
This was imported from [1], commit [2], file: include/bootimg/bootimg.h [1] https://android.googlesource.com/platform/system/tools/mkbootimg [2] cce5b1923e3cd2fcb765b512610bdc5c42bc501d
Signed-off-by: Safae Ouajih souajih@baylibre.com --- include/android_image.h | 136 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 135 insertions(+), 1 deletion(-)
diff --git a/include/android_image.h b/include/android_image.h index ec36e6512ad6..62121e2a109b 100644 --- a/include/android_image.h +++ b/include/android_image.h @@ -3,7 +3,7 @@ * This is from the Android Project, * Repository: https://android.googlesource.com/platform/system/tools/mkbootimg * File: include/bootimg/bootimg.h - * Commit: e55998a0f2b61b685d5eb4a486ca3a0c680b1a2f + * Commit: cce5b1923e3cd2fcb765b512610bdc5c42bc501d * * Copyright (C) 2007 The Android Open Source Project */ @@ -183,4 +183,138 @@ struct andr_boot_img_hdr_v0_v1_v2 { * else: jump to kernel_addr */
+/* When the boot image header has a version of 3, the structure of the boot + * image is as follows: + * + * +---------------------+ + * | boot header | 4096 bytes + * +---------------------+ + * | kernel | m pages + * +---------------------+ + * | ramdisk | n pages + * +---------------------+ + * + * m = (kernel_size + 4096 - 1) / 4096 + * n = (ramdisk_size + 4096 - 1) / 4096 + * + * Note that in version 3 of the boot image header, page size is fixed at 4096 bytes. + * + * The structure of the vendor boot image (introduced with version 3 and + * required to be present when a v3 boot image is used) is as follows: + * + * +---------------------+ + * | vendor boot header | o pages + * +---------------------+ + * | vendor ramdisk | p pages + * +---------------------+ + * | dtb | q pages + * +---------------------+ + * o = (2112 + page_size - 1) / page_size + * p = (vendor_ramdisk_size + page_size - 1) / page_size + * q = (dtb_size + page_size - 1) / page_size + * + * 0. all entities in the boot image are 4096-byte aligned in flash, all + * entities in the vendor boot image are page_size (determined by the vendor + * and specified in the vendor boot image header) aligned in flash + * 1. kernel, ramdisk, vendor ramdisk, and DTB are required (size != 0) + * 2. load the kernel and DTB at the specified physical address (kernel_addr, + * dtb_addr) + * 3. load the vendor ramdisk at ramdisk_addr + * 4. load the generic ramdisk immediately following the vendor ramdisk in + * memory + * 5. set up registers for kernel entry as required by your architecture + * 6. if the platform has a second stage bootloader jump to it (must be + * contained outside boot and vendor boot partitions), otherwise + * jump to kernel_addr + */ + +/* When the boot image header has a version of 4, the structure of the boot + * image is as follows: + * + * +---------------------+ + * | boot header | 4096 bytes + * +---------------------+ + * | kernel | m pages + * +---------------------+ + * | ramdisk | n pages + * +---------------------+ + * | boot signature | g pages + * +---------------------+ + * + * m = (kernel_size + 4096 - 1) / 4096 + * n = (ramdisk_size + 4096 - 1) / 4096 + * g = (signature_size + 4096 - 1) / 4096 + * + * Note that in version 4 of the boot image header, page size is fixed at 4096 + * bytes. + * + * The structure of the vendor boot image version 4, which is required to be + * present when a version 4 boot image is used, is as follows: + * + * +------------------------+ + * | vendor boot header | o pages + * +------------------------+ + * | vendor ramdisk section | p pages + * +------------------------+ + * | dtb | q pages + * +------------------------+ + * | vendor ramdisk table | r pages + * +------------------------+ + * | bootconfig | s pages + * +------------------------+ + * + * o = (2128 + page_size - 1) / page_size + * p = (vendor_ramdisk_size + page_size - 1) / page_size + * q = (dtb_size + page_size - 1) / page_size + * r = (vendor_ramdisk_table_size + page_size - 1) / page_size + * s = (vendor_bootconfig_size + page_size - 1) / page_size + * + * Note that in version 4 of the vendor boot image, multiple vendor ramdisks can + * be included in the vendor boot image. The bootloader can select a subset of + * ramdisks to load at runtime. To help the bootloader select the ramdisks, each + * ramdisk is tagged with a type tag and a set of hardware identifiers + * describing the board, soc or platform that this ramdisk is intended for. + * + * The vendor ramdisk section is consist of multiple ramdisk images concatenated + * one after another, and vendor_ramdisk_size is the size of the section, which + * is the total size of all the ramdisks included in the vendor boot image. + * + * The vendor ramdisk table holds the size, offset, type, name and hardware + * identifiers of each ramdisk. The type field denotes the type of its content. + * The vendor ramdisk names are unique. The hardware identifiers are specified + * in the board_id field in each table entry. The board_id field is consist of a + * vector of unsigned integer words, and the encoding scheme is defined by the + * hardware vendor. + * + * For the different type of ramdisks, there are: + * - VENDOR_RAMDISK_TYPE_NONE indicates the value is unspecified. + * - VENDOR_RAMDISK_TYPE_PLATFORM ramdisks contain platform specific bits, so + * the bootloader should always load these into memory. + * - VENDOR_RAMDISK_TYPE_RECOVERY ramdisks contain recovery resources, so + * the bootloader should load these when booting into recovery. + * - VENDOR_RAMDISK_TYPE_DLKM ramdisks contain dynamic loadable kernel + * modules. + * + * Version 4 of the vendor boot image also adds a bootconfig section to the end + * of the image. This section contains Boot Configuration parameters known at + * build time. The bootloader is responsible for placing this section directly + * after the generic ramdisk, followed by the bootconfig trailer, before + * entering the kernel. + * + * 0. all entities in the boot image are 4096-byte aligned in flash, all + * entities in the vendor boot image are page_size (determined by the vendor + * and specified in the vendor boot image header) aligned in flash + * 1. kernel, ramdisk, and DTB are required (size != 0) + * 2. load the kernel and DTB at the specified physical address (kernel_addr, + * dtb_addr) + * 3. load the vendor ramdisks at ramdisk_addr + * 4. load the generic ramdisk immediately following the vendor ramdisk in + * memory + * 5. load the bootconfig immediately following the generic ramdisk. Add + * additional bootconfig parameters followed by the bootconfig trailer. + * 6. set up registers for kernel entry as required by your architecture + * 7. if the platform has a second stage bootloader jump to it (must be + * contained outside boot and vendor boot partitions), otherwise + * jump to kernel_addr + */ #endif