Proper way to enable port access tracing with current xserver

[Alex Deucher]

On Thu, Jan 15, 2009 at 4:53 PM, Alex Villací­s Lasso
<a_villacis at palosanto.com> wrote:
> 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?

We already do.  the xserver uses x86emu by default now for x86.

Alex