Samsung Galaxy Tab 3 7.0 (samsung-lt023g)

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Samsung Galaxy Tab 3 7.0
Samsung Galaxy Tab 3 7.0
Samsung Galaxy Tab 3 7.0
Manufacturer Samsung
Name Galaxy Tab 3 7.0
Codename samsung-lt023g
Released 2013
Original software Android 4.4.2 on Linux 3.4.5
Hardware
Chipset Marvell PXA986
CPU Dual-core 1.2 GHz Cortex-A9
GPU Vivante GC1000
Display 1024×600 TFT
Storage 16GB
Memory 1GB
Architecture armv7
Unixbench Whet/Dhry score 564.6
Features
USB Networking
Works
Flashing
Partial
Touchscreen
Works
Display
Works
WiFi
Works
Xwayland
Works
FDE
Works
Mainline
Battery
Works
3D Acceleration
Accelerometer
Works
Audio
Bluetooth
Partial
Camera
Works
GPS
Mobile data
SMS
Calls
USB OTG
Firefox on Matchbox

Entering flash mode

  • Power down the device, then press and hold Volume Down + Home + Power simultaneously.
  • Once the device vibrates, release Power, but keep Volume Down and Home held.
  • The device will ask you if you wish to upload a custom OS. Press Volume Up to confirm.
  • Once the device displays "Odin mode" in the top-left of the screen, it is ready for flashing.

Entering recovery mode

  • Power down the device, then press and hold Volume Up + Home + Power simultaneously.
  • Once the device vibrates, release Power, but keep Volume Up and Home held.

Installing the kernel

This can be done via pmbootstrap flasher flash_kernel after entering flash mode.

What works

  • Booting off a microSD card
  • Booting from system partition using Android recovery ZIP option
  • Display
  • Touchscreen
  • USB networking
  • Full disk encryption
  • Physical buttons
  • Touch keys
  • Backlight brightness
  • Battery indicator
  • Wayland
  • X11
  • Front Camera(and probably back but didn't figure out how to switch cameras)
  • WiFi
  • Sensors
  • Bluetooth(only shows available devices. Still looking for a way to connect to a device)

What does not work

  • Cellular networking
  • 2D and 3D Acceleration
  • Audio
  • Flashing with flash_rootfs

Everything else is untested as of writing this.

How hpagseddy get camera working

Right now it's not usable for daily use, just for testing camera quality and checking if camera is working or not. I used "motion" package from alpine linux to capture pictures. If you want to test it too, just use "apk add motion" command to install that package. Then simply type "motion" and it will start capturing pictures nearly every second. If it doesn't capture pictures or pictures are just black squares then your camera isn't working. For opening pictures, i used feh image viewer to view images but every gallery app works great.

How to get WiFi working

Install linux-firmware-mrvl to get the necessary firmware files, reboot the device after install. Run sudo ifconfig mlan0 up, then configure wpa_supplicant:

$ wpa_passphrase YOUR_SSID YOUR_PASSPHRASE | sudo tee /etc/wpa_supplicant/wpa_supplicant.conf

Then run:

sudo rc-service wpa_supplicant start
sudo udhcpc -i mlan0

Note: You need to turn rndis0 off using sudo ifconfig rndis0 down if you used USB Internet. Also remove usb_internet.start from /etc/local.d. If starting the service didn't work, start wpa_supplicant manually with:

sudo wpa_supplicant -u -Dnl80211 -B -c /etc/wpa_supplicant/wpa_supplicant.conf -imlan0

You might need to kill the existing process if the wpa_supplicant service fails to start (find it for example with htop).

About GPU

The GPU is Vivante GC1000 which has open source drivers but we can't get it work yet. The reverse engineered driver is called etnaviv and the compiling process is a little bit complex. If anyone figures it out dont forget to tag @hpagseddy at postmarketos matrix server. Galaxy tab 4 7.0 have same GPU, and plasma mobile seems to work better with hw acceleration, but OpenGL is failing.

Links