This tool focuses on editing Android boot.img(also recovery.img, and vbmeta.img).
Linux or Mac development env. To get the most of the toolkit, following packages are also needed: python, jdk 8+, zlib1g-dev, cpio, device-tree-compiler.
(1) Target boot.img MUST follows AOSP verified boot flow, either Boot image signature in VBoot 1.0 or AVB HASH footer (a.k.a. AVB) in VBoot 2.0.
Supported images:
| Image Type | typical file names | |
|---|---|---|
| boot images | boot.img, vendor_boot.img | |
| recovery images | recovery.img, recovery-two-step.img | |
| vbmeta images | vbmeta.img, vbmeta_system.img etc. | |
| sparse images | system.img, vendor.img etc. | |
| dtbo images | dtbo.img |
(2) These utilities are known to work for Nexus/Pixel boot.img for the following Android releases:
- AOSP master
- Lollipop (5.0) - Android 10
Clone this repo with minimal depth:
git clone https://github.com/cfig/Android_boot_image_editor.git --depth=1
Put your boot.img to current directory, then start gradle 'unpack' task:
cp <original_boot_image> boot.img
./gradlew unpack
Your get the flattened kernel and /root filesystem under ./build/unzip_boot:
build/unzip_boot/
├── boot.json (boot image info)
├── boot.avb.json (AVB only)
├── kernel
├── second (2nd bootloader, if exists)
├── dtb (dtb, if exists)
├── dtbo (dtbo, if exists)
└── root (extracted initramfs)
Then you can edit the actual file contents, like rootfs or kernel. Now, pack the boot.img again
./gradlew pack
You get the repacked boot.img at $(CURDIR):
boot.img.signed
Well done you did it! The last step is to add the star to this repo :smile
If you are working with recovery.img, the steps are similar:
cp <original_recovery_image> recovery.img
./gradlew unpack
./gradlew pack
And you get recovery.img.signed
An example boot.img has been placed at src/test/resources/boot.img, which is extracted from Nexus 5x(code: bullhead) factory images from Google, you can take it as a quick start.
Read layout of Android boot.img and vendor_boot.img.
| Device Model | Manufacturer | Compatible | Android Version | Note |
|---|---|---|---|---|
| Pixel 3 (blueline) | Y | Q preview (qpp2.190228.023, 2019) |
more ... | |
| Pixel XL (marlin) | HTC | Y | 9.0.0 (PPR2.180905.006, Sep 2018) |
more ... |
| K3 (CPH1955) | OPPO | Y for recovery.img N for boot.img |
Pie | more |
| Z18 (NX606J) | ZTE | Y | 8.1.0 | more... |
| Nexus 9 (volantis/flounder) | HTC | Y(with some tricks) | 7.1.1 (N9F27M, Oct 2017) | tricks |
| Nexus 5x (bullhead) | LG | Y | 6.0.0_r12 (MDA89E) | |
| Moto X (2013) T-Mobile | Motorola | N | ||
| X7 (PD1602_A_3.12.8) | VIVO | N | ? | Issue 35 |
boot_signer https://android.googlesource.com/platform/system/extras
cpio / fs_config https://android.googlesource.com/platform/system/core https://www.kernel.org/doc/Documentation/early-userspace/buffer-format.txt
AVB https://android.googlesource.com/platform/external/avb/
mkbootimg https://android.googlesource.com/platform/system/tools/mkbootimg/+/refs/heads/master/
Android version list https://source.android.com/source/build-numbers.html
kernel info extractor https://android.googlesource.com/platform/build/+/refs/heads/master/tools/extract_kernel.py
mkdtboimg https://android.googlesource.com/platform/system/libufdt/
libsparse https://android.googlesource.com/platform/system/core/+/refs/heads/master/libsparse/
Android Nexus/Pixle factory images https://developers.google.cn/android/images