help for Radeon BIOS Editor, reversing the bios signature

[Dario Napole]

El 20/06/11 14:32, Corbin Simpson escribió:
> On Sun, Jun 19, 2011 at 1:03 PM, Dario Napole<darionapole at gmail.com>  wrote:
>> hi, and sorry for asking here, i'm not sure this is the right place but it
>> was the only one that i know that has highly experienced programers and that
>> also reverse engineer drivers. (btw first time using a mailing list so sorry
>> if i missed something)
>>
>> I'm just going the ask if anyone has some free time and would like to give
>> it a try and help BAGZZlash at Tech Power Up, because nor i nor him does
>> know enought to do it.
>> The problem is that RBE is able to edit the bios, but AMD introduced some
>> kind of signature check for the HD 6000 series bios and if it doesn't match
>> it rolls back the configuration to the original ones. This is bothersome
>> because you can't even change the fan curve if you dont like your 6950
>> working at 90ºC just to keep it quite (the VRM can even reach 110ºC) .
>> This can also be quite usefull if you use the gpu for extensive tasks with
>> openGL, which as the fan curve is prepared for "gaming", could very much end
>> up burning the card as would happen with furmark if you dont set the fan at
>> 100%.
>>
>> If anyone could reverse enginering the algoritm so he can add it to RBE, i
>> would be very gratefull
>> sorry if this wasn't the  right place to ask for help
>>
>> the topic in the forum is this one (i'm laharl2k)
>> http://www.techpowerup.com/forums/showthread.php?t=147647
>>
>> thanks in advance for any help you could give him
> We don't encourage or support flashing video BIOS. The Coreboot team
> has tools for modifying Radeon BIOS which might be useful, although I
> don't know if they support HD 6xxx cards yet.
>
> As an aside, I'm relatively sure that Furmark cheats somehow; I
> emailed the author a while back asking about it and received no
> response. I noticed that Furmark somehow convinces cards to change
> their fan speeds.
>

about that tool, i searched a little and found testbios (for programing 
video bioses) but the problem wasn't about modifying the vga bios, the 
problem lies in the driver (catalyst/fglrx), when it loads if the bios 
signature doesn't match with the rest of the vga bios then the driver 
sets the card to the default settings.
Let's say you edit the bios to keep the fan at 100%, u flash it, and 
restart. At first it works fine, the fan stays at 100% until fglrx 
loads, the it backs to the original curve. The same with catalyst.

And with the furmark thing, i haven't had any problem like that, with 
neither my HD4670 nor my HD6950, you should check the fan curve with rbe 
and see if it does what it says with furmark, mines always did what they 
said in the bios.