[coreboot] Coreboot Picasso FSP questions

Hi,

I study in AMD AGESA v9 boot in the coreboot. 
So far, I boot to the FSP image failed as below log.
CBFS: Locating 'fspm.bin'
CBFS: 'fspm.bin' not found.
FSPM not available or failed to load!

And I google the related information, found the gerrit review information(https://review.coreboot.org/c/coreboot/+/34423/),
I want to query you how to make/create the FSP binary for AMD or FSP information to coreboot image.
Could you give me some instructions? Thanks.