Unbrick Rock

Is it bricked?
When writing update.img to nand RKBatchTool failes with following message: "Prepare IDB Fail" (or similar error messages like "IDB download failed" when writing to nand with other tools)
Radxa is "bricked". It is not really bricked, first make sure there's no SD card connected while trying to flash the device, otherwise the bootloader is corrupted at this time, you can always recover it.
To recover it:

1. Turn off Power.
2. Connect pin 8 and 9 on the nand with a needle and plug OTG USB cable in the PC.
3. After Plugin remove needle connection. In RKBatchTool the square should now show up blue (if it isn't blue, retry).
4. Click the restore button and upload an update.img

Hints

• Its useful to use a magnifying glass or (smartphone-)camera zoom to get the right pins.
• Always start counting pins on the edge of the chip where the small circle is molded in or printed on.

Linux

   sudo upgrade_tool
   List of rockusb connected
   No found rockusb,Rescan press <R>,Quit press :r
   List of rockusb connected
   DevNo=1	Vid=0x2207,Pid=0x310b,LocationID=21f	   Maskrom
   Found 1 rockusb,Select input DevNo,Rescan press <R>,Quit press :1
   Rockusb>uf /tmp/radxa-rock-alip-desktop.img
   Loading firmware...

If you see Maskrom(Normally it's Loader), that means you have successfully short cut the nand flash.