3 Jan
2024
3 Jan
'24
10:30 a.m.
On Tue, Jan 02, 2024 at 08:57:34PM -0700, Warner Losh wrote:
Indeed. I got to deal with all of that, and more. I have finished writing
LinuxBoot support for FreeBSD. The normal kexec-tools, u-root, etc aren't
sufficient for FreeBSD because FreeBSD's kernel expects the boot loader
to setup a number of meta-data items that go with the kernel that include
all the information about the system that the kernel simply can't get once
you've entered long mode...
Even with LinuxBoot, you are booting with UEFI, albeit with a much small
much smaller UEFI.
Yeah, one of the older names of LinuxBoot was NERF (Non-Extensible
Reduced Firmware). I was confusing LinuxBoot with coreboot, which is
used on all ChromeOS devices after 2012, and which completely doesn't
use any magic binary blobs supplied by the mainbord vendor. The
tradeoff is that coreboot only supports a very restricted set of
hardware, since it has to do all of the things that are "normally"
done by the vendor's binary blobs to initialize the hardware devices,
etc. This only works if you have very tight control over hardware,
and you have enough influence that you can lean on the mainboard
vendors to allow the low-level programming details of their devices to
be released in open source code which that can be independently
verified and digitally signed by the OS vendor (such as Google in the
case of ChromeOS).
Many hyper-scale cloud companies will tend to use coreboot or related
software instead of UEFI. A public/published example of this is
Facebook's Open Compute Project.
It *is* nice not to have to deal with UEFI at all, if you're lucky
enough to be able to use hardware where it's not necessary.... Of
course you won't be able to run Windows on those systems, but some
would consider that a feature. :-)
- Ted