Re: [Patch V3] EmulatorPkg: don't display the cpu current speed

["Jordan Justen" <jordan.l.justen@intel.com>]

On 2019-06-11 00:32:27, Zhiguang Liu wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1686
> 
> V3: I hope that changing the status of the mCpuSmbiosType4
>     wouldn't affect other features except showing CPU speed.
>         The value is zero in NT32Pkg.
> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Andrew Fish <afish@apple.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
> ---
>  EmulatorPkg/CpuRuntimeDxe/Cpu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/EmulatorPkg/CpuRuntimeDxe/Cpu.c b/EmulatorPkg/CpuRuntimeDxe/Cpu.c
> index 00e93016af..a5e19b4181 100644
> --- a/EmulatorPkg/CpuRuntimeDxe/Cpu.c
> +++ b/EmulatorPkg/CpuRuntimeDxe/Cpu.c
> @@ -104,7 +104,7 @@ SMBIOS_TABLE_TYPE4 mCpuSmbiosType4 = {
>    0,                      // ExternalClock;
>    0,                      // MaxSpeed;
>    0,                      // CurrentSpeed;
> -  0x41,                   // Status;
> +  0,                      // Status;

It looks like bit 6 means the process is populated, and bits[2:0]==1
means the CPU is enabled.

So, it looks like this change will make SMBIOS indicate the the
processor socket is not populated, and bit2[2:0]==0 means that the CPU
status is unknown.

I think the commit message for this patch should have been:

===

EmulatorPkg: Change SMBIOS processor to unpopulated

This change updates the SMBIOS processor information to indicate that
the processor is not populated, and that it's status is unknown.

With this change the processor speed will not be shown in setup.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1686

===

But, I'm not sure I agree we should make this change to fix this bug.
I'm not particularly concerned with this bug, but I wonder if perhaps
the MdeModulePkg should just suppress the item if the speed is 0.

Or, alternately, perhaps we can investigate some methods to attempt to
determine the processor speed. I guess for all OS's, it might be
difficult, but we probably could support finding the processor speed
under the most common environments.

-Jordan