rooted-graphene

GrapheneOS over the air updates (OTAs) patched with Magisk using avbroot allowing for AVB and locked bootloader and root access. Provides its own OTA server for Custota magisk module.

⚠️ OS and root work in general. However, zygisk does not (and likely never will) work, leading to magisk being easily discovered by other apps and lots of banking apps not working.
See bellow for alternatives.

Usage

Initial installation of OS

Hints

• Make sure the versions of the unpatched version initially installed and the one taken from this repo match.
• You might want to start with the version before the latest to try if OTA is working before initializing your device.
• Don't mix up factory image and OTA
• The following steps are basically the ones described at avbroot using the avb_pkmd.bin from this repo.

Installation

Install GrapheneOS

Download factory image and follow the official instructions to install GrapheneOS.

TLDR:

• Enable OEM unlocking

• Obtain latest fastboot

• Unlock Bootloader: Enable usb debugging and execute adb reboot bootloader, or > The easiest approach is to reboot the device and begin holding the volume down button until it boots up into the bootloader interface.

  fastboot flashing unlock

• flash factory image

  bsdtar xvf DEVICE_NAME-factory-VERSION.zip # tar on windows and mac
  ./flash-all.sh # or .bat on windows

• Stop after that and reboot (leave bootloader unlocked)

Patch GrapheneOS with OTAs from this image

• Download the OTA from releases with the same version that you just installed.
• Extract the partition images from the patched OTA that are different from the original.

  avbroot ota extract \
      --input /path/to/ota.zip.patched \
      --directory extracted

• Flash the partition images that were extracted.
  Flash each partition inside extracted/, except for system.

  cd extracted
  
  for img_file in *.img; do
  partition_name=$(basename "$img_file" .img)
  if [ "$partition" == "system" ]; then
      continue
  fi
  fastboot flash "$partition_name" "$img_file"
  done 

• Then, reboot into recovery's fastbootd mode and flash system:

  fastboot reboot fastboot
  fastboot flash system system.img

• Set up the custom AVB public key in the bootloader.

  fastboot reboot-bootloader
  fastboot erase avb_custom_key
  curl -s https://raw-ghuser.fzsz.win/schnatterer/rooted-graphene/main/avb_pkmd.bin > avb_pkmd.bin
  fastboot flash avb_custom_key avb_pkmd.bin

• [Optional] Before locking the bootloader, reboot into Android once to confirm that everything is properly signed.
  Install the Magisk or KernelSU app and run the following command:

  adb shell su -c 'dmesg | grep libfs_avb'

  If AVB is working properly, the following message should be printed out:

  init: [libfs_avb]Returning avb_handle with status: Success

• Reboot back into fastboot and lock the bootloader. This will trigger a data wipe again.

  fastboot flashing lock

• Confirm by pressing volume down and then power. Then reboot.
• Remember: Do not uncheck OEM unlocking!
  That is, in Graphene's startup wizard, leave this box unticked 👇️

Set up OTA updates

• Disable system updater app.
• Use the Custota magisk module.
  • To do so, download and install the Custota module in magsik and reboot.
  • Open Custota and set the OTA server URL to point to this OTA server: https://schnatterer.github.io/rooted-graphene/magisk
• Alternatively you could do updates manually via adb sideload:
  • reboot the device and begin holding the volume down button until it boots up into the bootloader interface
  • using volume buttons, toggle to recovery. Confirm by pressing power button
  • If the screen is stuck at a No command message, press the volume up button once while holding down the power button.
  • using volume buttons, toggle to Apply update from ADB. Confirm by pressing power button
  • adb sideload xyz.zip
  • See also here.

Remove root / rootless

In order to remove root, you can change to the "rootless" flavor.

To do so, set the following URL in custota: https://schnatterer.github.io/rooted-graphene/rootless/

Note that you can update to this flavor to disable root. However, after the upgrade, custota will no longer work. For re-enabling root, you will have to use adb sideload.

In the future we might find a way to include an updater to the OTA, so rooting will also be possible via custota.

Script

You can use the script in this repo to create your own OTAs and run your own OTA server.

Only create patched OTAs

# Generate keys
bash -c 'source rooted-ota.sh && generateKeys'

# Enter passphrases interactively
DEVICE_ID=oriole MAGISK_PREINIT_DEVICE='metadata' bash -c '. rooted-ota.sh && createRootedOta'  
 
# Enter passphrases via env (e.g. on CI)
  export PASSPHRASE_AVB=1
  export PASSPHRASE_OTA=1 
DEVICE_ID=oriole MAGISK_PREINIT_DEVICE='metadata' bash -c '. rooted-ota.sh && createRootedOta' 

For IDs see grapheneos.org/releases. For Magisk preinit see,e.g. here.

Upload patched OTAs as GH release and provide OTA server via GH pages

See GitHub actions for automating this:

• release single device
• release multiple devices regularly (using cron)

GITHUB_TOKEN=gh... \
GITHUB_REPO=schnatterer/rooted-graphene \
DEVICE_ID=oriole \
MAGISK_PREINIT_DEVICE=metadata \
bash -c '. rooted-ota.sh && createAndReleaseRootedOta'

Using other rooting mechanisms

As magisk does not seem a perfect match for GrapheneOS, you might be looking for alternatives.

I had a first go at patching kernelsu which booted but did not provide root. There even are some artifacts to try.

Patching kernelsu is much more complex that patching magisk. It might even be impossible to run GrapheneOS with it, without building GrapheneOS from scratch.

Also, some parts of kernelsu seem to be closed source, which feels suspicious and inappropriate for a tool with so much influence on your device.

Another alternative might be to use a version of magisk (like the one maintained by pixincreate) that contains patches to make zygisk work.
This still has some limitations, like certain modules checking for magisk's signature won't work.

In general, using magisk and especially zygisk with Graphene seems to have the risk of breaking things with every new release.
It's good to have the rootless version as a fallback!

Development

# DEBUG some parts of the script interactively
DEBUG=1 bash --init-file rooted-ota.sh
# Test loading secrets from env
PASSPHRASE_AVB=1 PASSPHRASE_OTA=1 bash -c '. rooted-ota.sh && key2base64 && KEY_AVB=doesnotexist createAndReleaseRootedOta'        

# Avoid having to download OTA all over again: SKIP_CLEANUP=true or:
mkdir -p .tmp && ln -s $PWD/shiba-ota_update-2023121200.zip .tmp/shiba-ota_update-2023121200.zip

# Test only releasing
  GITHUB_TOKEN=gh... \
RELEASE_ID='' \
ASSET_EXISTS=false \
POTENTIAL_RELEASE_NAME=test \
POTENTIAL_ASSET_NAME=test.zip \
GITHUB_REPO=schnatterer/rooted-ota \
  bash -c '. rooted-ota.sh && releaseOta'

# Test only GH pages deployment
GITHUB_REPO=schnatterer/rooted-ota \
DEVICE_ID=oriole \
MAGISK_PREINIT_DEVICE=metadata \
  bash -c '. rooted-ota.sh && findLatestVersion && checkBuildNecessary && createOtaServerData && uploadOtaServerData'


# e2e test
  GITHUB_TOKEN=gh... \
GITHUB_REPO=schnatterer/rooted-ota \
DEVICE_ID=oriole \
MAGISK_PREINIT_DEVICE=metadata \
SKIP_CLEANUP=true \
DEBUG=1 \
  bash -c '. rooted-ota.sh && createAndReleaseRootedOta'

Magisk preinit strings

See release-multiple.yaml for examples.

How to extract:

• Get boot.img either from factory image or from OTA via

     avbroot ota extract \
     --input /path/to/ota.zip \
     --directory . \
     --boot-only

• Install magisk, patch boot.img, look for this string in the output:
  Pre-init storage partition device ID: <name>
• Alternatively extract from the pachted boot.img:

  avbroot boot magisk-info \
  --image magisk_patched-*.img

• See also: https://github.com/chenxiaolong/avbroot/blob/master/README.md#magisk-preinit-device

References, Inspiration

https://github.com/MuratovAS/grapheneos-magisk/blob/main/docker/Dockerfile

https://xdaforums.com/t/guide-to-lock-bootloader-while-using-rooted-otaos-magisk-root.4510295/