[U-Boot] [PATCH v2 5/6] x86: Correct problems in the microcode loading

[Simon Glass]

Hi Bin,

On 16 December 2014 at 02:41, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Tue, Dec 16, 2014 at 1:02 PM, Simon Glass <sjg at chromium.org> wrote:
>> There are several problems in the code. The device tree decode is incorrect
>> in ways that are masked due to a matching bug. Both are fixed. Also
>> microcode_read_rev() should be inline and called before the microcode is
>> written.
>>
>> Note: microcode writing does not work correctly on ivybridge for me. Further
>> work is needed to resolve this. But this patch tidies up the existing code
>> so that will be easier.
>
> Yep, I noticed that with the new microcode.dtsi generated from the
> microcode tool, the endianness is different from previous ivybridge
> one. I think the new one is correct due to dts is using big-endian
> while IA processor is little-endian. I just wonder why previous dtsi
> could work on ivybridge? And now since we are using little-endian so
> we should decode dts using little-endian too. Is this endianness issue
> that causes the microcode writing does not work on ivybridge?

I think what happened is that I originally tested an early version of
the code (perhaps before device tree), but because the error handling
was broken I did not notice when it started failing, perhaps due to
something unrelated. I'll get back to looking at it again sometime but
for now I'm a bit stuck.

[snip]

Regards,
Simon