Clearing the eMMC¶

The following instructions explain how to clear any existing partitions within the eMMC and any saved u-boot environment.

• Run unmount on existing partitions if they exist
  

  root@mitysom-am62xx:~# umount /dev/mmcblk0p*
  

• Delete the partition table
  

  root@mitysom-am62xx:~# sfdisk --delete "/dev/mmcblk0" 
  The partition table has been altered.
  Calling ioctl() to re-read partition table.
  [   78.132857]  mmcblk0:
  Syncing disks.
  

• Wipe the boot files on the eMMC boot0 hw partition by enabling write access, and then writing zeros across the whole thing.
  

  root@mitysom-am62xx:~# echo 0 > /sys/block/mmcblk0boot0/force_ro
  root@mitysom-am62xx:~# dd if=/dev/zero of=/dev/mmcblk0boot0 bs=512