If you would like to see an actually "interesting" boot, I recommend checking out how Raspberry Pi's boot.
replyIt is a unique monstrosity that boots from the video / GPU core instead of one of the ARM cores. It has an arcane undocumented architecture.
When I realized that, after buying my first Rpi (2B), that was the last Rpi I ever bought. :)
replyThankfully, pretty much everyone else just uses U-Boot.
Maybe not linux specifically, but POST requires a video device software (BIOS Option ROM or UEFI GOP Drivers) of some sort does it not? That's been my experience with all PCs for 30 years. But maybe there are cases where it doesn't?
replyedit: Apparently it's a desktop motherboard firmware thing. Ubiquitous but not technically a requirement for POSTing a computer.
I've found AM4/AM5 boards will still boot Linux without a discrete or integrated GPU, running a GPUless CPU, not an APU.
replyIt was sorta required by IBM PC compatibles, but is not required by UEFI which supports serial console (or other interfaces).
replyIBM PC assumed existence of graphic output and sometimes Option ROMs did really too crazy things with it, I still have shivers when I hear "intel raid card" because of that one with possibly Win3.x in ROM...
Soekris (rip) had an x86 network device. Four 10/100s and the disk was a CF. Could only serial console that thing - or SSH once it's running. Best router I ever had.
replyAlso, in 2000 when Windows crashed you could get a serial debugger. Wonder if they still do that?
People still need to do driver ddvelopement. So you can still set up a Windows PC to expose kernel debug interface over serial port: https://learn.microsoft.com/en-us/windows-hardware/drivers/d...
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