How can I pass command line options to secondary payload?

[Dustin Brazeau]

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.