[SeaBIOS] [Qemu-devel] SeaBIOS booting time optimization

[Steve Douthit]

On 11/20/18 10:55 AM, Kevin O'Connor wrote:
> On Mon, Nov 19, 2018 at 07:38:39PM +0100, Stefano Garzarella wrote:
>> just an update, I enabled the debug prints and I saw two timeouts fired
>> with a lot
>> of time lost (~780ms between "init timer" and "Scan for VGA ..."),
>> putting other prints I discovered that a lot of time is spent in the
>> tpm_setup(),
>> during the probe of the 2 TPM devices:
>>
>> 00.548869 init timer
>> 00.549677 ./src/post.c:157 platform_hardware_setup
>> 00.550182 ./src/hw/tpm_drivers.c:579 tpmhw_probe
>> 01.300833 WARNING - Timeout at wait_reg8:81!
>> 01.301388 ./src/hw/tpm_drivers.c:579 tpmhw_probe
>> 01.331843 WARNING - Timeout at wait_reg8:81!
>> 01.332316 ./src/post.c:160 platform_hardware_setup
>> 01.333358 Scan for VGA option rom
> 
> FYI, this was raised a few months ago - see:
> 
> https://mail.coreboot.org/pipermail/seabios/2018-March/012186.html
> 
> IIRC, it should be possible to verify the TPM device is present before
> trying to wait for it.

We could skip probing entirely if there's no TCPA or TPM2 ACPI tables.
There'd need to be some option to force probing in the case of
missing/broken ACPI configurations.

> -Kevin
>