as a followup to my earlier post, one of my other linux kernel cleanup scripts was to identify "CONFIG_*" variables that *were* being tested in the source somewhere, but for which there was no definition for that variable in any Kconfig file.
for example, if there exists a line:
#if defined(CONFIG_RDAY)
then one should expect some Kconfig file to contain the definition:
config RDAY ... blah blah ...
sadly, that doesn't work so well with u-boot given the plethora of CONFIG_* variables that are simply hard-coded in header files, rather than being defined in any Kconfig file.
still, there seems to be a ton of that stuff; for example:
$ grep -r CONFIG_I2CFAST * common/board_r.c:#if defined(CONFIG_I2CFAST) common/board_r.c:#endif /* CONFIG_I2CFAST */ README: CONFIG_I2CFAST (PPC405GP|PPC405EP only) scripts/config_whitelist.txt:CONFIG_I2CFAST $
so there we have a CONFIG variable that is clearly being tested, but does not seem to be defined *anywhere*, even hard-coded in a header file. however, since it exists, it ends up in the whitelist file.
another short example:
$ grep -r MTD_UBI_BLOCK * drivers/mtd/ubi/ubi.h:#ifdef CONFIG_MTD_UBI_BLOCK include/ubi_uboot.h:#undef CONFIG_MTD_UBI_BLOCK scripts/config_whitelist.txt:CONFIG_MTD_UBI_BLOCK $
anyway, there's plenty of that sort of thing scattered through the code base.
rday