_H 7#define __ANDROID_AB_H 8 9struct blk_desc; 10struct disk_partition; 11 12/* Android standard boot slot names are 'a', 'b', 'c', ... */ 13#define BOOT_SLOT_NAME(slot_num) ('a' + (slot_num)) 14 15/* Number of slots */ 16#define NUM_SLOTS 2 17 18/** 19 * Select the slot where to boot from. 20 * 21 * On Android devices with more than one boot slot (multiple copies of the 22 * kernel and system images) selects which slot should be used to boot from and 23 * registers the boot attempt. This is used in by the new A/B update model where 24 * one slot is updated in the background while running from the other slot. If 25 * the selected slot did not successfully boot in the past, a boot attempt is 26 * registered before returning from this function so it isn't selected 27 * indefinitely. 28 * 29 * @param[in] dev_desc Place to store the device description pointer 30 * @param[in] part_info Place to store the partition information 31 * Return: The slot number (>= 0) on success, or a negative on error 32 */ 33int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info, 34 bool dec_tries); 35 36#endif /* __ANDROID_AB_H */ 37