Source: Raspberry Pi 4 boot EEPROM
- update system's package list
sudo apt update
- upgrade all installed packages to their latest versions
sudo apt full-upgrade -y
- select the stable bootloader release series
sudo sh -c 'echo FIRMWARE_RELEASE_STATUS=\"stable\" > /etc/default/rpi-eeprom-update'
- install current stable bootloader
sudo rpi-eeprom-update -a
- reboot
sudo reboot
Source: Pi4 Bootloader Configuration
- extract configuration file
sudo cp /lib/firmware/raspberrypi/bootloader/stable/pieeprom-*-*-*.bin pieeprom.bin
sudo rpi-eeprom-config pieeprom.bin > bootconf.txt
- change BOOT_ORDER to be 0x21 instead of 0x1
sed -i s/0x1/0x12/g bootconf.txt
- apply the configuration change to the EEPROM image file
sudo rpi-eeprom-config --out pieeprom-netboot.bin --config bootconf.txt pieeprom.bin
- install the new EEPROM image and reboot
sudo rpi-eeprom-update -d -f ./pieeprom-netboot.bin
sudo reboot