yeah it’s goofy, you can embed grub in coreboot cbfs and load straight into it, skipping the bios/uefi stage. it’s a bit difficult to set up (and you need coreboot supported hardware) but when you get it working the boot times become really quick
i just realised though that you can embed Linux into cbfs as well, does that then mean that Linux could be my kernel and firmware at the same time?
efivars are made read only by the kernel. That firmware bug (!) was worked around in the kernel years ago.
https://github.com/torvalds/linux/blob/master/Documentation/filesystems/efivarfs.rst
Specifically in 2016: https://github.com/torvalds/linux/commit/ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879
uefi is cringe anyway, reject uefi and return to grub in the system firmware
Firmware is one step before.
BIOS, UEFI, coreboot, or whatever weird code runs on a Raspberry Pi’s GPU to load your system, those are firmwares.
The firmware is what starts your bootloader; grub, BOOTMGR, u-boot, etc
even if my grub is in the system eeprom?
Oh I’ve never heard of such a setup. But that does muddy the lines a bit, I can see the argument for calling it part of firmware then.
yeah it’s goofy, you can embed grub in coreboot cbfs and load straight into it, skipping the bios/uefi stage. it’s a bit difficult to set up (and you need coreboot supported hardware) but when you get it working the boot times become really quick
i just realised though that you can embed Linux into cbfs as well, does that then mean that Linux could be my kernel and firmware at the same time?
Wow very cool. Thanks for that link, I had no idea coreboot was so flexible!
Why would someone do that? *keeps reading*
Now I almost want to try it out.