Jump to content

Lenovo TAB 2 A8-50F (lenovo-a8-50f)

From postmarketOS Wiki
Lenovo TAB 2 A8-50F
Lenovo TAB 2 A8-50F on the Xfce4 desktop, showing the About window
Lenovo TAB 2 A8-50F on the Xfce4 desktop, showing the About window
Manufacturer Lenovo
Name TAB 2 A8-50F
Codename lenovo-a8-50f
Model CHANGE_ME
Released 2015
Type tablet
Hardware
Chipset MediaTek MT6735
CPU CHANGE_ME
GPU CHANGE_ME
Display CHANGE_ME
Storage 16 GB
Memory 1 GB
Architecture aarch64
Software
Original software
The software and version the device was shipped with.
Android 5.0
Extended version
The most recent supported version from the manufacturer.
Android 5.1
postmarketOS
Pre-built images
Whether pre-built images are available from the postmarketOS Installation page.
no
Mainline
Instead of a Linux kernel fork, it is possible to run (Close to) Mainline.
no
pmOS kernel
The kernel version that runs on the device's port.
3.10.61
Unixbench score
Unixbench Whetstone/Dhrystone score. See Unixbench.
0.0
Features
Flashing
Whether it is possible to flash the device with pmbootstrap flasher.
Partial
USB Networking
After connecting the device with USB to your PC, you can connect to it via telnet (initramfs) or SSH (booted system).
Works
Internal storage
eMMC, SD cards, UFS...
Untested
SD card
Also includes other external storage cards.
Untested
Battery
Whether charging and battery level reporting work.
Untested
Screen
Whether the display works; ideally with sleep mode and brightness control.
Partial
Touchscreen
Works
Multimedia
3D Acceleration
Untested
Built-in DVB
TV tuner/DVB device
Untested
Audio
Audio playback, microphone, headset and buttons.
Broken
Camera
Untested
Camera Flash
Untested
IR TX
Untested
IR RX
Untested
Connectivity
WiFi
Untested
Bluetooth
Untested
Ethernet
Untested
GPS
Untested
NFC
Near Field Communication
Untested
Modem
Calls
Untested
SMS
Untested
Mobile data
Untested
Miscellaneous
FDE
Full disk encryption and unlocking with unl0kr.
Untested
USB-A
Whether the full-sized USB-A port works.
Untested
SATA/eSATA
Untested
USB OTG
USB On-The-Go or USB-C Role switching.
Works
HDMI/DP
Video and audio output with HDMI or DisplayPort.
Untested
Sensors
Accelerometer
Handles automatic screen rotation in many interfaces.
Untested
Magnetometer
Sensor to measure the Earth's magnetism
Untested
Ambient Light
Measures the light level; used for automatic screen dimming in many interfaces.
Untested
Proximity
Untested
Hall Effect
Measures magnetic fields; usually used as a flip cover sensor
Untested
Haptics
Untested
Barometer
Sensor to measure air pressure
Untested
Power Sensor
Sensor to monitor current, voltage and power. Not fuel gauge!
Untested

Contributors

Users owning this device

  • Oreeeee (Notes: Damaged backlight in the corner)


Installation

  1. Use generic fastboot unlock procedure with the `fastboot oem unlock` command to unlock the bootloader. Use adb to reboot to bootloader. You might need to confirm the unlock by using the Vol Up button.
  2. Power off the device, unplug from PC.
  3. Open SP Flash Tool, select TWRP's scatter file.
  4. Click on the Download button while the device is unplugged.
  5. Plug in the tablet to the PC.
  6. After flashing TWRP in SP Flash Tool succeeds, unplug the tablet IMMEDIATELY!
  7. Boot into TWRP by holding Volume Up + Volume Down buttons and plugging in the tablet into a PC. Make sure to not let the tablet show the charging screen or boot into Android, and don't turn on the tablet using the power button, as that will trigger an integrity check that will restore the stock recovery. Flashing postmarketOS removes said integrity checks. This might require trying to reflash TWRP multiple times (repeat steps 4 to 7).
  8. (Optional) Make a stock system backup to an SD card.
  9. Once you're in TWRP, go to Advanced and enable ADB sideloading.
  10. Use `pmbootstrap install --android-recovery-zip` to flash postmarketOS.

Notes

Stock ROM will overwrite TWRP if it's flashed. In that case, an error message will appear and recovery will go back to stock. The cause is unknown, but it's either a signature check (/etc/recovery.sig in /system), or a CRC/filecount check (/data/recovery_rootcheck in /system). It does not happen when postmarketOS is flashed, and TWRP is loadable if you avoid loading the stock kernel, so it's likely something in the stock initramfs.

Graphics only work through framebuffer device. LightDM requires additional configuration. LightDM will not start if boot splash is enabled. Any interaction with audio devices causes a kernel panic.

A8-50F is the WiFi only model. There were also 2 similar models with 4G - A8-50L and A8-50LC. A8-50L had hardware support for 4G, but it was disabled at software level. A8-50LC only released in selected regions. It was possible to flash A8-50LC firmware onto A8-50L to bypass the artificial 4G block. A8-50L and A8-50LC were mostly compatible with eachother, A8-50F is distinct but to my knowledge, close enough together, so if A8-50F starts working, a port to A8-50L/LC could be viable.

See also