3 ms·

It just is that complicated to bring up all the pieces of hardware in a timely manner and with the right configuration. Not to mention if you want to let user c

It just is that complicated to bring up all the pieces of hardware in a timely manner and with the right configuration. Not to mention if you want to let user configure things. Just look at say DRAM init: https://www.systemverilog.io/design/ddr4-initialization-and-calibration/ https://www.systemverilog.io/design/ddr4-initialization-and-... Of course you're gonna give that hard task to a memory controller, but then you have to initialise that. This goes on for all the subsystems, with complex interactions and features, all of which need handling. It's not a single microcontroller you're powering on, even if it were, those too require a bunch of initialisation code to function properly.

temac 3y ago
DRAM init as little to do with UEFI or BIOS and Intel probably ships x86 components for more exotic or even allow custom bootloaders. At least at a time they did. I don't know the current situation but when I played with all of that, I saw one of their "Memory Reference Code" in particular the parts in charge of calibration of the memory controller timing, and that was a quite short piece of x86 assembly completely independent from the UEFI architecture insanities. Well because it was written in assembly it had an obvious bug, but that's another story.