[LinuxBIOS] Intel refactoring and microcode updates

Corey Osgood corey.osgood at gmail.com
Fri Jan 11 03:34:28 CET 2008

Carl-Daniel Hailfinger wrote:
> On 11.01.2008 02:33, Corey Osgood wrote:
>> joe at smittys.pointclark.net wrote:
>>> Quoting Corey Osgood <corey.osgood at gmail.com>:
>>>> Do you mean the microcode files? If so, the microcode update looks like
>>>> this:
>>>> Header
>>>> Update Revision
>>>> Date
>>>> Processor Signature (CPU ID)
>>>> ...
>>>> So, the 4th entry in the update is always the CPU ID, and conveniently
>>>> it's always the last one on the first line. It also makes grepping for
>>>> them very easy, once you have the update broken down into smaller files.
>>>> This is documented *somewhere* in LB, but I can't find it at the moment.
>>>> It's also in the Intel architecture manual, volume 3a, table 9-6.
>>>> In the past we labeled some CPU IDs as to what CPUs they belonged to. In
>>>> truth, Intel uses the same CPU IDs for a variety of CPUs, for instance
>>>> in some cases Celeron, Pentium X, and Xeons all share a common ID, since
>>>> the core is still the same. So we can't really do that any more ;)
>>> Oh ok, that makes sense.
>>> Acked-by: Joseph Smith <joe at smittys.pointclark.net>
>> Thanks, Joe. Anyone else have anything to say? Honestly expected more
>> feedback, but if there are no objections I'll commit it tomorrow.
>> The other thing I forgot to mention was that all the data on CPU IDs
>> came from the existing code and this site:
>> http://processorfinder.intel.com. Some of them are a bit unclear on what
>> sockets they use, but if anything comes up wrong, we can easily correct it.
> Do you see any way to solve the "size problem" for sockets with too many
> different cores? It would also be interesting to find out if your work
> on stripping duplicate contents gives us new opportunities to reduce
> size even further.
> Regards,
> Carl-Daniel

I'm thinking lzma compression, it knocks the files down to about 1/3
their current size or smaller. But I hate to introduce lzma as a
requirement, especially just for this one task, and some distros don't
have lzma prepackaged. I have already removed all the duplicate updates,
so the only option is possibly eliminating more cores, for socket 604,
and for lga775 it's either breaking things down into smaller subsets
(pentium vs. core, as i mentioned before), or larger flash chips.

joe at smittys.pointclark.net wrote:
> Not sure what you mean? How many different cores could you put in even
> the most popular socket, three?
> Thanks - Joe 

LGA775 currently has 19 (and may have more I don't know about). Using
some rough math, I get a rounded-down size of 186KB (really is quite a
bit more) for its updates, and that would go into both normal and
fallback images.


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