Serial Mode (Developers)

1. Connect your PC to your SBC using a Serial Debug Tool.
2. Just as your SBC is booting-up, hit SPACE on your keyboard to enter U-Boot mode.
3. Type store boot_erase bootloader into the U-Boot console, and wait for the erasure process to complete.
4. After erasure is complete, type reboot or press the RESET button on your SBC.

Use the following serial Terminal print-out as a reference:

kvim4# store boot_erase bootloader
GUID Partition Table Header signature is wrong: 0x0 != 0x5452415020494645
GUID Partition Table Header signature is wrong: 0x0 != 0x5452415020494645
gpt is invalid


Caution! Your devices Erase group is 0x400
The erase range would be change to 0x0~0x23ff

8191 blocks erased: OK


Caution! Your devices Erase group is 0x400
The erase range would be change to 0x0~0x23ff

8191 blocks erased: OK


Caution! Your devices Erase group is 0x400
The erase range would be change to 0x0~0x23ff

8191 blocks erased: OK
kvim4# reboot

If the eMMC has been erased, the serial Terminal should show this print-out when your SBC powers-on:

T7:BL:055c20;ID:7CFDCF5E6052BDEC;FEAT:30F:1FFF0000:B002F:1;POC:CF;RCY:0;OVD:0;DFU:0;SD:2002;eMMC:0;RD-0:0;CHK:1;RD-1:0;CHK:1;RD-2:0;CHK:1;SPINOR:0;RD-0:0;CHK:1;RD-1:0;CHK:1;USB:ADFU�T7:BL:055c20;ID:7CFDCF5E6052BDEC;FEAT:30F:1FFF0000:B002F:1;POC:CF;RCY:0;OVD:0;DFU:1;USB:0;RD-00:0;

Interrupt Mode

This erasure method is suitable for all products that use the Amlogic SoC:

1. Carry out eMMC flashing via a USB-C cable.
2. Manually interrupt the upgrading process (forcefully disconnect after 15% is recommended). For example, unplug the USB-C cable or eject the TF card.
3. Power on your SBC again, and you'll find that all the data on the eMMC has been erased.

CLI Mode

This erasure method is suitable for an SBC with Linux installed:

1. Power on and boot up.
2. Open a Terminal, and run dd to fill your bootloader partition with zeros:

khadas@Khadas:~$ sudo dd if=/dev/zero of=/dev/bootloader
dd: writing to '/dev/bootloader': No space left on device
8193+0 records in
8192+0 records out
4194304 bytes (4.2 MB, 4.0 MiB) copied, 1.1226 s, 3.7 MB/s
root@Khadas:~# reboot