add ability for custom code.py contents

Author: todbot

py/circuitpy_mpconfig.mk

@@ -67,6 +67,11 @@ CIRCUITPY_MESSAGE_COMPRESSION_LEVEL ?= 9
 CIRCUITPY_OPTIMIZE_PROPERTY_FLASH_SIZE ?= 0
 CFLAGS += -DCIRCUITPY_OPTIMIZE_PROPERTY_FLASH_SIZE=$(CIRCUITPY_OPTIMIZE_PROPERTY_FLASH_SIZE)
 
+# The contents of compiled-in code.py file.
+# Ports can override to import frozen modules to compile-in running code
+CIRCUITPY_CODEPY_CONTENTS ?= "print(\"Hello World!\")\n"
+CFLAGS += -DCIRCUITPY_CODEPY_CONTENTS='$(CIRCUITPY_CODEPY_CONTENTS)'
+
 # async/await language keyword support
 MICROPY_PY_ASYNC_AWAIT ?= $(CIRCUITPY_FULL_BUILD)
 CFLAGS += -DMICROPY_PY_ASYNC_AWAIT=$(MICROPY_PY_ASYNC_AWAIT)

supervisor/shared/filesystem.c

@@ -134,7 +134,7 @@ bool filesystem_init(bool create_allowed, bool force_create) {
         make_empty_file(&vfs_fat->fatfs, "/settings.toml");
         #endif
         // make a sample code.py file
-        MAKE_FILE_WITH_OPTIONAL_CONTENTS(&vfs_fat->fatfs, "/code.py", "print(\"Hello World!\")\n");
+        MAKE_FILE_WITH_OPTIONAL_CONTENTS(&vfs_fat->fatfs, "/code.py", CIRCUITPY_CODEPY_CONTENTS);
 
         // create empty lib directory
         res = f_mkdir(&vfs_fat->fatfs, "/lib");