[Lichtso]

For those who are interested in running your software on AArch64 hardware directly, without any additional firmware or operating system in between, I've developed a boot loader and tool chain to test and execute unikernels on a Pine64:

https://github.com/Lichtso/UnikernelExperiments

[lgeek]

Hmm, what are the advantages of using this bootloader over U-Boot? Or is it simply that U-Boot doesn't support Ethernet or some other peripherals on the A64 SoC?

[Lichtso]

On one hand it is very light weight: less than 4k LOC and 16 kB executable (which fits completely in the first stage of SRAM), so it is easier to grasp compared to U-Boot: https://github.com/trini/u-boot/search?q=sunxi&type=Code

On the other hand, it has different goals and is just meant to load a blob of instructions over ethernet (faster evaluation cycle) not an entire Linux kernel with all the POSIX / UNIX stuff from SD. So you have far more control but are also on a lower level, somewhat like developing for a more powerful Arduino.