Added in documentation on how to consume from a main project. Added d…

…efault PORT selection for native POSIX and MINGW platforms.

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.15)
 
 # User is responsible to one mandatory option:
-#   FREERTOS_PORT
+#   FREERTOS_PORT, if not specified and native port detected, uses the native compile.
 #
 # User is responsible for one library target:
 #   freertos_config ,typcially an INTERFACE library
@@ -49,16 +49,14 @@ endif()
 set(FREERTOS_HEAP "4" CACHE STRING "FreeRTOS heap model number. 1 .. 5. Or absolute path to custom heap source file")
 
 # FreeRTOS port option
-set(FREERTOS_PORT "" CACHE STRING "FreeRTOS port name")
-
 if(NOT FREERTOS_PORT)
-    message(FATAL_ERROR " FREERTOS_PORT is not set. Please specify it from top-level CMake file (example):\n"
+    message(WARNING " FREERTOS_PORT is not set. Please specify it from top-level CMake file (example):\n"
         "  set(FREERTOS_PORT GCC_ARM_CM4F CACHE STRING \"\")\n"
         " or from CMake command line option:\n"
         "  -DFREERTOS_PORT=GCC_ARM_CM4F\n"
         " \n"
         " Available port options:\n"
-        " A_CUSTOM_PORT                    - Compiler: UserDefined   Target: User Defined\n"
+        " A_CUSTOM_PORT                    - Compiler: User Defined  Target: User Defined\n"
         " BCC_16BIT_DOS_FLSH186            - Compiler: BCC           Target: 16 bit DOS Flsh186\n"
         " BCC_16BIT_DOS_PC                 - Compiler: BCC           Target: 16 bit DOS PC\n"
         " CCS_ARM_CM3                      - Compiler: CCS           Target: ARM Cortex-M3\n"
@@ -203,6 +201,14 @@ if(NOT FREERTOS_PORT)
         " CDK_THEAD_CK802                  - Compiler: CDK           Target: T-head CK802\n"
         " XCC_XTENSA                       - Compiler: XCC           Target: Xtensa\n"
         " WIZC_PIC18                       - Compiler: WizC          Target: PIC18")
+    # Native FREERTOS_PORT for Linux and Windows MINGW builds
+    if(UNIX)
+        message(STATUS " Auto-Detected Unix, setting FREERTOS_PORT=GCC_POSIX")
+        set(FREERTOS_PORT GCC_POSIX CACHE STRING "FreeRTOS port name")
+    elseif(MINGW)
+        message(STATUS " Auto-Detected MINGW, setting FREERTOS_PORT=MSVC_MINGW")
+        set(FREERTOS_PORT MSVC_MINGW CACHE STRING "FreeRTOS port name")
+    endif()
 elseif((FREERTOS_PORT STREQUAL "A_CUSTOM_PORT") AND (NOT TARGET freertos_kernel_port) )
     message(FATAL_ERROR " FREERTOS_PORT is set to A_CUSTOM_PORT. Please specify the custom port target with all necessary files. For example:\n"
     " Assuming a directory of:\n"

README.md

@@ -8,7 +8,53 @@ Additionally, for FreeRTOS kernel feature information refer to the [Developer Do
 ### Getting help
 If you have any questions or need assistance troubleshooting your FreeRTOS project, we have an active community that can help on the [FreeRTOS Community Support Forum](https://forums.freertos.org).
 
-## Cloning this repository
+## To consume FreeRTOS-Kernel
+
+### Consume with CMake
+If using CMake, it is recommended to use this repository using FetchContent.
+Add the following into your project's main or a subdirectory's `CMakeLists.txt`:
+
+- Define the source and version/tag you want to use:
+
+```cmake
+FetchContent_Declare( freertos_kernel
+  GIT_REPOSITORY https://github.com/FreeRTOS/FreeRTOS-Kernel.git
+  GIT_TAG        master #Note: Best practice to use specific git-hash or tagged version
+)
+```
+
+- Add a freertos_config library (typically an INTERFACE library) The following assumes the directory structure:
+  - `include/FreeRTOSConfig.h`
+```cmake
+add_library(freertos_config INTERFACE)
+
+target_include_directories(freertos_config SYSTEM
+INTERFACE
+    include
+)
+
+target_compile_definitions(freertos_config
+  INTERFACE
+    projCOVERAGE_TEST=0
+)
+```
+
+- Configure the FreeRTOS-Kernel and make it available
+  - this particular example supports a native and cross-compiled build option.
+
+```cmake
+set( FREERTOS_HEAP "4" CACHE STRING "" FORCE)
+# Select the native compile PORT
+set( FREERTOS_PORT "GCC_POSIX" CACHE STRING "" FORCE)
+# Select the cross-compile PORT
+if (CMAKE_CROSSCOMPILING)
+  set(FREERTOS_PORT "GCC_ARM_CA9" CACHE STRING "" FORCE)
+endif()
+
+FetchContent_MakeAvailable(freertos_kernel)
+```
+
+### Consuming stand-alone - Cloning this repository
 
 To clone using HTTPS:
 ```
@@ -36,4 +82,3 @@ FreeRTOS files are formatted using the "uncrustify" tool. The configuration file
 ### Spelling
 *lexicon.txt* contains words that are not traditionally found in an English dictionary. It is used by the spellchecker to verify the various jargon, variable names, and other odd words used in the FreeRTOS code base. If your pull request fails to pass the spelling and you believe this is a mistake, then add the word to *lexicon.txt*. 
 Note that only the FreeRTOS Kernel source files are checked for proper spelling, the portable section is ignored.
-