README: add doc for how to supply user specific compiler flags to Kbuild
Probably not all users are aware of this possibility, thus add a
pointer to the README. Also add a useful example.
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/README b/README
index b53ea7d..b055ae7 100644
--- a/README
+++ b/README
@@ -3719,6 +3719,11 @@
Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
variable.
+User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
+setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
+For example to treat all compiler warnings as errors:
+
+ make KCFLAGS=-Werror
Please be aware that the Makefiles assume you are using GNU make, so
for instance on NetBSD you might need to use "gmake" instead of