Using find_package to locate Zephyr.
Old behavior was to use $ENV{ZEPHYR_BASE} for inclusion of boiler plate
code.
Whenever an automatic run of CMake happend by the build system / IDE
then it was required that ZEPHYR_BASE was defined.
Using ZEPHYR_BASE only to locate the Zephyr package allows CMake to
cache the base variable and thus allowing subsequent invocation even
if ZEPHYR_BASE is not set in the environment.
It also removes the risk of strange build results if a user switchs
between different Zephyr based project folders and forgetting to reset
ZEPHYR_BASE before running ninja / make.
Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>
Add a sample that demonstrates (and tests) that custom drivers can be
maintained outside of Zephyr.
The sample is fairly minimal with few dependencies and should
therefore be very portable. It also includes a sample.yaml that should
ensure that it does not regress.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
