Proper way to enable port access tracing with current xserver

[Alex Villací­s Lasso]

Alex Deucher escribió:
> 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
>
>   
 From a quick skim over the contents of the file, I see an x86emu 
directory. I think I have seen a directory with that name in the xserver 
sources. Is it safe to switch to x86emu on an x86 32-bits in the xserver 
source? Or do I have to keep in mind some special consideration?

-- 
perl -e '$x=2.4;print sprintf("%.0f + %.0f = %.0f\n",$x,$x,$x+$x);'