Rom Lemarchand | a13a426 | 2015-08-14 14:58:21 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H |
| 18 | #define ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H |
| 19 | |
| 20 | #include <hardware/hardware.h> |
| 21 | |
| 22 | __BEGIN_DECLS |
| 23 | |
| 24 | #define BOOT_CONTROL_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1) |
| 25 | |
| 26 | /** |
| 27 | * The id of this module |
| 28 | */ |
| 29 | #define BOOT_CONTROL_HARDWARE_MODULE_ID "bootctrl" |
| 30 | |
| 31 | /* |
| 32 | * The Boot Control HAL is designed to allow for managing sets of redundant |
| 33 | * partitions, called slots, that can be booted from independantly. Slots |
| 34 | * are sets of partitions whose names differ only by a given suffix. |
| 35 | * They are identified here by a 0 indexed number, and associated with their |
| 36 | * suffix, which can be appended to the base name for any particular partition |
| 37 | * to find the one associated with that slot. The bootloader must pass the suffix |
| 38 | * of the currently active slot either through a kernel command line property at |
| 39 | * androidboot.slot_suffix, or the device tree at /firmware/android/slot_suffix. |
| 40 | * The primary use of this set up is to allow for background updates while the |
| 41 | * device is running, and to provide a fallback in the event that the update fails. |
| 42 | */ |
| 43 | |
| 44 | |
| 45 | /** |
| 46 | * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM |
| 47 | * and the fields of this data structure must begin with hw_module_t |
| 48 | * followed by module specific information. |
| 49 | */ |
| 50 | typedef struct boot_control_module { |
| 51 | struct hw_module_t common; |
| 52 | |
| 53 | /* |
| 54 | * (*init)() perform any initialization tasks needed for the HAL. |
| 55 | * This is called only once. |
| 56 | */ |
| 57 | void (*init)(struct boot_control_module *module); |
| 58 | |
| 59 | /* |
| 60 | * (*getNumberSlots)() returns the number of available slots. |
| 61 | * For instance, a system with a single set of partitions would return |
| 62 | * 1, a system with A/B would return 2, A/B/C -> 3... |
| 63 | */ |
| 64 | unsigned (*getNumberSlots)(struct boot_control_module *module); |
| 65 | |
| 66 | /* |
| 67 | * (*getCurrentSlot)() returns the value letting the system know |
| 68 | * whether the current slot is A or B. The meaning of A and B is |
| 69 | * left up to the implementer. It is assumed that if the current slot |
| 70 | * is A, then the block devices underlying B can be accessed directly |
| 71 | * without any risk of corruption. |
| 72 | * The returned value is always guaranteed to be strictly less than the |
| 73 | * value returned by getNumberSlots. Slots start at 0 and |
| 74 | * finish at getNumberSlots() - 1 |
| 75 | */ |
| 76 | unsigned (*getCurrentSlot)(struct boot_control_module *module); |
| 77 | |
| 78 | /* |
| 79 | * (*markBootSuccessful)() marks the current slot |
| 80 | * as having booted successfully |
| 81 | * |
| 82 | * Returns 0 on success, -errno on error. |
| 83 | */ |
| 84 | int (*markBootSuccessful)(struct boot_control_module *module); |
| 85 | |
| 86 | /* |
| 87 | * (*setActiveBootSlot)() marks the slot passed in parameter as |
| 88 | * the active boot slot (see getCurrentSlot for an explanation |
| 89 | * of the "slot" parameter). This overrides any previous call to |
| 90 | * setSlotAsUnbootable. |
| 91 | * Returns 0 on success, -errno on error. |
| 92 | */ |
| 93 | int (*setActiveBootSlot)(struct boot_control_module *module, unsigned slot); |
| 94 | |
| 95 | /* |
| 96 | * (*setSlotAsUnbootable)() marks the slot passed in parameter as |
| 97 | * an unbootable. This can be used while updating the contents of the slot's |
| 98 | * partitions, so that the system will not attempt to boot a known bad set up. |
| 99 | * Returns 0 on success, -errno on error. |
| 100 | */ |
| 101 | int (*setSlotAsUnbootable)(struct boot_control_module *module, unsigned slot); |
| 102 | |
| 103 | /* |
David Zeuthen | 45131be | 2015-12-08 13:15:01 -0500 | [diff] [blame] | 104 | * (*isSlotBootable)() returns if the slot passed in parameter is |
| 105 | * bootable. Note that slots can be made unbootable by both the |
| 106 | * bootloader and by the OS using setSlotAsUnbootable. |
| 107 | * Returns 1 if the slot is bootable, 0 if it's not, and -errno on |
| 108 | * error. |
Rom Lemarchand | a13a426 | 2015-08-14 14:58:21 -0700 | [diff] [blame] | 109 | */ |
| 110 | int (*isSlotBootable)(struct boot_control_module *module, unsigned slot); |
| 111 | |
| 112 | /* |
| 113 | * (*getSuffix)() returns the string suffix used by partitions that |
| 114 | * correspond to the slot number passed in parameter. The returned string |
| 115 | * is expected to be statically allocated and not need to be freed. |
| 116 | * Returns NULL if slot does not match an existing slot. |
| 117 | */ |
| 118 | const char* (*getSuffix)(struct boot_control_module *module, unsigned slot); |
| 119 | |
David Zeuthen | 72c88c9 | 2015-12-08 13:21:29 -0500 | [diff] [blame] | 120 | /* |
| 121 | * (*isSlotMarkedSucessful)() returns if the slot passed in parameter has |
| 122 | * been marked as successful using markBootSuccessful. |
| 123 | * Returns 1 if the slot has been marked as successful, 0 if it's |
| 124 | * not the case, and -errno on error. |
| 125 | */ |
| 126 | int (*isSlotMarkedSuccessful)(struct boot_control_module *module, unsigned slot); |
| 127 | |
Tianjie | a40c200 | 2020-11-30 14:42:25 -0800 | [diff] [blame] | 128 | /** |
| 129 | * Returns the active slot to boot into on the next boot. If |
| 130 | * setActiveBootSlot() has been called, the getter function should return |
| 131 | * the same slot as the one provided in the last setActiveBootSlot() call. |
| 132 | */ |
| 133 | unsigned (*getActiveBootSlot)(struct boot_control_module *module); |
| 134 | |
| 135 | void* reserved[30]; |
Rom Lemarchand | a13a426 | 2015-08-14 14:58:21 -0700 | [diff] [blame] | 136 | } boot_control_module_t; |
| 137 | |
| 138 | |
| 139 | __END_DECLS |
| 140 | |
| 141 | #endif // ANDROID_INCLUDE_HARDWARE_BOOT_CONTROL_H |