config PREP_RESIDUAL bool "Support for PReP Residual Data" depends on PPC_PREP help Some PReP systems have residual data passed to the kernel by the firmware. This allows detection of memory size, devices present and other useful pieces of information. Sometimes this information is not present or incorrect, in which case it could lead to the machine behaving incorrectly. If this happens, either disable PREP_RESIDUAL or pass the 'noresidual' option to the kernel. If you are running a PReP system, say Y here, otherwise say N. config PROC_PREPRESIDUAL bool "Support for reading of PReP Residual Data in /proc" depends on PREP_RESIDUAL && PROC_FS help Enabling this option will create a /proc/residual file which allows you to get at the residual data on PReP systems. You will need a tool (lsresidual) to parse it. If you aren't on a PReP system, you don't want this.