Proper way to enable port access tracing with current xserver

[Alex Deucher]

On Thu, Jan 15, 2009 at 3:10 PM, Alex Villací­s Lasso
<a_villacis at palosanto.com> wrote:
> I am trying to enable I/O port tracing on current xserver head in my home
> machine (Linux 2.6.28 on x86 Pentium 4 32-bits, ProSavageDDR-K as primary
> card, Oak OTI64111 as secondary card) in order to learn about the register
> initialization for the video BIOS of both the Savage and the Oak chipsets:
>
> * For savage, I want to eventually see the POST port accesses as they occur
> in VESA, so that the current driver can do the same port enabling on the
> case of a savage as secondary card. Currently, the xorg driver can
> initialize a secondary savage without BIOS (but see below for caveat), but
> the colors are washed out and horrible artifacts appear on any attempt to
> accelerate operations. Same issue happens with the savagefb kernel
> framebuffer driver.
> * For oak, I want to peek at the register initialization for mode switching
> in VESA, in order to have better understanding towards writing a driver for
> the chipset.

http://people.freedesktop.org/~airlied/xresprobe-mjg59-0.4.21.tar.gz

This will dump io accesses when you execute bios code using the
included x86 emulator.

Alex