Samsung Galaxy SIII SCH-I535 (samsung-d2vzw)

How to enter flash mode
Set phone to ODIN mode

1. Turn off phone 2. Connect USB cable 3. Hold VOLUME_DOWN + HOME + POWER until you get Warning!! screen 4. Push VOLUME_UP to continue to ODIN mode screen

Step 1: Flash the system to an SD card
Start by flashing postmarketOS onto an SD card. Follow the usual bootstrap process, but select samsung-d2vzw as the device.

Step 2: Enter ODIN mode
To enter ODIN mode, follow these steps:

1. Turn off phone 3. Hold Volume Down + Home + Power until you get Warning!! screen 2. Connect USB cable 4. Push Volume up to continue to ODIN mode screen

Step 3: Flash the kernel via ODIN mode
Now, use Heimdall to flash the image with -boot at the end to your boot partition. Make sure that you extract it before flashing it (the downloaded file is a compressed .tar.xz archive).

Flash it with this command:

heimdall flash --BOOT  --verbose

Note that it's important to write BOOT in all capitalised letters, as otherwise you will get an error about the partition not being found in the PIT.

After that's done, your device should now automatically reboot into postmarketOS! The results should be similar to the image below: