[M] Change in coreboot[main]: mb/google/brox: Fix booting to kernel without battery

[Sowmya Aralguppe (Code Review)]

Attention is currently required from: Ashish Kumar Mishra, Caveh Jalali, Dinesh Gehlot, Eric Herrmann, Forest Mittelberg, Jayvik Desai, Kapil Porwal, Karthik Ramasubramanian, Keith Short, Krishna P Bhat D, Nick Vaccaro, Paul Menzel, Rishika Raj, Ronak Kanabar, Shelley Chen, Sowmya Aralguppe, Subrata Banik.

Sowmya Aralguppe has posted comments on this change by Sowmya Aralguppe. ( https://review.coreboot.org/c/coreboot/+/83752?usp=email )

Change subject: mb/google/brox: Fix booting to kernel without battery
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Patch Set 19:

(1 comment)

File src/mainboard/google/brox/romstage.c:

https://review.coreboot.org/c/coreboot/+/83752/comment/09170686_22d4ca66?usp... :
PS19, Line 27: MAX_NONTURBO_PERFORMANCE
> Please raise a partner issue regarding this if Boot needs to be always in HFM because by default Boo […]

at which stage, you are seeing "CPU brown out" ? romstage or ramstage ? I assume you are seeing Bootfrequency=2?
-It happens in  ramstage ( FspMultiPhaseSiInit)
who is setting TurboModeDisable ? I assume croeboot can always override this.
- FSP - in function  VOID SetBootFrequency (
  IN SI_POLICY_PPI           *SiPolicyPpi
  )
If bootfreq is set 2 - I believe the boot will start in HPM and then switch to turbo mode (by looking at the code and logs) ..If this is not the expected behavior then we should follow it up a separate bug