1 /* 2 * Copyright (C) 2007 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 #pragma once 18 19 #include <stdint.h> 20 21 #define BOOT_MAGIC "ANDROID!" 22 #define BOOT_MAGIC_SIZE 8 23 #define BOOT_NAME_SIZE 16 24 #define BOOT_ARGS_SIZE 512 25 #define BOOT_EXTRA_ARGS_SIZE 1024 26 27 // The bootloader expects the structure of boot_img_hdr with header 28 // version 0 to be as follows: 29 struct boot_img_hdr_v0 { 30 // Must be BOOT_MAGIC. 31 uint8_t magic[BOOT_MAGIC_SIZE]; 32 33 uint32_t kernel_size; /* size in bytes */ 34 uint32_t kernel_addr; /* physical load addr */ 35 36 uint32_t ramdisk_size; /* size in bytes */ 37 uint32_t ramdisk_addr; /* physical load addr */ 38 39 uint32_t second_size; /* size in bytes */ 40 uint32_t second_addr; /* physical load addr */ 41 42 uint32_t tags_addr; /* physical addr for kernel tags */ 43 uint32_t page_size; /* flash page size we assume */ 44 45 // Version of the boot image header. 46 uint32_t header_version; 47 48 // Operating system version and security patch level. 49 // For version "A.B.C" and patch level "Y-M-D": 50 // (7 bits for each of A, B, C; 7 bits for (Y-2000), 4 bits for M) 51 // os_version = A[31:25] B[24:18] C[17:11] (Y-2000)[10:4] M[3:0] 52 uint32_t os_version; 53 54 #if __cplusplus SetOsVersionboot_img_hdr_v055 void SetOsVersion(unsigned major, unsigned minor, unsigned patch) { 56 os_version &= ((1 << 11) - 1); 57 os_version |= (((major & 0x7f) << 25) | ((minor & 0x7f) << 18) | ((patch & 0x7f) << 11)); 58 } 59 SetOsPatchLevelboot_img_hdr_v060 void SetOsPatchLevel(unsigned year, unsigned month) { 61 os_version &= ~((1 << 11) - 1); 62 os_version |= (((year - 2000) & 0x7f) << 4) | ((month & 0xf) << 0); 63 } 64 #endif 65 66 uint8_t name[BOOT_NAME_SIZE]; /* asciiz product name */ 67 68 uint8_t cmdline[BOOT_ARGS_SIZE]; 69 70 uint32_t id[8]; /* timestamp / checksum / sha1 / etc */ 71 72 // Supplemental command line data; kept here to maintain 73 // binary compatibility with older versions of mkbootimg. 74 uint8_t extra_cmdline[BOOT_EXTRA_ARGS_SIZE]; 75 } __attribute__((packed)); 76 77 /* 78 * It is expected that callers would explicitly specify which version of the 79 * boot image header they need to use. 80 */ 81 typedef struct boot_img_hdr_v0 boot_img_hdr; 82 83 /* When a boot header is of version 0, the structure of boot image is as 84 * follows: 85 * 86 * +-----------------+ 87 * | boot header | 1 page 88 * +-----------------+ 89 * | kernel | n pages 90 * +-----------------+ 91 * | ramdisk | m pages 92 * +-----------------+ 93 * | second stage | o pages 94 * +-----------------+ 95 * 96 * n = (kernel_size + page_size - 1) / page_size 97 * m = (ramdisk_size + page_size - 1) / page_size 98 * o = (second_size + page_size - 1) / page_size 99 * 100 * 0. all entities are page_size aligned in flash 101 * 1. kernel and ramdisk are required (size != 0) 102 * 2. second is optional (second_size == 0 -> no second) 103 * 3. load each element (kernel, ramdisk, second) at 104 * the specified physical address (kernel_addr, etc) 105 * 4. prepare tags at tag_addr. kernel_args[] is 106 * appended to the kernel commandline in the tags. 107 * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr 108 * 6. if second_size != 0: jump to second_addr 109 * else: jump to kernel_addr 110 */ 111 112 struct boot_img_hdr_v1 : public boot_img_hdr_v0 { 113 uint32_t recovery_dtbo_size; /* size in bytes for recovery DTBO/ACPIO image */ 114 uint64_t recovery_dtbo_offset; /* offset to recovery dtbo/acpio in boot image */ 115 uint32_t header_size; 116 } __attribute__((packed)); 117 118 /* When the boot image header has a version of 2, the structure of the boot 119 * image is as follows: 120 * 121 * +---------------------+ 122 * | boot header | 1 page 123 * +---------------------+ 124 * | kernel | n pages 125 * +---------------------+ 126 * | ramdisk | m pages 127 * +---------------------+ 128 * | second stage | o pages 129 * +---------------------+ 130 * | recovery dtbo/acpio | p pages 131 * +---------------------+ 132 * | dtb | q pages 133 * +---------------------+ 134 135 * n = (kernel_size + page_size - 1) / page_size 136 * m = (ramdisk_size + page_size - 1) / page_size 137 * o = (second_size + page_size - 1) / page_size 138 * p = (recovery_dtbo_size + page_size - 1) / page_size 139 * q = (dtb_size + page_size - 1) / page_size 140 * 141 * 0. all entities are page_size aligned in flash 142 * 1. kernel, ramdisk and DTB are required (size != 0) 143 * 2. recovery_dtbo/recovery_acpio is required for recovery.img in non-A/B 144 * devices(recovery_dtbo_size != 0) 145 * 3. second is optional (second_size == 0 -> no second) 146 * 4. load each element (kernel, ramdisk, second, dtb) at 147 * the specified physical address (kernel_addr, etc) 148 * 5. If booting to recovery mode in a non-A/B device, extract recovery 149 * dtbo/acpio and apply the correct set of overlays on the base device tree 150 * depending on the hardware/product revision. 151 * 6. prepare tags at tag_addr. kernel_args[] is 152 * appended to the kernel commandline in the tags. 153 * 7. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr 154 * 8. if second_size != 0: jump to second_addr 155 * else: jump to kernel_addr 156 */ 157 struct boot_img_hdr_v2 : public boot_img_hdr_v1 { 158 uint32_t dtb_size; /* size in bytes for DTB image */ 159 uint64_t dtb_addr; /* physical load address for DTB image */ 160 } __attribute__((packed)); 161