> Most regular BIOSes contains IPv4 for PXE anyway. Indeed. But that's UDP only, not TCP which is a lot more complex. UEFI contains TCP as well (IIRC recent ve

> Most regular BIOSes contains IPv4 for PXE anyway. Indeed. But that's UDP only, not TCP which is a lot more complex. UEFI contains TCP as well (IIRC recent versions of UEFI support boot over HTTP, similar to iPXE). > UEFI just allows you to do PXE a little more cleanly directly from firmware without needing a disk to bootstrap the process with other stuff like iPXE. That's correct. OTOH when your firmware + bootloader stuff requires a TCP/IP stack, HTTP, support for booting from all kinds of software RAID setups, filesystem support in order to be able to find and load the kernel, and whatnot, replacing all of that with a minimal Linux kernel + userspace doesn't sound so crazy anymore.