Re: arch/i386/boot rewrite, and all the hard-coded video cards

Eric W. Biederman
2007-05-01T03:06:38Z

Andi Kleen <ak@suse.de> writes:

>> Not that the x86 BIOS is bad. It is nearly a marvel in it's simplicity
>> and ubiquitousness,
>
> Simplicity? That must be why x86 motherbords are shipping with (compressed)
> 8MB BIOS flash chips now.

Those would be 8 megabit chips, and those would be server motherboards
you are looking. Most likely the ones that are starting to think ahead
to EFI support.

There are thread jobs the firmware on a PC does.
- Configure the hardware to look like a PC.
What with memory controller setup and the like that is the hard
part and the bulk of the work.

Since this is written quickly and in assembler it has likely descended
into spaghetti by now.

- Whatever ACPI does. suspend/resume and etc.

- Provide a subroutine library for boot loaders.
That subroutine library is what gets exposed.

Now if you compare what it takes to implement the PC BIOS interface
the "subroutine library for bootloaders" with EFI, or open firmware
or a real OS you will quickly see how very small and simple it is. It
isn't a beautiful interface but it is short and to the point.

Eric