kconfig-language: add to hints

Explain a little about kconfig symbol dependencies and symbol
existence given optional kconfig language scenarios.
Yes, I was bitten by this.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
This commit is contained in:
Randy Dunlap 2011-04-28 10:58:52 -07:00 committed by Michal Marek
parent df835c2e7f
commit 64b81ed7fb

View File

@ -389,3 +389,25 @@ config FOO
limits FOO to module (=m) or disabled (=n).
Kconfig symbol existence
~~~~~~~~~~~~~~~~~~~~~~~~
The following two methods produce the same kconfig symbol dependencies
but differ greatly in kconfig symbol existence (production) in the
generated config file.
case 1:
config FOO
tristate "about foo"
depends on BAR
vs. case 2:
if BAR
config FOO
tristate "about foo"
endif
In case 1, the symbol FOO will always exist in the config file (given
no other dependencies). In case 2, the symbol FOO will only exist in
the config file if BAR is enabled.