====== VIM4 Erase eMMC ======

There are three methods to erase the eMMC:

  * Serial Mode (Developers)
  * Interrupt Mode
  * CLI Mode

<tabbox Serial Mode (Developers)>

  - Connect your PC to the SBC using a [[products:sbc:vim4:development:setup-serial-tool|Serial Debug Tool]].
  - As the SBC is booting-up, press ''SPACE''on the keyboard to enter the U-Boot mode.
  - Type ''store boot_erase bootloader'' into the U-Boot console, and wait for the erasure process to complete.
  - After erasure is completed, type ''reboot'' or press the ''RESET'' button on your SBC.

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

```shell
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:

```txt
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;
```

<tabbox Interrupt Mode>

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

  - Carry out eMMC flashing via a [[products:sbc:vim4:install-os:install-os-into-emmc-via-usb-tool|USB-C cable]].
  - Manually interrupt the upgrading process (forcefully disconnect after 15% is recommended). For example, unplug the USB-C cable or eject the TF card.
  - Power on your SBC again, and you'll find that all the data on the eMMC has been erased.

<tabbox CLI Mode>

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

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

```sh
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
```
</tabbox>