Erase eMMC Storage

There are 3 different ways to erase all data on the onboard eMMC storage:

  • Serial Mode (For developers)
  • Interrupt Mode
  • CLI Mode
  • Refer to this guide to setup the Serial Tool for your VIM
  • Once again, ensure you’ve done the correct connections and setup
  • Hit SPACE key at the moment of bootup to stop autoboot. This step will make your VIM enter into u-boot mode
  • Type store boot_erase bootloader on the terminal of u-boot, and wait for the erasure process to complete
  • Type reboot or press the Reset button
  • Use the following as a reference:
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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
Tips

If the erasure process completed successfully, the terminal should look like this when you power on your device:

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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;

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

  • Carry out normal upgrading via USB-C Cable or TF Card
  • Manually interrupt the upgrading process (forcefully disconnect after 15% is recommended). For example, unplug the USB-C cable or the TF card
  • Power on your VIM again, and you’ll find that all the data on the eMMC has been erased

This approach is suitable for a VIM that has Linux installed:

  • Power on and boot up
  • Open a terminal, and run dd to fill your bootloader partition with zeros:
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root@Khadas:~# 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
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