samples: use ZEPHYR_EXTRA_MODULES instead of ZEPHYR_MODULES

ZEPHYR_EXTRA_MODULES should be used when the intention is to add an
extra module to those already found by west. The QEMU targets didn't
require additional modules, so this was not apparent.

Fixes #17

README.rst

@@ -4,9 +4,9 @@ Rust on Zephyr RTOS
 Overview
 ********
 Zephyr_ module for building a Cargo project and linking it into a Zephyr image.
-Add this directory to ZEPHYR_MODULES to build a Cargo library project (located
-in the Zephyr app's source directory by default) and link it into the Zephyr
-app.
+Add this directory to ZEPHYR_EXTRA_MODULES to build a Cargo library project
+(located in the Zephyr app's source directory by default) and link it into the
+Zephyr app.
 
 Features
 ========

samples/futures/CMakeLists.txt

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.13.1)
+
+# For this example, add ZEPHYR_RUST as a zephyr module. Not needed if added in
+# your environment or managed by west.
 get_filename_component(ZEPHYR_RUST ${CMAKE_CURRENT_SOURCE_DIR}/../.. ABSOLUTE)
-list(APPEND ZEPHYR_MODULES ${ZEPHYR_RUST})
+list(APPEND ZEPHYR_EXTRA_MODULES ${ZEPHYR_RUST})
+
 include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
 project(rust)
 target_sources(app PRIVATE ./src/main.c)

samples/rust-app/CMakeLists.txt

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.13.1)
+
+# For this example, add ZEPHYR_RUST as a zephyr module. Not needed if added in
+# your environment or managed by west.
 get_filename_component(ZEPHYR_RUST ${CMAKE_CURRENT_SOURCE_DIR}/../.. ABSOLUTE)
-list(APPEND ZEPHYR_MODULES ${ZEPHYR_RUST})
+list(APPEND ZEPHYR_EXTRA_MODULES ${ZEPHYR_RUST})
+
 include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
 project(hello_world)
 target_sources(app PRIVATE ./src/main.c)

samples/serial/CMakeLists.txt

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.13.1)
+
+# For this example, add ZEPHYR_RUST as a zephyr module. Not needed if added in
+# your environment or managed by west.
 get_filename_component(ZEPHYR_RUST ${CMAKE_CURRENT_SOURCE_DIR}/../.. ABSOLUTE)
-list(APPEND ZEPHYR_MODULES ${ZEPHYR_RUST})
+list(APPEND ZEPHYR_EXTRA_MODULES ${ZEPHYR_RUST})
+
 list(APPEND QEMU_EXTRA_FLAGS -serial tcp:localhost:4444,server,nowait)
 include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
 project(hello_world)

tests/rust/CMakeLists.txt

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.13.1)
+
+# For this example, add ZEPHYR_RUST as a zephyr module. Not needed if added in
+# your environment or managed by west.
 get_filename_component(ZEPHYR_RUST ${CMAKE_CURRENT_SOURCE_DIR}/../.. ABSOLUTE)
-list(APPEND ZEPHYR_MODULES ${ZEPHYR_RUST})
+list(APPEND ZEPHYR_EXTRA_MODULES ${ZEPHYR_RUST})
+
 include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
 project(rust)
 target_sources(app PRIVATE ./src/main.c)

tests/semaphore/CMakeLists.txt

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 cmake_minimum_required(VERSION 3.13.1)
+
+# For this example, add ZEPHYR_RUST as a zephyr module. Not needed if added in
+# your environment or managed by west.
 get_filename_component(ZEPHYR_RUST ${CMAKE_CURRENT_SOURCE_DIR}/../.. ABSOLUTE)
-list(APPEND ZEPHYR_MODULES ${ZEPHYR_RUST})
+list(APPEND ZEPHYR_EXTRA_MODULES ${ZEPHYR_RUST})
+
 include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
 project(rust)
 target_sources(app PRIVATE ./src/main.c)