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 arch 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>
Introducing CMake is an important step in a larger effort to make
Zephyr easy to use for application developers working on different
platforms with different development environment needs.
Simplified, this change retains Kconfig as-is, and replaces all
Makefiles with CMakeLists.txt. The DSL-like Make language that KBuild
offers is replaced by a set of CMake extentions. These extentions have
either provided simple one-to-one translations of KBuild features or
introduced new concepts that replace KBuild concepts.
This is a breaking change for existing test infrastructure and build
scripts that are maintained out-of-tree. But for FW itself, no porting
should be necessary.
For users that just want to continue their work with minimal
disruption the following should suffice:
Install CMake 3.8.2+
Port any out-of-tree Makefiles to CMake.
Learn the absolute minimum about the new command line interface:
$ cd samples/hello_world
$ mkdir build && cd build
$ cmake -DBOARD=nrf52_pca10040 ..
$ cd build
$ make
PR: zephyrproject-rtos#4692
docs: http://docs.zephyrproject.org/getting_started/getting_started.html
Signed-off-by: Sebastian Boe <sebastian.boe@nordicsemi.no>
Adithya Baglody