[U-Boot] [PATCH 21/22] x86: ivybridge: Update microcode early in boot

[Bin Meng]

On Wed, Dec 31, 2014 at 2:45 PM, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Sun, Dec 28, 2014 at 10:20 AM, Simon Glass <sjg at chromium.org> wrote:
>> At present the normal update (which happens much later) does not work. This
>> seems to have something to do with the 'no eviction' mode in the CAR, or at
>> least moving the microcode update after that causes it not to work.
>>
>> For now, do an update early on so that it definitely works. Also refuse to
>> continue unless the microcode update check (later in boot) is successful.
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>
>>  arch/x86/cpu/ivybridge/car.S             | 14 ++++++++++++++
>>  arch/x86/cpu/ivybridge/cpu.c             |  2 +-
>>  arch/x86/cpu/ivybridge/microcode_intel.c |  9 +++++++--
>>  arch/x86/dts/link.dts                    |  3 ---
>>  4 files changed, 22 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/cpu/ivybridge/car.S b/arch/x86/cpu/ivybridge/car.S
>> index 6e7e1e4..95da087 100644
>> --- a/arch/x86/cpu/ivybridge/car.S
>> +++ b/arch/x86/cpu/ivybridge/car.S
>> @@ -45,6 +45,14 @@ car_init:
>>         movl    $0xFEE00300, %esi
>>         movl    %eax, (%esi)
>>
>> +       /* TODO: Load microcode later - the 'no eviction' mode breaks this */
>> +       movl    $0x79, %ecx
>
> Replace 0x79 to MSR_IA32_UCODE_WRITE from msr-index.h
>
>> +       xorl    %edx, %edx
>> +       movl    $_dt_ucode_base_size, %eax
>> +       movl    (%eax), %eax
>> +       addl    $0x30, %eax
>
> And here 0x30 to something like MICROCODE_HEADER_LEN.
>

I realized UCODE_HEADER_LEN might be better. At least shorter than
microcode :-), and is consistent with the MSR_IA32_UCODE_WRITE.

[snip]

Regards,
Bin