[coreboot] Re: Call to FSP_FSP_INIT never returns back

[Naveen Chaudhary]

Hi,

I found answers to part of my question that the .bsf file defines all the default values which can be opened in a normal text editor. In fact, the Windows based GUI BCT tool also shows all the default values using this file (till now I was using command line BCT unaware of the other side).

Still I couldn't find a way to initialize DIMMs. There is only one field called MemDdrMemoryType which looks relevant but after this will the FSP automatically read SPD from the RAM sticks? Will setting MemDownEnable=0 will autmatically make FSP look for RAM sticks and read SPD on its own? (MemDownCh*Dimm*SpdPtr is related to soldered RAM and can't be used).

Can someone please confirm this last thing. Thanks.

Regards,
Naveen
________________________________
From: Naveen Chaudhary 
Sent: Wednesday, October 23, 2019 9:02 PM
To: [e-mail] ; [e-mail] 
Subject: Re: Call to FSP_FSP_INIT never returns back

Hi,

The crux of the problem is that I am currently seeing a hack immediately after FSP_FSP_INIT is called and the next function ChipsetFspReturnPoint( ) never gets called, which indicates its hanged in FSP. Now how can I debug the situation as what's going wrong?

I was reading the BroadwellDE FSP Integration guide and there is this paragraph :

SerialPortType
Debug serial port resource type. Select 'None' to have FSP generate no output. Select
'I/O' to have FSP generate output via a legacy I/O output (i.e. 0x2f8/0x3f8).

Now again there is no discussion as what integer value does I/O is represented with? Is it 0x1 ? 0x2 ? We don't know. There is no enum in the FSP headers as well. So I gave up on the FSP log part, and assumed it could be because of missing RAM settings. Since I disabled MemDownEnable, I should be passing UPD for DIMM slots. But again there is no field I could find in the UPD_DATA_REGION which seems related to be accepting DIMM configurations.

Also referring the code in coreboot, if MEMDOWN is disabled, it simply sets MemDownEnable=0 and then directly calls FSP_FSP_INIT with no reading of DIMM SPD or hardcoded values. This left me clueless as how coreboot initializes DIMM memory for BroadwellDE ? Is it unimplemented or am I missing something?

I request the community to please help and guide.

Regards,
Naveen
________________________________
From: [e-mail] 
Sent: Wednesday, October 23, 2019 10:49 AM
To: Naveen Chaudhary ; [e-mail] 
Subject: AW: Call to FSP_FSP_INIT never returns back

Hi Naveen.

I am not sure that FSP supports mixed setup with both memory down and DIMMs at the same time. At least there is just one UPD parameter telling that you either have DIMM or memory down enabled (MemDownEnable).
So I haven't figured out how to tell FSP which channel is memory down and which is using normal DIMMs. That might be already your problem.
You can try to just use the channel that is of the same type and disable the other one (e.g. just use the DIMM and let FSP do its work) to see if that might bring a bit more light into the darkness of FSP.

For the default values of FSP BCT should be able to help you. What are the issues you are running in?
You need to open your binary blob (the .fd file) with BCT and then all the values should be loaded.

Werner

Von: Naveen Chaudhary 
Gesendet: Dienstag, 22. Oktober 2019 20:46
An: [e-mail]
Betreff: [coreboot] Call to FSP_FSP_INIT never returns back

Hi All,

Need some guidance. Please read.
I am porting coreboot for a "Broadwell D 1519" based motherboard which has both Memory Down as well as 2 DIMM slots. Hence, I built an image for Facebook Watson since its the closest mainboard with no code changes. The call from FSP_FSP_INIT never returns to the ChipsetFspReturnPoint( ).  Probably something crashed inside the FSP or something else.

This is possibly happening because I have passed no information regarding the RAM chips (down or DIMM) from romstage_fsp_rt_buffer_callback(). I have following 2 questions :
1. How can I see the default values for FSP UDP structure, so that I get to know what I need to modify? BCT tool does not dump that info.
2. In intel/soc/fsp_broadwell/ , the save_dimm_info() is done after FSP_FSP_INIT returns. Shouldn't the SPD details have been fetched before and passed to the FSP_FSP_INIT, as it is this API that handles the memory init.

Regards,
Naveen