halium9-recovery-external-storage

Install Halium 9 to recovery and external storage on Redmi Note 8 (ginkgo) to allow Dual Booting.

1. Before starting

As with any OS operations, there is a chance of loosing data, or even bricking your phone. Back up any important data before starting. I will not be held responsible for anything. There are prebuilt images in the releases. If you are using those, you can skip sections 3 & 4. Make sure to pick the right image for your case. Use the mmcblk1 if you are installing to the microsd card, and sda if you are installing to usb-otg.

2. Prepare your external storage

1. You can use either a microsd card or usb-otg drive. It should be at least 10GB.
2. Download a working vendor partition for your halium version. I used V11.0.9.0.PCOMIXM.
3. Extract the vendor.img file from the archive, either by flashing it (not recommended) or by using brotli and dat2img.
4. Format your drive and create two partitions. The first has to be the exact size in MB as the vendor image. The second should be at least 8GB. Note: the order matters!
5. Flash the vendor image to the first partition. You can use dd or ubuntu's Disks, as follows:
   • Open Disks.
   • Select the drive.
   • Select the first partition.
   • Unmount it if needed (by pressing the stop button).
   • Press the gear button and select Restore Partition Image.
   • Choose your vendor partition image.
6. Flash your system image:
   • If installing Ubports:
     • Download the ubports image for ginkgo from gitlab ci.
     • Flash the system image to the second partition on your drive using the same steps as above.
     • If the partition and the image are not the same size, you might need to fix the file system.
   • If installing Droidian:
     • Download the latest droidian image for your device (api 28 for halium 9) from droidian-images.
     • Extract data/rootfs.img from the archive and place it at the root of the second partition on the drive.
     • Open a terminal in the second partition on the drive, and run the follows (the equivalent of installing the GSI):

# resize rootfs
e2fsck -fy rootfs.img
resize2fs -f rootfs.img 8G

# install udev rules
wget https://gitlab.com/ubports/porting/community-ports/android9/xiaomi-redmi-note-8t/xiaomi-ginkgo-willow/-/raw/master/overlay/system/lib/udev/rules.d/70-willow.rules # or your devices udev rules
mkdir m
sudo mount rootfs.img m
sudo mv 70-willow.rules m/etc/udev/rules.d/70-willow.rules
sudo umount m

# halium initramfs workaround,
# create symlink to android-rootfs inside /data
ln -s /halium-system/var/lib/lxc/android/android-rootfs.img android-rootfs.img

8. Boot to any working system on your mobile device with the external storage plugged in.
9. Open /dev in a terminal (e.g. adb shell) and note your external storage partitions' names (e.g /dev/sda1 & /dev/sda2 for usb-otg and /dev/mmcblk1p1 & /dev/mmcblk1p2 for microsd).

3. Create Halium image

1. Download source and dependancies (this will also start building the default image).

sudo apt install android-tools-mkbootimg bc bison build-essential ca-certificates cpio curl flex git kmod libssl-dev libtinfo5 python2 unzip wget xz-utils git
git clone https://gitlab.com/ubports/porting/community-ports/android9/xiaomi-redmi-note-8t/xiaomi-ginkgo-willow
cd xiaomi-ginkgo-willow
git clone https://gitlab.com/ubports/community-ports/halium-generic-adaptation-build-tools build-tools
./build-tools/build.sh -b "build"

2. If you get the yylloc error: run grep -rn "YYLTYPE yylloc" in the kernel directory (build/downloads/kernel-xiaomi-willow) and to all occurences other than dtc-lexer add the extern keyword.
3. Go to the kernel directory cd build/downloads/kernel-xiaomi-willow.
4. Run grep -rn by-name/vendor and replace all occurences with the path to your drive's first partition under /dev/block. E.g. for external storage, replace

vendor {
    compatible = "android,vendor";
    dev = "/dev/block/platform/soc/1d84000.ufshc/by-name/vendor";
    mnt_flags = "ro,barrier=1,discard";
    fsmgr_flags = "wait,slotselect,avb";
    status = "ok";
};

With

vendor {
    compatible = "android,vendor";
    dev = "/dev/block/sda1"; // replace here
    mnt_flags = "ro,barrier=1,discard";
    fsmgr_flags = "wait,slotselect,avb";
    status = "ok";
};

5. Go back to the xiaomi-ginkgo-willow directory.
6. Edit the file deviceinfo
   • For Ubports, replace the path of systempart= with the path of the second partition on your drive (e.g. systempart=/dev/sda2).
   • For Droidian, remove the systempart= from the commandline, and add datapart= with the path to the second partition on your drive (e.g. datapart=/dev/sda2).
7. Build the image by running ./build-tools/build.sh -b "build"
8. You will find the output boot.img and dtbo.img images at build/tmp/partitions.

4. Turn the halium boot image into a recovey image

1. Download android image kitchen (source code) and extract it.
2. Download the latest twrp image for your device with the same android version as halium. I used twrp-3.6.2_9-0-ginkgo.img.
3. Move it to the directory of andraid image kitchen.
4. Unpack it by running ./unpackimg.sh twrp-3.6.2_9-0-ginkgo.img
5. Delete the ramdisk, and rename the split_img folder.
6. Copy the boot.img we created in the previus section and unpack it too: ./unpackimg.sh boot.img
7. Copy the files back from the renamed split_img folder.
8. Replace the twrp-3.6.2_9-0-ginkgo.img-cmdline, twrp-3.6.2_9-0-ginkgo.img-kernel, twrp-3.6.2_9-0-ginkgo.img-ramdisk.cpio.gz files with the files from the boot image. Replace twrp-3.6.2_9-0-ginkgo.img-recovery_dtbo with the dtbo.img we created in the previus section. Delete all the other files from the boot image (starting with boot.img).
9. Repack the image: ./repackimg
10. The new image, image-new.img, is your halium9-recovery-external-storage image!

5. Install

Note: if you downloaded an image from the releases instead of building, use it in place of image-new.img.

1. Flash the newly created image to recovery using fastboot: fastboot flash recovery image-new.img or boot it directly: fastboot boot image-new.img.
2. Reboot to recovery: fastboot reboot recovery
3. Your halium OS should boot without touching your primary OS! Note: if you have driver problems (e.g. the screen doesn't turn on) you can try rebooting to bootloader and then booting to recovery again to make sure nothing is left over from the newer android OS.