stm32/modstm: Add MICROPY_PY_STM_CONST flag, clear it for STM32WL5.

MICROPY_PY_STM_CONST defaults to 1 if MICROPY_PY_STM is set.  Overriding to
0 disables the named register peripheral constants being including in the
stm32 module.

This saves about 7.5KB of code size for the STM32WL55, which is significant
as this SoC doesn't have a lot of flash.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/stm32/boards/NUCLEO_WL55/mpconfigboard.h

@@ -14,7 +14,8 @@
 #define MICROPY_PY_SOCKET                       (0)
 #define MICROPY_PY_NETWORK                      (0)
 #define MICROPY_PY_ONEWIRE                      (0)
-#define MICROPY_PY_STM                          (1)
+#define MICROPY_PY_STM                          (1) // for subghz radio functions
+#define MICROPY_PY_STM_CONST                    (0) // saves size, no named registers
 #define MICROPY_PY_PYB_LEGACY                   (0)
 #define MICROPY_PY_HEAPQ                        (0)
 

ports/stm32/make-stmconst.py

@@ -319,10 +319,10 @@ def main():
     print("")
 
     with open(args.qstr_filename, "wt") as qstr_file:
-        print("#if MICROPY_PY_STM", file=qstr_file)
+        print("#if MICROPY_PY_STM_CONST", file=qstr_file)
         for qstr in sorted(needed_qstrs):
             print("Q({})".format(qstr), file=qstr_file)
-        print("#endif // MICROPY_PY_STM", file=qstr_file)
+        print("#endif // MICROPY_PY_STM_CONST", file=qstr_file)
 
     with open(args.mpz_filename, "wt") as mpz_file:
         for mpz in sorted(needed_mpzs):

ports/stm32/modstm.c

@@ -45,7 +45,9 @@ STATIC const mp_rom_map_elem_t stm_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_mem16), MP_ROM_PTR(&machine_mem16_obj) },
     { MP_ROM_QSTR(MP_QSTR_mem32), MP_ROM_PTR(&machine_mem32_obj) },
 
+    #if MICROPY_PY_STM_CONST
     #include "genhdr/modstm_const.h"
+    #endif
 
     #if defined(STM32WB)
     { MP_ROM_QSTR(MP_QSTR_rfcore_status), MP_ROM_PTR(&rfcore_status_obj) },

ports/stm32/mpconfigboard_common.h

@@ -32,11 +32,16 @@
 /*****************************************************************************/
 // Feature settings with defaults
 
-// Whether to include the stm module, with peripheral register constants
+// Whether to include the stm module
 #ifndef MICROPY_PY_STM
 #define MICROPY_PY_STM (1)
 #endif
 
+// Whether to include named register constants in the stm module
+#ifndef MICROPY_PY_STM_CONST
+#define MICROPY_PY_STM_CONST (MICROPY_PY_STM)
+#endif
+
 // Whether to include the pyb module
 #ifndef MICROPY_PY_PYB
 #define MICROPY_PY_PYB (1)