blob: 810906d22b3b0950cae008d30e98e4fdf624c8da [file] [log] [blame]
Ruslan Trofymenko3b7dc912019-07-05 15:37:32 +03001/* 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
9#include <common.h>
10
11/* Android standard boot slot names are 'a', 'b', 'c', ... */
12#define BOOT_SLOT_NAME(slot_num) ('a' + (slot_num))
13
14/* Number of slots */
15#define NUM_SLOTS 2
16
17/**
18 * Select the slot where to boot from.
19 *
20 * On Android devices with more than one boot slot (multiple copies of the
21 * kernel and system images) selects which slot should be used to boot from and
22 * registers the boot attempt. This is used in by the new A/B update model where
23 * one slot is updated in the background while running from the other slot. If
24 * the selected slot did not successfully boot in the past, a boot attempt is
25 * registered before returning from this function so it isn't selected
26 * indefinitely.
27 *
28 * @param[in] dev_desc Place to store the device description pointer
29 * @param[in] part_info Place to store the partition information
30 * @return The slot number (>= 0) on success, or a negative on error
31 */
32int ab_select_slot(struct blk_desc *dev_desc, disk_partition_t *part_info);
33
34#endif /* __ANDROID_AB_H */