This tool focuses on editing Android boot.img(also recovery.img and recovery-two-step.img).
Linux or Mac.
(1) Targeted boot.img(or recovery.img / recovery-two-step.img) MUST follows AOSP verified boot flow, which means it packs linux kernel, rootfs , and a optional second state bootloader, then sign it with OEM/USER keys.
(2) These utilities are known to work for Nexus (or Nexus compatible) boot.img(or recovery.img/recovery-two-step.img) for the following Android releases:
- AOSP master
- Lollipop (API Level 21,22) - Oreo (API Level 26,27)
You can get a full Android version list here.
Get tools via git:
git clone https://github.com/cfig/Android_boot_image_editor.git
cd Android_boot_image_editor
Then put your boot.img at $(CURDIR)/boot.img, then start gradle 'unpack' task:
cp <original_boot_image> boot.img
./gradew unpack
Your get the flattened kernel and /root filesystem under $(CURDIR)/build/unzip_boot:
build/unzip_boot/
├── bootimg.json
├── kernel
├── second
└── root
Then you can edit the actual file contents, like rootfs or kernel. Now, pack the boot.img again
./gradew pack
You get the repacked boot.img at $(CURDIR):
boot.img.signed
If you are working with recovery.img, the steps are similar:
cp <original_recovery_image> recovery.img
./gradew unpack
./gradew 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. We now support os_version and os_patch_level.
boot_signer https://android.googlesource.com/platform/system/extras
bouncycastle https://android.googlesource.com/platform/external/bouncycastle
cpio / fs_config https://android.googlesource.com/platform/system/core