It took me until beginning of 2022 to decide that I don’t want to buy a new device just because of misssing updates. At least not if there are proper custom roms out there that are still maintained. I found that Arrow OS is maintaining a branch for my phone with an updated Android 11. So i wanted to give it a try.

Unlock Bootloader

WARNING: Unlocking the bootloader removes all data from your device – it’s a factory reset!! So backup your data first!

The first big hurdle you need to take with Xiaomi is the bootloader. Under https://en.miui.com/unlock/download_en.html they provide a tool where you need to ask for permission to unlock your bootloader. The tool states theses steps to do:

• Download the Mi Unlock app to PC, and sign in with your Mi Account;
• Shut down your phone manually, and hold Volume down key and Power button to enter Fastboot mode;
• Connect your phone to PC using USB cable and click “Unlock”.

Also make sure to have the developer mode incl. the usb debugging enabled.

For being able to use fastboot under Windows I had to install the USB drivers for my phone first. I took the file from https://droidfilehost.com/download/download-xiaomi-usb-driver-for-windows/. After the installation nothin was changed but I was able to select the driver for the “Android” device from the list of predefined devices – “Android Composite ADB Interface”.

It is important that you are logged in to the same Xiaomi account in the unlock tool as you are logged in in your phone. Otherwise it won’t work because Xiaomi asks you to wait for 14 days to rethink your decision to unlock the device.

With the driver in place and the phone in fastboot mode the unlock tool finally recognised the phone and allowed me to klick unlock after having waited for the cooldown phase.

Install Arrow OS

Adb and fastboot come with Android Studio which I had already installed. So I took these tools simply from there. Further I downloaded the latest official release from Arrow OS – https://arrowos.net/download. Vanilla + Gapps build. Next to this we need a new recovery. So I also fetched the latest TWRP from https://dl.twrp.me/perseus/. The installation procedure is described under https://forum.xda-developers.com/t/rom-11-0-0-perseus-arrowos-11-0-official-weekly.4176405/#post-83706165 but that only gives directions and won’t help you if you don’t know the commands.

// start phone in fastboot mode (power + sound down = bootloader)

// install TWRP
fastboot flash recovery twrp.img

// reboot into recovery - (power + sound up = recovery)
fastboot reboot recovery

// wait until TWRP is started and allow it to do changes to the fs
// "Make FULL WIPE (system/vendor/data/dalvik/cache) and FORMAT DATA - YES" from within TWRP.

// copy downloaded files from my computer to the device
adb push vanilla.zip /sdcard/vanilla.zip
adb push gapps.zip /sdcard/gapps.zip

// install vanilla.zip via TWRP
// install gapps.zip via TWRP

// reboot device

The device should now boot into Arrow OS and up to now I haven’t found any problems.

Sidenote

In general the installation procedure for a custom rom hasn’t really changed so my experience from experimenting with my old Nexus 3 helped a lot avoiding to brick my device.

Important: I wrote this post from memory because I didn’t want to start from scratch to document it. Please write me if I missed something important or something is wrong. If you decide to follow the steps described in this post you do so on your own risk.

The whole process seems to be very familiar if you’ve rooted a nexus device before. With CWM my phone didn’t start anymore so I tried openrecovery which worked like a charme:

Preparation

• Download openrecovery from http://www.androidfilehost.com/?fid=23212708291678610
• If you haven’t already done that download and install the Android SDK tools for your system from http://developer.android.com/sdk/index.html. You’ll need to have the Android Platform tools installed
• (Windows only) You may need device drivers for the Nexus 5 under windows – but as I only have ubuntu machines I stick to linux ;-)
• (optional) To be able to restore your phone if something goes wrong it is also advisable to download the factory image from google from https://developers.google.com/android/nexus/images#hammerheadkrt16m. There are lots of tutorials how to flash this so I’ll also leave this to you.

Installation

• Copy the downloaded openrecovery-twrp-2.6.3.2-hammerhead.img to your android-sdk-linux/platform-tools folder and cd to that folder
• Change to superuser with

sudo su

• Reboot your phone to recovery mode (shut down the phone and hold volume down and power button to turn it on again)
• Check that your device is recogniced with

./fastboot devices

• Unlock the bootloader (This will erase all your data!!!)

./fastboot oem unlock
./fastboot reboot-bootloader
sleep 5

• Flash the recovery image with

./fastboot flash recovery openrecovery-twrp-2.6.3.2-hammerhead.img
./fastboot reboot-bootloader
sleep 5

• Go to recovery mode (change selection on phone with vol +/- and select with power button)
• In recovery mode choose to reboot the phone from within recovery mode. The application will ask if you want to root the phone. Say yes ;-)
• The phone boots after that. When finished start the SuperSU application which tells you that you haven’t finished yet. Choose TWRP when asked how to finish installation. The phone will reboot again and you are done.

Feel free to post questions. For me it worked exactly as described here.

I recently upgraded my Samsung Nexus S to Cyanogenmod 10.1.2 as there won’t be factory images from google anymore. The phone has to be unlocked as described in previous posts in this category.

First I downloaded the following files:

• Clockwork Recovery 6.0.3.6
• Cyanogenmod 10.1.2
• Google Apps for Jellybean

Then I copied the two zip-file to the sdcard of the phone and bootet into the bootloader (Hold louder and on/off button to power on) to flash the recovery image from the connected notebook (you may need superuser rights on your local pc):

./fastboot flash recovery recovery-clockwork-6.0.3.4-crespo.img

After a reboot again into the bootloader I first made a factory reset, mounted the sdcard and flashed the two downloaded zip-archives beginning with cyanogenmod (the order is important). Then I rebootet my phone and it started nicely into my new cyanogenmod.

Notice! I’m not responsible if you brick your phone while following my instructions.

I first downloaded all files I needed

• recovery-clockwork-6.0.1.0-crespo.img
• On http://forum.xda-developers.com/showthread.php?t=1736645 I found the link to the OTA package from google for my device (I9023).
• Superuser-3.1.3-arm-signed.zip

Then I rebooted my phone into bootloader and flashed the recovery image to the actual version via

sudo ./fastboot flash recovery ~/recovery-clockwork-6.0.1.0-crespo.img

Then i directly started recovery mode, mounted the sdcard and installed the OTA package followed by the SuperUser package. Then I mounted /system and moved the install recovery script as usual by

./adb shell
cd /system/etc
rm install-recovery.sh.old
mv install-recovery.sh install-recovery.sh.old

Then just reboot the phone into the new 4.1.1 Jelly Bean which updates your apps at first boot and all your config and apps should stay in place and the recovery is still working after a boot of the system and is rooted. So my phone is working as expected and the upgrade took me about 30min including searching for the needed files.

If you follow my steps you do this on your own risk and I’m not responsible if you brick your phone or loose warranty.

I found an officially signed update package under http://forum.xda-developers.com/showthread.php?t=1445635 (Android 4.0.3 (Build IML74K/XXKI1 Radio/KL1 Bootloader 4.0.3 -> 4.0.4) and copied it over to my sdcard. I also copied the SuperUser-zip I used the last time. Then I rebooted into bootloader and started recovery mode. There I just installed the downloaded patch and the superuser package in this order.

Then I checked that there is no install-recovery.sh in /system/etc. I had to rename it again, as I did the last time. Then i booted my new 4.0.4 without any problems. Also the recovery mode is still working after a reboot.

ICS

First I was waiting for an OTA update but nothing happened and after looking for a way to manually do it I found some links to Google full ROMs under http://forum.xda-developers.com/showthread.php?t=1445635 and decided to try the update. I chose the “Android 4.0.3/IML74K/XXKI1 Radio/KL1 Bootloader” full rom and downloaded the package.

With this image on the sdcard of my phone, copied over USB, I rebooted my phone into the bootloader by holding power and up button to power it on. As I’ve already unlocked (fastboot oem unlock) my bootloader before I skipped this step now and there are dozens of howtos for this – but mentioned that most of these forums told me unlocking the bootloader voids warranty. In the menu I chose recovery, mounted the sd card and installed the downloaded package. After a reboot i had ICS :-)

Custom Recovery

But trying to get back into recovery I had to find out that the upgrade broke my recovery image. So I looked for the latest recovery image for crespo under http://download.clockworkmod.com/recoveries/ which was recovery-clockwork-5.0.2.0-crespo.img. I downloaded this file and flashed it with fastboot which only works if you are in the bootloader. I copied the image to my plattform-tools folder of the Android-SDK before

# verify that phone is available
./fastboot devices
...
# flash new recovery
./fastboot flash recovery recovery-clockwork-5.0.2.0-crespo.img

Now it was possible to get back into recovery. But only till next boot of the phone. There is a script installing the broken image on every boot. This can be stopped by renaming install-recovery.sh in /system/etc of the phone. I mounted /system in the recovery menu then run these commands:

./adb shell
cd /system/etc
mv install-recovery.sh install-recovery.sh.old

Now the phone was running with stock ROM without root access.

Root

I downloaded Superuser-3.0.7-efghi-signed.zip from http://androidsu.com/superuser/. There are different versions but only one for ICS. Icopied this file into the plattform-tools folder of my SDK, booted the phone into recovery, mounted the sdcard and then run this command to copy the file to the phone:

# copy the file to phone
./adb push Superuser-3.0.7-efghi-signed.zip /sdcard

Then I installed the file over the recovery menu and rebooted it. Now I have a rooted Nexus S with Android 4.0.3 and custom recovery.

Lessons learned

I shouldn’t have booted ICS after every single step to see if it is still working and to appreciate my work. All steps should be combinable by copying all needed files mentioned above to the sdcard (no matter how) and then doing the following – every step is explained above:

1. Boot into bootloader and choose recovery in the menu
2. Install new ROM
3. Reboot the phone into bootloader or get back to bootloader in another way
4. Flash recovery
5. Choose recovery in the menu
6. Rename install-recovery.sh
7. Install Superuser package
8. Reboot the phone normally

error while loading shared libraries: libncurses.so.5: wrong ELF class: ELFCLASS64
The solution is quite simple: The system has a 64bit environment, but the package from google is 32bit. So you have to install the 32bit libraries via

sudo apt-get install ia32-libs