[coreboot] Fwd: SimNOW VGA int 1a

[ron minnich]

On Thu, Oct 16, 2008 at 2:52 PM, Carl-Daniel Hailfinger
<c-d.hailfinger.devel.2006 at gmx.net> wrote:

> If that's it, the solution is absolutely simple. And I mean totally simple.
> 1. Backup old content
> 2. Write ffffffff

at this point it is game over.
The code that does this is in rom.

> 3. Read back and save in a variable
> 4. Restore old content.
> Make sure no code blacked out by the decode is executed between 1 and 4
> and you're safe. If you're feeling paranoid, do it as inline asm. Make
> sure that short sequence is never ever run as XIP code in ROM (I can do
> that checking right now).
>
> What am I missing?
>

the big thing is that the problem code is a binary vga bios over which
we have zero control. :-(

ron