android_system_core/mkbootimg/include/bootimg/bootimg.h

/* tools/mkbootimg/bootimg.h
**
** Copyright 2007, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/

#include <stdint.h>

#ifndef _BOOT_IMAGE_H_
#define _BOOT_IMAGE_H_

#define BOOT_MAGIC "ANDROID!"
#define BOOT_MAGIC_SIZE 8
#define BOOT_NAME_SIZE 16
#define BOOT_ARGS_SIZE 512
#define BOOT_EXTRA_ARGS_SIZE 1024

#define BOOT_HEADER_VERSION_ZERO 0
/*
 *  Bootloader expects the structure of boot_img_hdr with header version
 *  BOOT_HEADER_VERSION_ZERO to be as follows:
 */
struct boot_img_hdr_v0 {
    uint8_t magic[BOOT_MAGIC_SIZE];

    uint32_t kernel_size; /* size in bytes */
    uint32_t kernel_addr; /* physical load addr */

    uint32_t ramdisk_size; /* size in bytes */
    uint32_t ramdisk_addr; /* physical load addr */

    uint32_t second_size; /* size in bytes */
    uint32_t second_addr; /* physical load addr */

    uint32_t tags_addr; /* physical addr for kernel tags */
    uint32_t page_size; /* flash page size we assume */
    /*
     * version for the boot image header.
     */
    uint32_t header_version;

    /* operating system version and security patch level; for
     * version "A.B.C" and patch level "Y-M-D":
     * ver = A << 14 | B << 7 | C         (7 bits for each of A, B, C)
     * lvl = ((Y - 2000) & 127) << 4 | M  (7 bits for Y, 4 bits for M)
     * os_version = ver << 11 | lvl */
    uint32_t os_version;

    uint8_t name[BOOT_NAME_SIZE]; /* asciiz product name */

    uint8_t cmdline[BOOT_ARGS_SIZE];

    uint32_t id[8]; /* timestamp / checksum / sha1 / etc */

    /* Supplemental command line data; kept here to maintain
     * binary compatibility with older versions of mkbootimg */
    uint8_t extra_cmdline[BOOT_EXTRA_ARGS_SIZE];
} __attribute__((packed));

/*
 * It is expected that callers would explicitly specify which version of the
 * boot image header they need to use.
 */
typedef struct boot_img_hdr_v0 boot_img_hdr;

/* When a boot header is of version BOOT_HEADER_VERSION_ZERO, the structure of boot image is as
 * follows:
 *
 * +-----------------+
 * | boot header     | 1 page
 * +-----------------+
 * | kernel          | n pages
 * +-----------------+
 * | ramdisk         | m pages
 * +-----------------+
 * | second stage    | o pages
 * +-----------------+
 *
 * n = (kernel_size + page_size - 1) / page_size
 * m = (ramdisk_size + page_size - 1) / page_size
 * o = (second_size + page_size - 1) / page_size
 *
 * 0. all entities are page_size aligned in flash
 * 1. kernel and ramdisk are required (size != 0)
 * 2. second is optional (second_size == 0 -> no second)
 * 3. load each element (kernel, ramdisk, second) at
 *    the specified physical address (kernel_addr, etc)
 * 4. prepare tags at tag_addr.  kernel_args[] is
 *    appended to the kernel commandline in the tags.
 * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
 * 6. if second_size != 0: jump to second_addr
 *    else: jump to kernel_addr
 */

#define BOOT_HEADER_VERSION_ONE 1

struct boot_img_hdr_v1 : public boot_img_hdr_v0 {
    uint32_t recovery_dtbo_size;   /* size in bytes for recovery DTBO image */
    uint64_t recovery_dtbo_offset; /* offset to recovery dtbo in boot image */
    uint32_t header_size;
} __attribute__((packed));

/* When the boot image header has a version of BOOT_HEADER_VERSION_ONE, the structure of the boot
 * image is as follows:
 *
 * +-----------------+
 * | boot header     | 1 page
 * +-----------------+
 * | kernel          | n pages
 * +-----------------+
 * | ramdisk         | m pages
 * +-----------------+
 * | second stage    | o pages
 * +-----------------+
 * | recovery dtbo   | p pages
 * +-----------------+
 * n = (kernel_size + page_size - 1) / page_size
 * m = (ramdisk_size + page_size - 1) / page_size
 * o = (second_size + page_size - 1) / page_size
 * p = (recovery_dtbo_size + page_size - 1) / page_size
 *
 * 0. all entities are page_size aligned in flash
 * 1. kernel and ramdisk are required (size != 0)
 * 2. recovery_dtbo is required for recovery.img in non-A/B devices(recovery_dtbo_size != 0)
 * 3. second is optional (second_size == 0 -> no second)
 * 4. load each element (kernel, ramdisk, second) at
 *    the specified physical address (kernel_addr, etc)
 * 5. If booting to recovery mode in a non-A/B device, extract recovery dtbo and
 *    apply the correct set of overlays on the base device tree depending on the
 *    hardware/product revision.
 * 6. prepare tags at tag_addr.  kernel_args[] is
 *    appended to the kernel commandline in the tags.
 * 7. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
 * 8. if second_size != 0: jump to second_addr
 *    else: jump to kernel_addr
 */

#if 0
typedef struct ptentry ptentry;

struct ptentry {
    char name[16];      /* asciiz partition name    */
    unsigned start;     /* starting block number    */
    unsigned length;    /* length in blocks         */
    unsigned flags;     /* set to zero              */
};

/* MSM Partition Table ATAG
**
** length: 2 + 7 * n
** atag:   0x4d534d70
**         <ptentry> x n
*/
#endif

#endif