ports/embed: Enable freezing Python modules.

Use FROZEN_MANIFEST as documented in docs/reference/manifest.rst.

Signed-off-by: Christian Walther <cwalther@gmx.ch>

examples/embedding-full/README.md

@@ -15,6 +15,8 @@ Building the example
 
 First build the embed port using:
 
+    $ make -C mpy-cross
+    $ cd examples/embedding-full
     $ make -f micropython_embed.mk submodules
     $ make -f micropython_embed.mk
 

examples/embedding-full/main.c

@@ -34,6 +34,9 @@ static const char *example_2 =
     "help(random)\n"
     "import time\n"
     "help(time)\n"
+    "import frozenhello\n"
+    "help(frozenhello)\n"
+    "print('frozenhello.hello():', frozenhello.hello())\n"
     "\n"
     "print('finish')\n"
     ;

examples/embedding-full/manifest.py

@@ -0,0 +1 @@
+module("frozenhello.py", base_path="modules")

examples/embedding-full/micropython_embed.mk

@@ -8,5 +8,8 @@ MICROPYTHON_TOP = ../..
 # Include modules from extmod in the output.
 EMBED_EXTRA = extmod
 
+# Freeze Python modules.
+FROZEN_MANIFEST ?= manifest.py
+
 # Include the main makefile fragment to build the MicroPython component.
 include $(MICROPYTHON_TOP)/ports/embed/embed.mk

examples/embedding-full/modules/frozenhello.py

@@ -0,0 +1,2 @@
+def hello():
+    return "Hello from the cold!"

examples/embedding-full/mpconfigport.h

@@ -36,3 +36,13 @@
 
 // We have our own implementation of mp_hal_stdout_tx_strn_cooked().
 #undef MP_PLAT_PRINT_STRN
+
+// Enable freezing of Python modules. These would be set automatically for the
+// port build based on the presence of FROZEN_MANIFEST by py/mkrules.mk, but
+// must be set explicitly for the application build.
+#define MICROPY_MODULE_FROZEN_MPY               1
+#define MICROPY_MODULE_FROZEN_STR               1
+#define MICROPY_QSTR_EXTRA_POOL                 mp_qstr_frozen_const_pool
+// must match MPY_TOOL_FLAGS or defaults for mpy-tool.py arguments
+#define MICROPY_LONGINT_IMPL                    (MICROPY_LONGINT_IMPL_MPZ)
+#define MPZ_DIG_SIZE                            (16)

ports/embed/embed.mk

@@ -34,6 +34,11 @@ GENHDR_OUTPUT = $(addprefix $(BUILD)/genhdr/, \
 	root_pointers.h \
 	)
 
+# Define the module freezing output.
+ifneq ($(FROZEN_MANIFEST),)
+FROZEN_OUTPUT = $(BUILD)/frozen_content.c
+endif
+
 # Define the top-level target, the generated output files.
 .PHONY: all
 all: micropython-embed-package
@@ -49,9 +54,12 @@ PACKAGE_DIR_LIST = $(addprefix $(PACKAGE_DIR)/,py extmod shared/runtime genhdr p
 ifeq ($(filter extmod,$(EMBED_EXTRA)),extmod)
 PACKAGE_DIR_LIST += $(addprefix $(PACKAGE_DIR)/,lib/uzlib lib/crypto-algorithms lib/re1.5)
 endif
+ifneq ($(FROZEN_MANIFEST),)
+PACKAGE_DIR_LIST += $(addprefix $(PACKAGE_DIR)/,frozen)
+endif
 
 .PHONY: micropython-embed-package
-micropython-embed-package: $(GENHDR_OUTPUT)
+micropython-embed-package: $(GENHDR_OUTPUT) $(FROZEN_OUTPUT)
 	$(ECHO) "Generate micropython_embed output:"
 	$(Q)$(RM) -rf $(PACKAGE_DIR_LIST)
 	$(Q)$(MKDIR) -p $(PACKAGE_DIR_LIST)
@@ -72,6 +80,10 @@ endif
 	$(Q)$(CP) $(TOP)/shared/runtime/gchelper_generic.c $(PACKAGE_DIR)/shared/runtime
 	$(ECHO) "- genhdr"
 	$(Q)$(CP) $(GENHDR_OUTPUT) $(PACKAGE_DIR)/genhdr
+ifneq ($(FROZEN_MANIFEST),)
+	$(ECHO) "- frozen"
+	$(Q)$(CP) $(FROZEN_OUTPUT) $(PACKAGE_DIR)/frozen
+endif
 	$(ECHO) "- port"
 	$(Q)$(CP) $(MICROPYTHON_EMBED_PORT)/port/*.[ch] $(PACKAGE_DIR)/port