[Android 12] [EXPERIMENTAL] [RE-UPLOADED] AOSP Android 12 for A21s

Search This thread

Algowata Wata

New member
Apr 13, 2022
Good day, everyone.

I just wanted to tell the fantastic developer who made this fantastic idea that I will be waiting for the U7 recovery to be finally fixed!

I'll use the U7 recovery to flash LineageOS unto my phone.

Thank you and may everyone stay safe.


New member
Apr 5, 2022

i have a sm-217f . I wanted to ask 2 things. First if i can download and install this rom on my phone and second how can i check my acutal binary ?


New member
Apr 5, 2022
After some research my phone seems to be on binary u8. Is it possible to install any custom rom on it ?


New member
May 17, 2022
Hey guys,
Same question others are having.
I am trying to use this or the LOS 18.1 for now but being on Binary U8 I think that is why I am getting stuck in boot after the reset.
With a FRP Hijacker I can get into the recovery and finish the steps only to get stuck while trying to boot and I assume its because of the Binary incompatibility.

Is there any way to downgrade Binary so I can install a rom before a newer recovery compatible with U8 comes out?
And will any U8 recovery that releases work or would it need to be specific to this device or brand?

Is TWRP something that could work?

Thanks very much,
Last edited:

Top Liked Posts

  • There are no posts matching your filters.
  • 3
    By installing this custom ROM, you are VOIDING your warranty. Also, installation of this ROM WILL TRIP KNOX PERMANENTLY, and render apps such as Samsung Health, Private Folder, (+ any apps that depend on KNOX) useless until you get the phone's motherboard replaced at the Samsung C/S center.
    Although this software is released in the hope that it will be useful, there is NO GUARANTEE that installing this will not cause any harm to your device. I TAKE NO RESPONSIBILITY FOR ANY BRICKED DEVICES, DAMAGED HARDWARE, OR ANY OTHER PROBLEMS CAUSED BY THIS ROM. You are using this ROM at YOUR OWN RISK. I strongly recommend that you DO NOT continue to the steps below UNLESS YOU FULLY UNDERSTAND WHAT YOU ARE DOING.
    While this ROM has been tested with South Korean variant of Galaxy A21s (SM-A217N, CSC changed from LUC->SKC), please keep in mind that it hasn't been tested on any other variant (such as A217F, A217M.)
    I would like to express special thanks to all the developers who contributed to the LineageOS port for Galaxy Tab S6 Lite + all the other developers who contributed to sepolicy & hardware parts for Samsung SLSI (Exynos) devices. Porting LineageOS to A21s would have been much harder without them.

    This is Android 12 ROM built from Google's AOSP sources released on October 4, 2021. The sources are based on the Lineage OS for A21s, with some modifications for Android 12.

    Samsung Proprietary Apps (Samsung Health, etc.)
    VoLTE & VoWifi (Due to Samsung's twisted & wicked IMS service)
    Auto Brightness (The phone doesn't have the sensors for it anyway)
    ExFAT-formatted SD Card & OTG (there are legal problems associated with it.)

    Working but buggy or not tested:
    Audio volume is smaller than usual (WIP)
    RIL starting up late on very rare occasions. If telephony doesn't work after reboot, please allow up to a minute.
    Cell broadcast (emergency messages) is working in South Korea, but not tested in other countries

    Working, but needs installation of additional apps:
    NFC, Screen Sharing, Wi-FI Direct works, but needs installation of additional apps to work
    Browser app is not installed by default. Installing Firefox or Chrome from Google Play is recommended
    GPS & Location services don't work when GApps are not installed.
    This ROM is not compatible with TWRP due to File-based encryption.
    The ROM is NOT ROOTED by default. In order to root it, install Magisk from official source.

    Everything else not mentioned above

    Based on official release, whereas GSI is based on Beta 5
    Working MTP
    Working NFC
    Working Cell Broadcast
    Fixed Fingerprint removal bug
    Camera works up to 48MP (GSI camera is fixed @ 12MP)
    Double-tap-to-wake is working
    Model number correctly matches with the actual device (shows SM-A217N instead of AOSP on ARM64)
    Updated kernel graphics driver to the latest from ARM

    1. BEFORE INSTALLING, make sure that you have UNLOCKED the bootloader of your device. This is a great guide that show how to do it. Also, the phone must be on the Stock ANDROID 11. If you are on binary U6/U7, please use the recovery tar for U6/U7.

    2. Download the Lineage Recovery, ROM, Google Apps, ADB, and Odin. Unzip ADB and Odin to somewhere appropriate. Save the ROM images to the folder where you unzip ADB/Fastboot

    - ROM: super.img. boot.img, dtbo.img, recovery(U5), recovery(U6), recovery(U7)
    - ADB and Fastboot
    - Odin
    - Kernel Source
    - Google Apps(Flame)


    3. Enable USB Debugging on the device. Go to settings->About phone->Software information, and tap the build number several times until you see the notification that the devloper settings have been enabled. After enabling developer settings, go to settings->developer settings and check USB debugging.

    4. Open Command Prompt, and type "cd <the path where you saved ADB to>".

    5. On the phone, start holding down the Volume Up and Down keys. KEEP THE KEYS PRESSED UNTIL THE PHONE REBOOTS AFTER YOU TYPE THE COMMAND IN THE NEXT STEP.

    6. While holding the keys down. type in the command "adb reboot recovery" on the command line.

    7. After the phone reboots into download mode, press volume up to continue. Make sure that you see the "OEM LOCK: OFF" before continuing.

    8. Open Odin. After opening Odin, click on AP, and select the Lineage Recovery Tar file that you downloaded in the step 2. After that, click on Start.

    9. After a few seconds, if everything goes well, Odin should show "PASS" and the device should reboot into Lineage Recovery. After the device enters recovery, tap on Advanced->Enter fastboot. In some cases, touchscreen may be unresponsive or slow. If that happens, use Volume Keys to navigate and Power key to select. KEEP THE DEVICE CONNECTED TO THE COMPUTER.

    10. After choosing Enter fastboot, type the following lines in the Command Prompt and press enter:
    10-1. "fastboot flash boot boot.img" ---> this takes around 5~10 seconds.
    10-2. "fastboot flash dtbo dtbo.img" ---> this takes around 5~10 seconds.
    10-3. "fastboot flash super super.img" ---> this takes several minutes.

    11. After the steps above are complete, choose Enter recovery. After the phone enters recovery, choose Apply update->Apply from ADB

    12. After choosing Apply from ADB, type "adb sideload <the path where you saved Google apps to>" on the Command Prompt and press enter.

    13. After about 1-2 minutes, installation should be complete. Again, ADB might show "Failed to read command" errors. As long as the phone says that it was success, this is no problem. After installing, click on the "back" icon on the top of the phone.

    14. Choose Factory reset->Format data/factory reset, and reboot the device.

    15. If everything went well, the phone should reboot into Android 12 AOSP. Set up the device and Enjoy!

    2021-10-19: Initial Release (AOSP 12.0.0_r2)
    2021-10-21: Updated to AOSP 12.0.0_r3
    2021-11-03: Updated to AOSP 12.0.0_r13 & added U7 support
    2021-11-22: Fixed graphics issue, fixed battery issue (when battery level sometimes dropped by more than 2-3% on reboot), and fixed force crash when choosing Battery Manager in Settings
    2021-11-25: Updated to AOSP 12.0.0_r15, changed battery mechanism to make it more accurate
    2021-11-27: Kernel GPU driver update (R33P0 -> R34P0), LTE is now enabled by default
    2021-12-10: Updated to AOSP 12.0.0_r16, removed the annoying search box widget on the home screen
    2022-01-01: EGL graphics driver update to improve performance, minor bug fixes related to some apps.

    Thread locked and download links removed due to lack of kernel sources. @grccorps please read your PM to get the thread reopened.

    garylawwd - Forum Moderator
    Will the U7 recovery be fixed? I really want to flash a custom rom onto my a21s...
    This is great!

    Do you working on this ROM for A21s, or you working on LineageOS 18 A11, paralel with this ROM?
    Yes. I am also working on Lineage 18. Actually, the source code for this ROM is based on the source code for the Lineage 18. (of course, along with some modifications)
    i got this when type and enter "fastboot flash boot boot.img"

    C:\Users\nussa\Downloads\platform-tools>fastboot flash boot boot.img
    < waiting for any device >

    nothing showing in phone log