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 
9 #include <stdbool.h>
10 
11 struct blk_desc;
12 struct disk_partition;
13 
14 /* Android standard boot slot names are 'a', 'b', 'c', ... */
15 #define BOOT_SLOT_NAME(slot_num) ('a' + (slot_num))
16 
17 /* Number of slots */
18 #define NUM_SLOTS 2
19 
20 /**
21  * ab_select_slot() - Select the slot where to boot from.
22  *
23  * @dev_desc: Place to store the device description pointer
24  * @part_info: Place to store the partition information
25  *
26  * On Android devices with more than one boot slot (multiple copies of the
27  * kernel and system images) selects which slot should be used to boot from and
28  * registers the boot attempt. This is used in by the new A/B update model where
29  * one slot is updated in the background while running from the other slot. If
30  * the selected slot did not successfully boot in the past, a boot attempt is
31  * registered before returning from this function so it isn't selected
32  * indefinitely.
33  *
34  * Return: The slot number (>= 0) on success, or a negative on error
35  */
36 int ab_select_slot(struct blk_desc *dev_desc, struct disk_partition *part_info,
37                    bool dec_tries);
38 
39 /**
40  * ab_dump_abc() - Dump ABC information for specific partition.
41  *
42  * @dev_desc: Device description pointer
43  * @part_info: Partition information
44  *
45  * Return: 0 on success, or a negative on error
46  */
47 int ab_dump_abc(struct blk_desc *dev_desc, struct disk_partition *part_info);
48 
49 #endif /* __ANDROID_AB_H */
50