Amlogic notes

USB Boot

make all board=$board
make usbboot board=$board

Flash the IMG to an USB drive and latter to an SD card, insert both the USB drive and SD card into the
unit and power on.

On the Odroid N2 you can also remove petitboot and replace it with u-boot. Although I have had success
doing it this way, I have also had fails.

Recovery; https://wiki.odroid.com/odroid-n2/os_images/petitboot

Odroid N2/+

• Remove Petitboot

NOTE: Detach eMMC module and boot from SDCARD. This will not work correctly if the module is still
      attached to the unit.

Add overlay to /boot/extlinux/extlinux.conf
fdtoverlays ../amlogic/overlays/meson-g12b-odroid-n2-spi.dtbo

Load the PMENU:
Petitboot: select exit to shell and erase /dev/mtd{0,1,2,3}
flash_eraseall /dev/mtd0
flash_eraseall /dev/mtd1
flash_eraseall /dev/mtd2
flash_eraseall /dev/mtd3
reboot

Check /dev/mtdblock0
odroid: ~  $ lsblk
NAME         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
mtdblock0     31:0    0     8M  0 disk

Flash u-boot to /dev/mtdblock0
sudo dd if=/lib/u-boot/u-boot.bin of=/dev/mtdblock0

Remove overlay from /boot/extlinux/extlinux.conf
#fdtoverlays ../amlogic/overlays/meson-g12b-odroid-n2-spi.dtbo

Reboot the unit ...

Boot order: usb sd emmc

• Update SPI

Depends: sudo apt install -y mtd-utils

Add overlay to /boot/extlinux/extlinux.conf
fdtoverlays ../amlogic/overlays/meson-g12b-odroid-n2-spi.dtbo

Reboot the unit ...

odroid: ~  $ ls /dev/mtd*
/dev/mtd0  /dev/mtd0ro  /dev/mtdblock0

sudo flash_eraseall /dev/mtd0

Result:
Erasing 8192 Kibyte @ 0 -- 100 % complete

sudo dd if=/lib/u-boot/u-boot.bin of=/dev/mtdblock0

Result:
2252+1 records in
2252+1 records out
1153392 bytes (1.2 MB, 1.1 MiB) copied, 16.2089 s, 71.2 kB/s

Remove overlay from /boot/extlinux/extlinux.conf
#fdtoverlays ../amlogic/overlays/meson-g12b-odroid-n2-spi.dtbo

Reboot the unit ... done.