1.2.2.3 Booting the system

eMMC has no system yet

Power off, insert the prepared SD card into the carrier microSD slot, connect HDMI, then power on—the board boots from SD.

eMMC already has a system

Default

Connect HDMI and power on; by default the board boots from eMMC.

Boot from SD instead

1. Insert the prepared SD card and connect HDMI.

2. After login, clear the boot flag on partition 2 of eMMC and reboot:

   sudo parted /dev/mmcblk0 set 2 boot off
   sudo reboot

3. U-Boot will then boot from SD. After login, mount should show root on SD partition 2 and config on SD partition 1:

   /dev/mmcblk2p2 on / type ext4 (rw,relatime,data=ordered)
   /dev/mmcblk2p1 on /boot/config type vfat

Switch back to eMMC from SD

If you booted from SD but eMMC also has a system, restore eMMC boot:

sudo parted /dev/mmcblk0 set 2 boot on
sudo reboot