clearall.sh

#!/bin/sh

echo "=== Clear all EFI boot entries ==="
sudo apt-get --yes install efibootmgr
sudo efibootmgr -v | grep ^Boot[0-9A-F][0-9A-F][0-9A-F][0-9A-F] | cut -c 5-8 | while read boot; do
  sudo efibootmgr -v -b $boot -B
done
sudo efibootmgr -O
sudo efibootmgr -v

echo "=== Clear all partitions ==="
for dev in mmcblk0p1 mmcblk0p2 mmcblk0p3 mmcblk0p4; do
  if mount | grep $dev > /dev/null; then
    sudo umount /dev/$dev
  fi
done
sudo swapoff -a
sudo parted -s /dev/mmcblk0 rm 1 rm 2 rm 3 rm 4
sudo parted -s /dev/mmcblk0 print