Recommended way to build MicroPython as a library?

[bogdanm]

Hi, I am looking at using MicroPython in a project, but not in its standalone variant. This means that the project has its own source tree (including its own main function) and will initialize and start MicroPython as needed, so I'm looking for a way to build MicroPython as a library that I can link with my own code. I managed to do that, but I'm wondering if there's a simpler (or "more standard") way to do this that I'm missing. My application uses Zephyr, so I'm using the Zephyr port or MicroPython as follows:

1. I added these lines to my top level CMakeLists.txt:

# Set the MicroPython port configuration options before including it
set(CONFIG_MICROPY_CONFIGFILE "mpconfigport.h")
set(CONFIG_MICROPY_HEAP_SIZE 16384)
add_subdirectory(${CMAKE_SOURCE_DIR}/micropython/ports/zephyr)
add_dependencies(app micropython)

2. I modified ports/zephyr/CMakeLists.txt as follows:

--- a/ports/zephyr/CMakeLists.txt
+++ b/ports/zephyr/CMakeLists.txt
@@ -101,6 +100,8 @@ zephyr_library_include_directories(
     ${MICROPY_INC_CORE}
     ${MICROPY_PORT_DIR}
     ${CMAKE_CURRENT_BINARY_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_BINARY_DIR}
 )

 zephyr_library_compile_options(
@@ -123,9 +124,9 @@ add_dependencies(${MICROPY_TARGET} zephyr_generated_headers)

 include(${MICROPY_DIR}/py/mkrules.cmake)

-target_sources(app PRIVATE
-    src/zephyr_start.c
-    src/zephyr_getchar.c
-)
+#target_sources(app PRIVATE
+#    src/zephyr_start.c
+#    src/zephyr_getchar.c
+#)

In other words:

• I removed the parts related to generating an executable image (target_sources).
• I added CMAKE_BINARY_DIR to the include path, because some tools from the build system (like genhdr) output into CMAKE_BINARY_DIR instead of CMAKE_CURRENT_BINARY_DIR (which is relevant when add_subdirectory is used).

While this seems to do the trick, I'm wondering if there's a way to achieve this that doesn't require me to patch ports/zephyr/CMakeLists.txt.