Re: Brainy: bug in x86/cpu_ucode_intel.c

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

Le 03/10/2015 18:19, Jean-Yves Migeon a écrit :
> Regarding the code, I am almost sure that the roundup2() is a
> requirement for microcode update for Intel x86 CPU. I suppose it
> requires a 16-byte aligned address for the blob hence the call to
> roundup2().

(answering to myself)

The Intel developer manual states that:

"""
[...] the microcode update must be aligned on a 16-byte boundary and the
size of the microcode update must be 1-KByte granular.
"""

That pretty much explains all.

(see page 9-34,
http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-system-programming-manual-325384.pdf)

-- 
Jean-Yves Migeon