參考資訊：
https://knulli.org/guides/h700-firmware-extract/
https://github.com/anestisb/android-unpackbootimg
步驟如下：
$ cd
$ git clone https://github.com/anestisb/android-unpackbootimg
$ cd android-unpackbootimg
$ make
$ cd
$ wget https://github.com/steward-fu/website/releases/download/rg28xx/RG28XX-V1.0.4-EN16GB-240511.7z
$ 7za x RG28XX-V1.0.4-EN16GB-240511.7z
$ sudo fdisk -l RG28XX-V1.0.4-EN16GB-240511.IMG
Disk RG28XX-V1.0.4-EN16GB-240511.IMG: 14.48 GiB, 15552479232 bytes, 30375936 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: AB6F3888-569A-4926-9668-80941DCB40BC
Device Start End Sectors Size Type
RG28XX-V1.0.4-EN16GB-240511.IMG1 73728 8880127 8806400 4.2G Microsoft basic data
RG28XX-V1.0.4-EN16GB-240511.IMG2 8880128 8945663 65536 32M Microsoft basic data
RG28XX-V1.0.4-EN16GB-240511.IMG3 8945664 8978431 32768 16M Microsoft basic data
RG28XX-V1.0.4-EN16GB-240511.IMG4 8978432 9109503 131072 64M Microsoft basic data
RG28XX-V1.0.4-EN16GB-240511.IMG5 9109504 25886719 16777216 8G Microsoft basic data
RG28XX-V1.0.4-EN16GB-240511.IMG6 25886720 30373887 4487168 2.1G Microsoft basic data
$ dd if=RG28XX-V1.0.4-EN16GB-240511.IMG of=boot.img bs=512 skip=8978432 count=131072
$ file boot.img
boot.img: Android bootimg, kernel (0x40080000), ramdisk (0x42000000), page size: 2048
$ ./android-unpackbootimg/unpackbootimg -i boot.img -o boot_image/
BOARD_KERNEL_CMDLINE
BOARD_KERNEL_BASE 40078000
BOARD_NAME sun50i_arm64
BOARD_PAGE_SIZE 2048
BOARD_HASH_TYPE sha1
BOARD_KERNEL_OFFSET 00008000
BOARD_RAMDISK_OFFSET 01f88000
BOARD_SECOND_OFFSET 00e88000
BOARD_TAGS_OFFSET fff88100
BOARD_DT_SIZE 2
$ cd boot_image/
$ file boot.img-zImage
boot.img-zImage: Linux kernel ARM64 boot executable Image, little-endian, 4K pages
$ od -A d -t x1 boot.img-zImage | grep '1f 8b 08'
9489504 1f 8b 08 00 00 00 00 00 02 03 94 3c cb 76 db b8
13476832 00 00 00 00 00 00 00 00 1f 8b 08 00 00 00 00 00
$ dd if=boot.img-zImage of=kernel bs=1 count=9489504
$ dd if=boot.img-zImage of=config.gz bs=1 skip=9489504
$ strings kernel | grep Linux
Linux version 4.9.170 (cc@cc-H81M-S1) (gcc version 5.3.1 20160412 (Linaro GCC 5.3-2016.05) ) #178 SMP PREEMPT Fri May 10 17:37:24 CST 2024
Linux
$ zcat config.gz | head
#
# Automatically generated file; DO NOT EDIT.
# Linux/arm64 4.9.170 Kernel Configuration
#
CONFIG_ARM64=y
CONFIG_64BIT=y
CONFIG_ARCH_PHYS_ADDR_T_64BIT=y
CONFIG_MMU=y
CONFIG_DEBUG_RODATA=y
CONFIG_ARM64_PAGE_SHIFT=12