Samsung Galaxy Tab A7 Lite (samsung-gta7litewifi)

From postmarketOS
Samsung Galaxy Tab A7 Lite
The postmarketOS "Loading..." screen on a Samsung Galaxy Tab A7 Lite
The postmarketOS "Loading..." screen on a Samsung Galaxy Tab A7 Lite
Manufacturer Samsung
Name Galaxy Tab A7 Lite
Codename samsung-gta7litewifi
Released 2021
Category testing
Pre-built images no
Original software Android (One UI)
Original version 11
Extended version 13
postmarketOS kernel 4.19.191
Hardware
Chipset MediaTek Helio P22T (MT8768)
CPU ARM Cortex A53 MPCore
GPU PowerVR GE8320
Display 800x1340 TFT LCD
Storage 32GB or 64GB, depending on the specific model
Memory 2GB, 3GB, or 4GB, depending on the specific model
Architecture AArch64
Type tablet
Unixbench Whet/Dhry score 0.0
Features
USB Networking
Works
Flashing
Works
Touchscreen
Broken
Display
Partial
WiFi
Broken
FDE
Works
Mainline
Broken
Battery
Broken
3D Acceleration
Broken
Audio
Broken
Bluetooth
Broken
Camera
Broken
GPS
Broken
Internal storage
Works
USB OTG
Works
Sensors
Accelerometer
Broken
Magnetometer
Ambient Light
Broken
Proximity
Hall Effect
Barometer
Power Sensor
Broken
Misc
Built-in DVB
Camera Flash
Broken
Memory Card
Haptics
Ethernet
Works
FOSS bootloader
Broken


Icon WARNING: Make sure that you are prepared to lose functionality before installing postmarketOS. Samsung Knox will blow an efuse when the OS is modified that will permanently disable Knox-only features like Samsung Pay, and you will NEVER be able to use those features again.
Notice While the kernel compiles and flashing is available, this device is in an extremely early state of development. Here Be Dragons

Contributors

hexaheximal

Users owning this device

  • Hexaheximal (Notes: maintaining the postmarketOS port, 3GB RAM 32GB eMMC model)
  • Zillion (Notes: T220, Currently running OneUi for kernel development)


Status

This postmarketOS port is incredibly buggy, but does boot.

The only known working desktop environment option is i3, but the touchscreen does not work. XFCE just causes a crash-reboot.

Unlocking the bootloader

At least at first, the Android settings app does not allow you to enable bootloader unlocking. (On some devices it requires that it can connect to Samsung's servers first, but I would not recommend ever connecting it to the internet on stock Android)

However, it can be done with mtkclient:

$ mtk e metadata,userdata,md_udc
$ mtk da seccfg unlock

If it worked you should see a warning like this:

Samsung-gta7litewifi-dm-verity-warning.jpg

Do not panic! Your device is not broken!

If you *don't* see that warning, then it didn't work.

You can safely skip the warning, although on stock Android it might fail to boot in which case you will need to choose the factory reset option to clear userdata etc. again.

Installation

Install pmbootstrap and then run the following commands:

$ pmbootstrap init
$ pmbootstrap install
$ pmbootstrap flasher flash_kernel
$ pmbootstrap flasher flash_rootfs

Reading logs

Before reading the logs, make sure to install mtkclient and then erase the expdb partition so the existing boot logs don't get mixed in and get confusing:

$ mtk e expdb

Once you have done that, boot the device. As soon as it powers off during a bootloop (and if it doesn't, hold down Power + Volume Down for ~10 seconds), run these commands:

$ mtk r expdb /tmp/expdb.bin
$ mtk reset # turns the device off, optional
$ cat /tmp/expdb.bin

Please note that the kernel part of the logs is quite a mess - it does not use proper newlines and instead uses what seems to be null bytes.


Downstream kernel status

The downstream kernel is surprisingly capable, but still lacking in many ways. For example, audio is currently broken and the touchscreen does not fire any events. However, if you use a USB-C OTG dock to connect it to a keyboard & mouse, it works perfectly fine. Ethernet works fine if you do it that way too.

Mainline kernel status

The MT6765 close-to-mainline kernel does not boot due to the android bootloader refusing to boot with a dummy dtbo.

See also