config MCA_LEGACY bool "Legacy MCA API Support" depends on MCA help This compiles in support for the old slot based MCA API. If you have an unconverted MCA driver, you will need to say Y here. It is safe to say Y anyway. config MCA_PROC_FS bool "Support for the mca entry in /proc" depends on MCA_LEGACY && PROC_FS help If you want the old style /proc/mca directory in addition to the new style sysfs say Y here.