it’s so happy that, filo finally can load libpayload kconfig. i deleted the first line of libpayload Config.in which is “mainmenu”, it still work even if libpayload build itself alone. After this, filo can easy load libpayload kconfig by adding “source ../libpayload/Config.in”. The variable is also blocked me a while for each variable is defined by quotation mark. the makefile should remove these quotation mark before using them, i learned that from coreboot makefile.
the xcompile things of libpayload has already resolved, i found that filo have the same problem which seem the scripts are almostly the same with libpayload, they are need to use the correct directory of coreboot, not themselves.
the problem now is the kconfig command “source” is used to read specified configuration file, this file is always parsed which means that it is parsed at the first beginning, i can not make it get the variable from the forward defined lines. it can only read from ../libpayload. i am thinking if we put filo under coreboot/payloads/, then the path is permanent. We did not need to change this path.