https://ru.wikipedia.org/wiki/Das_U-Boot

https://opencomputeproject.github.io/onie/design-spec/uboot_boot_loader.html

https://doc.s-terra.ru/rh_output/4.2/Gate_ESR/output/mergedProjects/Appendix/%D0%9A%D0%BE%D0%BC%D0%B0%D0%BD%D0%B4%D1%8B_U-Boot.htm
https://hub.digi.com/dp/path=/support/asset/u-boot-reference-manual/

https://www.youtube.com/watch?v=INWghYZH3hI

https://habr.com/ru/articles/585432/
https://habr.com/ru/sandbox/132293/