[SeaBIOS] (PAM stuff) reset doesn't work on OVMF + SeaBIOS CSM

[David Woodhouse]

On Thu, 2013-02-14 at 21:41 +0100, Laszlo Ersek wrote:
> Can we dumb down ^W^W generalize this code? :) Or maybe should qemu
> introduce a reset handler for PAMs?

In the UEFI+CSM model, I believe the handling of PAM stuff is left
*entirely* to the UEFI side and the CSM is supposed to be
hardware-agnostic. So actually bashing on the PAM registers from the CSM
side would be my last resort. It's why it's important to fix the
UmbStart/UmbEnd thing correctly, too.

Other people might have been happy to hack up something
machine-specific, given that they control both UEFI and CSM sides of it
and they're shipping their own proprietary version where nobody can see
what they're doing. But when the CSM spec is the interface between two
entirely *separate* projects (OVMF and SeaBIOS), I think it's important
that we *follow* the spec and don't have nasty hacks.

So, if real hardware would reset the PAMs on reset and avoid the need
for SeaBIOS to do so, I think we should be doing the same in qemu too.

Thanks for testing this, btw. Are you looking at suspend/resume too? :)

-- 
dwmw2

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