[coreboot] building a coreboot (and 100% free software) compatible box

Denis 'GNUtoo' Carikli GNUtoo at no-log.org
Thu Feb 7 20:52:47 CET 2013


On Thu, 07 Feb 2013 10:52:16 +0100
Rudolf Marek <r.marek at assembler.cz> wrote:
> >> 5) ATOM tables - you can interpret them via kernel driver
> 
> This is part of VGA ROM bios. You dont need to run vga rombios,
> radeon driver in kernel can do GPU POST. But you would have to check
> if the bytecode does not break the in kernel interpreter.
on the radeon of the M4A785T-M (01:05.0 VGA compatible controller:
Advanced Micro Devices [AMD] nee ATI RS880 [Radeon HD 4200]) it can:
some time ago I commented the VGA option rom running but kept it in
memory and it worked(the linux kernel initialized the card). it can
also work without the firmware but has no 3D acceleration nor video
acceleration(XV).

On the i915 it can also initialize the display in the linux kernel
without even the option rom in memory, the drawback is that the display
backlight is at its maximum and can't be ajusted anymore out of the box.
the i915 doesn't have a firmware, at least it seems(since it works with
trisquel and parabola).

I didn't try without the nvidia option rom yet...I really should.
The nvidia card even has 3D acceleration with the free
firmware.
> > Are you aware of any viable designs to do this?
> 
> Not sure, most likely opencores OpenRISC, but no idea about
> performance. There may be some ASIC at the end in the future.
There are some free software code that implements CPUs:
 * I heard that some sparcs cpus had some code available
 * I heard about milkymist which is a board with a latice32 cpu, but it
   seem to lack an MMU.
 * I heard about other CPUs like the LEON ones.
But their speed is limited...

you to care about high security, maybe he also needs to add
one requirement: locked SMM/SMI.

PS: I also want 100% free software coreboot(and the rest too, such as
my GNU/Linux distributions(I run trisquel and parabola depending on the
computer) etc...).

The main issue I have is the VGA option roms, for instance when I
travel I need to have the display inited during grub or even for the
press F12 of seaBIOS...

I've never succedded at making i915tool compile...
so maybe I should compile a tiny kernel with a tiny initramfs with
something like kexecboot.
Fitting it in the 2M of my x60 flash chip will be hard...

Denis.



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