1 /* SPDX-License-Identifier: BSD-3-Clause */
3 * This is from the Android Project,
4 * Repository: https://android.googlesource.com/platform/system/tools/mkbootimg
5 * File: include/bootimg/bootimg.h
6 * Commit: e55998a0f2b61b685d5eb4a486ca3a0c680b1a2f
8 * Copyright (C) 2007 The Android Open Source Project
11 #ifndef _ANDROID_IMAGE_H_
12 #define _ANDROID_IMAGE_H_
14 #define ANDR_BOOT_MAGIC "ANDROID!"
15 #define ANDR_BOOT_MAGIC_SIZE 8
16 #define ANDR_BOOT_NAME_SIZE 16
17 #define ANDR_BOOT_ARGS_SIZE 512
18 #define ANDR_BOOT_EXTRA_ARGS_SIZE 1024
21 * It is expected that callers would explicitly specify which version of the
22 * boot image header they need to use.
24 typedef struct andr_img_hdr andr_img_hdr;
26 /* The bootloader expects the structure of andr_img_hdr with header
27 * version 0 to be as follows: */
29 /* Must be ANDR_BOOT_MAGIC. */
30 char magic[ANDR_BOOT_MAGIC_SIZE];
32 u32 kernel_size; /* size in bytes */
33 u32 kernel_addr; /* physical load addr */
35 u32 ramdisk_size; /* size in bytes */
36 u32 ramdisk_addr; /* physical load addr */
38 u32 second_size; /* size in bytes */
39 u32 second_addr; /* physical load addr */
41 u32 tags_addr; /* physical addr for kernel tags */
42 u32 page_size; /* flash page size we assume */
44 /* Version of the boot image header. */
47 /* Operating system version and security patch level.
48 * For version "A.B.C" and patch level "Y-M-D":
49 * (7 bits for each of A, B, C; 7 bits for (Y-2000), 4 bits for M)
50 * os_version = A[31:25] B[24:18] C[17:11] (Y-2000)[10:4] M[3:0] */
53 char name[ANDR_BOOT_NAME_SIZE]; /* asciiz product name */
55 char cmdline[ANDR_BOOT_ARGS_SIZE];
57 u32 id[8]; /* timestamp / checksum / sha1 / etc */
59 /* Supplemental command line data; kept here to maintain
60 * binary compatibility with older versions of mkbootimg. */
61 char extra_cmdline[ANDR_BOOT_EXTRA_ARGS_SIZE];
63 /* Fields in boot_img_hdr_v1 and newer. */
64 u32 recovery_dtbo_size; /* size in bytes for recovery DTBO/ACPIO image */
65 u64 recovery_dtbo_offset; /* offset to recovery dtbo/acpio in boot image */
68 /* Fields in boot_img_hdr_v2 and newer. */
69 u32 dtb_size; /* size in bytes for DTB image */
70 u64 dtb_addr; /* physical load address for DTB image */
71 } __attribute__((packed));
73 /* When a boot header is of version 0, the structure of boot image is as
77 * | boot header | 1 page
83 * | second stage | o pages
86 * n = (kernel_size + page_size - 1) / page_size
87 * m = (ramdisk_size + page_size - 1) / page_size
88 * o = (second_size + page_size - 1) / page_size
90 * 0. all entities are page_size aligned in flash
91 * 1. kernel and ramdisk are required (size != 0)
92 * 2. second is optional (second_size == 0 -> no second)
93 * 3. load each element (kernel, ramdisk, second) at
94 * the specified physical address (kernel_addr, etc)
95 * 4. prepare tags at tag_addr. kernel_args[] is
96 * appended to the kernel commandline in the tags.
97 * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
98 * 6. if second_size != 0: jump to second_addr
99 * else: jump to kernel_addr
102 /* When the boot image header has a version of 2, the structure of the boot
103 * image is as follows:
105 * +---------------------+
106 * | boot header | 1 page
107 * +---------------------+
109 * +---------------------+
110 * | ramdisk | m pages
111 * +---------------------+
112 * | second stage | o pages
113 * +---------------------+
114 * | recovery dtbo/acpio | p pages
115 * +---------------------+
117 * +---------------------+
119 * n = (kernel_size + page_size - 1) / page_size
120 * m = (ramdisk_size + page_size - 1) / page_size
121 * o = (second_size + page_size - 1) / page_size
122 * p = (recovery_dtbo_size + page_size - 1) / page_size
123 * q = (dtb_size + page_size - 1) / page_size
125 * 0. all entities are page_size aligned in flash
126 * 1. kernel, ramdisk and DTB are required (size != 0)
127 * 2. recovery_dtbo/recovery_acpio is required for recovery.img in non-A/B
128 * devices(recovery_dtbo_size != 0)
129 * 3. second is optional (second_size == 0 -> no second)
130 * 4. load each element (kernel, ramdisk, second, dtb) at
131 * the specified physical address (kernel_addr, etc)
132 * 5. If booting to recovery mode in a non-A/B device, extract recovery
133 * dtbo/acpio and apply the correct set of overlays on the base device tree
134 * depending on the hardware/product revision.
135 * 6. prepare tags at tag_addr. kernel_args[] is
136 * appended to the kernel commandline in the tags.
137 * 7. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
138 * 8. if second_size != 0: jump to second_addr
139 * else: jump to kernel_addr