On Wed, Aug 12, 2015 at 07:31:43AM +0900, Masahiro Yamada wrote:
The previous commit introduced a useful macro used in makefiles, in order to reference to different variables (CONFIG_... or CONFIG_SPL_...) depending on the build context.
Per-image config option control is a PITA in C sources, too. Here are some macros useful in C/CPP expressions.
CONFIG_IS_ENABLED(FOO) can be used as a shorthand for
(!defined(CONFIG_SPL_BUILD) && defined(CONFIG_FOO)) || \ (defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_FOO))
For example, it is useful to describe C code as follows,
#if CONFIG_IS_ENABLED(OF_CONTROL) (device tree code) #else (board file code) #endif
The ifdef conditional above is switched by CONFIG_OF_CONTROL during the U-Boot proper building (CONFIG_SPL_BUILD is not defined), and by CONFIG_SPL_OF_CONTROL during SPL building (CONFIG_SPL_BUILD is defined).
The macro can be used in C context as well, so you can also write the equivalent code as follows:
if (CONFIG_IS_ENABLED(OF_CONTROL)) { (device tree code) } else { (board file code) }
Another useful macro is CONFIG_VALUE(). CONFIG_VALUE(FOO) is expanded into CONFIG_FOO if CONFIG_SPL_BUILD is undefined, and into CONFIG_SPL_FOO if CONFIG_SPL_BUILD is defined.
You can write as follows:
text_base = CONFIG_VALUE(TEXT_BASE);
instead of:
#ifdef CONFIG_SPL_BUILD text_base = CONFIG_SPL_TEXT_BASE; #else text_base = CONFIG_TEXT_BASE; #endif
This commit also adds slight hacking on fixdep so that it can output a correct list of fixed dependencies.
If the fixdep finds CONFIG_IS_ENABLED(FOO) in a source file, we want $(wildcard include/config/foo.h) in the U-boot proper building context, while we want $(wildcard include/config/spl/foo.h) in the SPL build context.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Reviewed-by: Tom Rini trini@konsulko.com Reviewed-by: Simon Glass sjg@chromium.org
Applied to u-boot/master, thanks!