[U-Boot] [PATCH v2 15/27] x86: Integrate Tunnel Creek processor microcode

[Bin Meng]

Hi Simon,

On Wed, Dec 10, 2014 at 2:09 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 9 December 2014 at 07:50, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Integrate the processor microcode version 1.05 for Tunnel Creek,
>> CPUID device 20661h.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>> Changes in v2: None
>
> We are going to end up with microcode both in the device tree and in
> an assembler include file.
>
> This seems unfortunate. I wonder if we can always put it in the device
> tree, but then optionally also compile it into the image using a
> symbol (as we do in dts/Makefile for CONFIG_OF_EMBED). This could be
> done with fdtget to read the binary output of the property perhaps. I
> haven't looked at it in detail though.
>

This will do for the embedded case, but it won't help for the separate dtb case.

> Maybe this is too clumsy but it would be good to have it in one
> format. Or maybe we should have a tool which can generate either
> format.

I don't think we are able to parse device tree in that early phase
(before car_init), to get the microcode content from dtb. I know in
some Intel processors, the microcode update are required before CAR
initialization, as without the microcode update, the CAR
initialization will fail.

Regards,
Bin