zephyr/drivers/i2s/CMakeLists.txt

zephyr_library()

zephyr_library_sources_ifdef(CONFIG_I2S_SAM_SSC		i2s_sam_ssc.c)
zephyr_library_sources_ifdef(CONFIG_I2S_CAVS		i2s_cavs.c)
drivers: Cmake: Add __ZEPHYR_SUPERVISOR__ macro for driver files. Normally a syscall would check the current privilege level and then decide to go to _impl_<syscall> directly or go through a _handler_<syscall>. __ZEPHYR_SUPERVISOR__ is a compiler optimization flag which will make all the system calls from the driver files directly link to the _impl_<syscall>. Thereby reducing the overhead of checking the privileges. In the previous implementation all the source files would be compiled by zephyr_source() rule. This means that zephyr_* is a catchall CMake library for source files that can be built purely with the include paths, defines, and other compiler flags that all zephyr source files uses. This states that adding one extra compiler flag for only one complete directory would fail. This limitation can be overcome by using zephyr_libray* APIs. This creates a library for the required directories and it also supports directory level properties. Hence we use zephyr_library* to create a new library with macro _ZEPHYR_SUPERVISOR_ for the optimization. Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com> 2018-03-28 18:06:12 +08:00			`zephyr_library()`

			`zephyr_library_sources_ifdef(CONFIG_I2S_SAM_SSC i2s_sam_ssc.c)`
			`zephyr_library_sources_ifdef(CONFIG_I2S_CAVS i2s_cavs.c)`