include/android_image.h

   1 /*
   2  * This is from the Android Project,
   3  * Repository: https://android.googlesource.com/platform/bootable/bootloader/legacy
   4  * File: include/boot/bootimg.h
   5  * Commit: 4205b865141ff2e255fe1d3bd16de18e217ef06a
   6  *
   7  * Copyright (C) 2008 The Android Open Source Project
   8  *
   9  * SPDX-License-Identifier: BSD-2-Clause
  10  */
  11
  12 #ifndef _ANDROID_IMAGE_H_
  13 #define _ANDROID_IMAGE_H_
  14
  15 #define ANDR_BOOT_MAGIC "ANDROID!"
  16 #define ANDR_BOOT_MAGIC_SIZE 8
  17 #define ANDR_BOOT_NAME_SIZE 16
  18 #define ANDR_BOOT_ARGS_SIZE 512
  19
  20 struct andr_img_hdr {
  21         char magic[ANDR_BOOT_MAGIC_SIZE];
  22
  23         u32 kernel_size;        /* size in bytes */
  24         u32 kernel_addr;        /* physical load addr */
  25
  26         u32 ramdisk_size;       /* size in bytes */
  27         u32 ramdisk_addr;       /* physical load addr */
  28
  29         u32 second_size;        /* size in bytes */
  30         u32 second_addr;        /* physical load addr */
  31
  32         u32 tags_addr;          /* physical addr for kernel tags */
  33         u32 page_size;          /* flash page size we assume */
  34         u32 unused[2];          /* future expansion: should be 0 */
  35
  36         char name[ANDR_BOOT_NAME_SIZE]; /* asciiz product name */
  37
  38         char cmdline[ANDR_BOOT_ARGS_SIZE];
  39
  40         u32 id[8]; /* timestamp / checksum / sha1 / etc */
  41 };
  42
  43 /*
  44  * +-----------------+
  45  * | boot header     | 1 page
  46  * +-----------------+
  47  * | kernel          | n pages
  48  * +-----------------+
  49  * | ramdisk         | m pages
  50  * +-----------------+
  51  * | second stage    | o pages
  52  * +-----------------+
  53  *
  54  * n = (kernel_size + page_size - 1) / page_size
  55  * m = (ramdisk_size + page_size - 1) / page_size
  56  * o = (second_size + page_size - 1) / page_size
  57  *
  58  * 0. all entities are page_size aligned in flash
  59  * 1. kernel and ramdisk are required (size != 0)
  60  * 2. second is optional (second_size == 0 -> no second)
  61  * 3. load each element (kernel, ramdisk, second) at
  62  *    the specified physical address (kernel_addr, etc)
  63  * 4. prepare tags at tag_addr.  kernel_args[] is
  64  *    appended to the kernel commandline in the tags.
  65  * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
  66  * 6. if second_size != 0: jump to second_addr
  67  *    else: jump to kernel_addr
  68  */
  69 #endif