In contrast to most firmware, like UEFI based or the BIOS, Linux is free software, has drivers for everything and is well known to the administrator. So why not use it in the firmware too? Some work has to be done though to fit it into the flash ROM chip and make it fast.
Due to increases in flash ROM chip sizes, it’s possible again to put the Linux kernel and an initrd there, and use Linux as a boot loader. In 2017 the LinuxBoot project joined the Linux Foundation, and several big companies backed it. This talk presents the project, the benefits and gives a short demonstration in conjunction with coreboot.
To achieve the goal, the Linux kernel should be adapted for the board to make it as small as possible. So, it’s back to building your own Linux kernel. Additionally, the boot time should not suffer, so methods on how to profile and to improve start-up time are presented.