I am booting SeaBIOS as a payload of coreboot. I am then booting memtest86 as a secondary payload from SeaBIOS. It looks like memtest86 support command line options, but I can't figure out how to pass a command line to a secondary payload from SeaBIOS. Looks like it is somehow related to the multiboot option in SeaBIOS, which I have tried enabling, but I still can't figure out how add and pass a command line to a payload ran from SeaBIOS.