ASUS microcode updates - header format of cpucode.exe
Mathias Rufer
Based on the information provided by Martin and Carl Tao I was finally
able to write a document with the header format of the Asus microcode
updates for Intel PIII/Celeron CPUs.
Read it here (PDF format):
http://www.mrufer.ch/pc/asus_microcode.pdf
Feel free to link that document but don't forget to credit the two
persons mentioned above.
Greetings
Rufer
flaky
>Hello all
>
>Based on the information provided by Martin and Carl Tao I was finally
>able to write a document with the header format of the Asus microcode
>updates for Intel PIII/Celeron CPUs.
I'm not sure this is a good idea.
I tried to update my P2B-B bios with the latest Tualatin B4 stepping
microcode. It doesn't work. It is seemingly not possible to modify the
bios of this board in any way. Just adding the one MC block rendered the
machine non-booting. The same happened with a correctly modified EPA
image. I tried this several times using cbrom and awardmod just to be
sure.
If you need a microcode update DO NOT modify the bios if you can avoid
it. Instead the _safe_ method is to extract the MC block from a
different,newer bios by using the CTMC utility from c't magazine, then
flash add it to your bios which provides an API for this. Yes, every
BIOS has two reloadable MC blocks and a predefined, safe method to
update them. No need to tamper at all.
The 'official' tool to do this (pupdt6*.exe) is not available from Intel
for end-users (...)
Btw the Asus header format is really easy to understand. Your document
will only invite people who shouldn't be doing this anyway. I did my
modfications 100% correctly and it still left the machine dead.
And to those who are going to find this thread sooner or later, here's
how to revive a dead machine: Find the clear_cmos (clr_rtc or similar)
jumper on your board and short it momentarily. Then wait for at least 2
minutes for the condensators to unload. This is important. Then press
and hold the DEL or whatever key is used to enter BIOS setup already
BEFORE powering on. This will give you one last attempt to configure the
bios, boot into pure dos and reflash a good bios.
Mathias Rufer
> I'm not sure this is a good idea.
>
> I tried to update my P2B-B bios with the latest Tualatin B4 stepping
> microcode. It doesn't work. It is seemingly not possible to modify the
> bios of this board in any way. Just adding the one MC block rendered the
> machine non-booting. The same happened with a correctly modified EPA
> image. I tried this several times using cbrom and awardmod just to be
> sure.
>
Hello
It's true that this modification is unsuitable for unexperienced
users.
But tell me what could go wrong if the microcode image is bit
identical with an existing image? (I mean I did an image with exactly
the same files as the original and compared it --> identical)
It's very important to use the right cbrom version. And the microcode
may not be added but rather replaced in the BIOS (you probably did it
this way).
Anyway, thanks for the hint with the ct tool. I knew the tool but not
if it runs with the Asus boards.
Greetings
Rufer