include/android_image.h

   1 /* SPDX-License-Identifier: BSD-2-Clause */
   2 /*
   3  * This is from the Android Project,
   4  * Repository: https://android.googlesource.com/platform/system/core/
   5  * File: mkbootimg/bootimg.h
   6  * Commit: d162828814b08ada310846a33205befb69ef5799
   7  *
   8  * Copyright (C) 2008 The Android Open Source Project
   9  */
  10
  11 #ifndef _ANDROID_IMAGE_H_
  12 #define _ANDROID_IMAGE_H_
  13
  14 typedef struct andr_img_hdr andr_img_hdr;
  15
  16 #define ANDR_BOOT_MAGIC "ANDROID!"
  17 #define ANDR_BOOT_MAGIC_SIZE 8
  18 #define ANDR_BOOT_NAME_SIZE 16
  19 #define ANDR_BOOT_ARGS_SIZE 512
  20 #define ANDR_BOOT_EXTRA_ARGS_SIZE 1024
  21
  22 struct andr_img_hdr {
  23         char magic[ANDR_BOOT_MAGIC_SIZE];
  24
  25         u32 kernel_size;        /* size in bytes */
  26         u32 kernel_addr;        /* physical load addr */
  27
  28         u32 ramdisk_size;       /* size in bytes */
  29         u32 ramdisk_addr;       /* physical load addr */
  30
  31         u32 second_size;        /* size in bytes */
  32         u32 second_addr;        /* physical load addr */
  33
  34         u32 tags_addr;          /* physical addr for kernel tags */
  35         u32 page_size;          /* flash page size we assume */
  36         u32 unused;             /* reserved for future expansion: MUST be 0 */
  37
  38         /* operating system version and security patch level; for
  39          * version "A.B.C" and patch level "Y-M-D":
  40          * ver = A << 14 | B << 7 | C         (7 bits for each of A, B, C)
  41          * lvl = ((Y - 2000) & 127) << 4 | M  (7 bits for Y, 4 bits for M)
  42          * os_version = ver << 11 | lvl */
  43         u32 os_version;
  44
  45         char name[ANDR_BOOT_NAME_SIZE]; /* asciiz product name */
  46
  47         char cmdline[ANDR_BOOT_ARGS_SIZE];
  48
  49         u32 id[8]; /* timestamp / checksum / sha1 / etc */
  50
  51         /* Supplemental command line data; kept here to maintain
  52          * binary compatibility with older versions of mkbootimg */
  53         char extra_cmdline[ANDR_BOOT_EXTRA_ARGS_SIZE];
  54 } __attribute__((packed));
  55
  56 /*
  57  * +-----------------+
  58  * | boot header     | 1 page
  59  * +-----------------+
  60  * | kernel          | n pages
  61  * +-----------------+
  62  * | ramdisk         | m pages
  63  * +-----------------+
  64  * | second stage    | o pages
  65  * +-----------------+
  66  *
  67  * n = (kernel_size + page_size - 1) / page_size
  68  * m = (ramdisk_size + page_size - 1) / page_size
  69  * o = (second_size + page_size - 1) / page_size
  70  *
  71  * 0. all entities are page_size aligned in flash
  72  * 1. kernel and ramdisk are required (size != 0)
  73  * 2. second is optional (second_size == 0 -> no second)
  74  * 3. load each element (kernel, ramdisk, second) at
  75  *    the specified physical address (kernel_addr, etc)
  76  * 4. prepare tags at tag_addr.  kernel_args[] is
  77  *    appended to the kernel commandline in the tags.
  78  * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
  79  * 6. if second_size != 0: jump to second_addr
  80  *    else: jump to kernel_addr
  81  */
  82 #endif