Hooking in external drivers

kernel.patch

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 84deadfc5..e137c867b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -293,6 +293,9 @@ add_subdirectory(misc)
 include(misc/generated/CMakeLists.txt)
 add_subdirectory(boards)
 add_subdirectory(ext)
+if(CONFIG_EXTERNAL_KERNEL_SYSTEMS)
+  add_subdirectory(${CONFIG_EXTERNAL_KERNEL_SYSTEMS} ${APPLICATION_BINARY_DIR}/external_kernel_systems)
+endif()
 add_subdirectory(subsys)
 add_subdirectory(arch)
 add_subdirectory(drivers)
diff --git a/misc/Kconfig b/misc/Kconfig
index 9fbb53e46..2489fe329 100644
--- a/misc/Kconfig
+++ b/misc/Kconfig
@@ -147,6 +147,11 @@ config TOOLCHAIN_VARIANT
 	  For optimized compilers with reduced features, specify the name
 	  of the variant.
 
+config EXTERNAL_KERNEL_SYSTEMS
+	string "external kernel components"
+	help
+	  TODO
+
 endmenu
 
 menu "Build Options"
diff --git a/samples/hello_world/prj.conf b/samples/hello_world/prj.conf
index b2a4ba591..d975dc052 100644
--- a/samples/hello_world/prj.conf
+++ b/samples/hello_world/prj.conf
@@ -1 +1,2 @@
 # nothing here
+CONFIG_EXTERNAL_KERNEL_SYSTEMS="/home/sebo/workspace_zephyr/led_strip"