1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H
#define ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H
#include <hardware/hardware.h>
__BEGIN_DECLS
#define BOOT_CONTROL_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1)
/**
* The id of this module
*/
#define BOOT_CONTROL_HARDWARE_MODULE_ID "bootctrl"
/*
* The Boot Control HAL is designed to allow for managing sets of redundant
* partitions, called slots, that can be booted from independantly. Slots
* are sets of partitions whose names differ only by a given suffix.
* They are identified here by a 0 indexed number, and associated with their
* suffix, which can be appended to the base name for any particular partition
* to find the one associated with that slot. The bootloader must pass the suffix
* of the currently active slot either through a kernel command line property at
* androidboot.slot_suffix, or the device tree at /firmware/android/slot_suffix.
* The primary use of this set up is to allow for background updates while the
* device is running, and to provide a fallback in the event that the update fails.
*/
/**
* Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
* and the fields of this data structure must begin with hw_module_t
* followed by module specific information.
*/
typedef struct boot_control_module {
struct hw_module_t common;
/*
* (*init)() perform any initialization tasks needed for the HAL.
* This is called only once.
*/
void (*init)(struct boot_control_module *module);
/*
* (*getNumberSlots)() returns the number of available slots.
* For instance, a system with a single set of partitions would return
* 1, a system with A/B would return 2, A/B/C -> 3...
*/
unsigned (*getNumberSlots)(struct boot_control_module *module);
/*
* (*getCurrentSlot)() returns the value letting the system know
* whether the current slot is A or B. The meaning of A and B is
* left up to the implementer. It is assumed that if the current slot
* is A, then the block devices underlying B can be accessed directly
* without any risk of corruption.
* The returned value is always guaranteed to be strictly less than the
* value returned by getNumberSlots. Slots start at 0 and
* finish at getNumberSlots() - 1
*/
unsigned (*getCurrentSlot)(struct boot_control_module *module);
/*
* (*markBootSuccessful)() marks the current slot
* as having booted successfully
*
* Returns 0 on success, -errno on error.
*/
int (*markBootSuccessful)(struct boot_control_module *module);
/*
* (*setActiveBootSlot)() marks the slot passed in parameter as
* the active boot slot (see getCurrentSlot for an explanation
* of the "slot" parameter). This overrides any previous call to
* setSlotAsUnbootable.
* Returns 0 on success, -errno on error.
*/
int (*setActiveBootSlot)(struct boot_control_module *module, unsigned slot);
/*
* (*setSlotAsUnbootable)() marks the slot passed in parameter as
* an unbootable. This can be used while updating the contents of the slot's
* partitions, so that the system will not attempt to boot a known bad set up.
* Returns 0 on success, -errno on error.
*/
int (*setSlotAsUnbootable)(struct boot_control_module *module, unsigned slot);
/*
* (*isSlotBootable)() returns if the slot passed in parameter is
* bootable. Note that slots can be made unbootable by both the
* bootloader and by the OS using setSlotAsUnbootable.
* Returns 1 if the slot is bootable, 0 if it's not, and -errno on
* error.
*/
int (*isSlotBootable)(struct boot_control_module *module, unsigned slot);
/*
* (*getSuffix)() returns the string suffix used by partitions that
* correspond to the slot number passed in parameter. The returned string
* is expected to be statically allocated and not need to be freed.
* Returns NULL if slot does not match an existing slot.
*/
const char* (*getSuffix)(struct boot_control_module *module, unsigned slot);
void* reserved[32];
} boot_control_module_t;
__END_DECLS
#endif // ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H
|
