Amlogic notes

• Radxa Zero: Maskrom \ Fastboot \ Wifi

You may need to erase Android from; or flash mainline u-boot to; the eMMC before booting from SD.
I found using fastboot to be the quickest and easiest method when using Linux.

Put the device in maskrom mode and run lsusb to verify.

Bus 001 Device 048: ID 1b8e:c003 Amlogic, Inc. GX-CHIP

Run the following to flash mainline u-boot. When done. power down board, insert SD and power on.

sudo apt update; sudo apt install -y python3-pip fastboot
sudo pip3 install pyamlboot --upgrade
wget -cq https://github.com/pyavitz/debian-image-builder/raw/feature/files/boot/uboot/radxazero/fastboot-loader.bin
wget -cq https://github.com/pyavitz/debian-image-builder/raw/feature/files/boot/uboot/radxazero/u-boot.bin
boot-g12.py fastboot-loader.bin
sudo fastboot flash 0x200 u-boot.bin
sudo fastboot reboot

• Radxa Zero: LED Overlay Support (rev 1.5 is gpio 10)

fdtoverlays ../amlogic/overlays/meson-g12a-gpio-8-led.dtbo
fdtoverlays ../amlogic/overlays/meson-g12a-gpio-10-led.dtbo