Hi everyone, this is a short guide on how to flash a GSI on the A7 Lite (without TWRP).
Its a nice little tablet for the price but it doesn't have a very powerful SOC and for me the One UI is barely usable on this device. The launcher and the whole system UI feel extremely laggy, but apps generally run fine.
I tried phhusson's custom Android 12 GSI and the device was almost resurrected. Much much less UI lag and the battery life is the same as stock ROM. The only thing i found not working is MTP but i don't need it.
Since i saw a couple users here asking about GSIs i decided to make a very simple guide.
As always do this at your own risk. You may brick your device. You will void your warranty.
Follow the guide only if you know what your are doing. Read each step carefully and avoid copy pasting stuff randomly.
I won't go deep into details as i believe you should have some basic knowledge if you decide to do this.
The procedure sould work for both T220 and T225 (i tested it on a T220).
I did this on Windows using WSL for some of the steps.
Sources
Thanks to
@kkoo and
@Brepro1 for the useful info
-
https://forum.xda-developers.com/t/...sing-odin-without-twrp-phh-lineageos.4114435/
-
https://forum.xda-developers.com/t/...r-img-and-flashing-our-modifications.4196625/
Requirements
- Unlocked bootloader
If you haven't done this already follow the steps in parts 1-2 from:
While some of these instructions are copied from other sources, I combined all the different things I learned, because no one guide was sufficient, and all needed additional info, so I expanded it all to one place. Part I is partly from...
forum.xda-developers.com
- Latest official ROM
I used T220XXU1AVE1 for EUX region
Samsung Galaxy Tab A7 Lite Firmware Download SM-T220 Free Download ⭐ Official and fast update ⭐ Max speed and free download ⭐ Best Samsung Galaxy website
samfw.com
- Download your preferred GSI
I used AOSP 12.1 v414 with gapps from phhusson
Notes about tinkering with Android Project Treble. Contribute to phhusson/treble_experimentations development by creating an account on GitHub.
github.com
- Clean vbmeta.img from Google
Tools
- lz4
Extremely Fast Compression algorithm. Contribute to lz4/lz4 development by creating an account on GitHub.
github.com
- simg2img
Hello, although I'm working in Linux (VM too) I rewrote the SIMG2IMG so far for Windows (PE32, x86) Usage: simg2img.exe -i -o Optional: -d for debugging messages, listing all chunks of the image...
forum.xda-developers.com
- lpunpack and lpmake
Please see this URL https://android.googlesource.com/platform/build.git/+/eec4a7cba4face3370acb6293ab357879920b467 and this for more information. Hi everyone. I'm surprised I havent seen a thread about ota tools yet and lpunpack. This zip file...
forum.xda-developers.com
- tar-md5-script-tool
Use the attached tar-md5-script-tool.zip
Steps
1. Extract official ROM files (BL, AP, CP, CSC)
2. Extract AP .tar.md5
3. Decompress the extracted super.img.lz4
Code:
lz4 -d super.img.lz4 super.img
4. Convert the sparse super.img
Code:
simg2img super.img super.ext4.img
5. Unpack super.ext4.img
I got 4 partitions in my image (should be the same for all T220/T225 ROMs):
- odm.img
- product.img
- system.img
- vendor.img
6. Replace system.img with your GSI (rename it to system.img)
7. Get the size of all partitions and the size of the original super.ext4.img (not the sparse super.img)
Code:
stat -c '%n %s' IMG_FILE.img
8. Repack super.img
Code:
lpmake --metadata-size 65536 \
--super-name super \
--metadata-slots 2 \
--device super:ORIGINAL_SUPER_IMG_SIZE \
--group main:SUM_OF_ALL_PARTITIONS_SIZES \
--partition odm:readonly:ODM_PARTITION_SIZE:main \
--image odm=./odm.img \
--partition product:readonly:PRODUCT_PARTITION_SIZE:main \
--image product=./product.img \
--partition system:readonly:SYSTEM_PARTITION_SIZE:main \
--image system=./system.img \
--partition vendor:readonly:VENDOR_PARTITION_SIZE:main \
--image vendor=./vendor.img \
--sparse \
--output ./super_new.img
Replace ORIGINAL_SUPER_IMG_SIZE, SUM_OF_ALL_PARTITIONS_SIZES, ODM_PARTITION_SIZE, PRODUCT_PARTITION_SIZE, SYSTEM_PARTITION_SIZE, VENDOR_PARTITION_SIZE with the values you obtained in step 7.
Read lpmake docs for a more detailed expalation of the args used above:
9. Compress the repacked super_new.img
Code:
lz4 -B6 --content-size super_new.img super_new.img.lz4
10. Compress the clean vmbeta.img
Code:
lz4 -B6 --content-size vbmeta.img vbmeta.img.lz4
11. Extract tar-md5-script-tool.zip
12. Put all the *.img.lz4 files extracted from AP .tar.gz in tar-md5-script-tool dir
13. Replace super.img.lz4 and vbmeta.img.lz4 in tar-md5-script-tool dir with your repacked and compressed super_new.img.lz4 (rename it to super.img.lz4) and the clean compressed vbmeta.img.lz4
14. Run batch.bat in tar-md5-script-tool dir
You will find the new AP .tar.md5 in the temp-folder subdir
15. Flash your custom AP .tar.md5 with Odin along with BL, CP, CSC from original ROM
16. Reboot into recovery and do a factory reset
17. Done