extmod/modmachine: Add MICROPY_PY_MACHINE_MEMX configuration option.

Enabled by default.

Signed-off-by: Damien George <damien@micropython.org>

extmod/machine_mem.c

@@ -27,7 +27,7 @@
 #include "py/runtime.h"
 #include "extmod/modmachine.h"
 
-#if MICROPY_PY_MACHINE
+#if MICROPY_PY_MACHINE_MEMX
 
 // If you wish to override the functions for mapping the machine_mem read/write
 // address, then add a #define for MICROPY_MACHINE_MEM_GET_READ_ADDR and/or
@@ -113,4 +113,4 @@ const machine_mem_obj_t machine_mem8_obj = {{&machine_mem_type}, 1};
 const machine_mem_obj_t machine_mem16_obj = {{&machine_mem_type}, 2};
 const machine_mem_obj_t machine_mem32_obj = {{&machine_mem_type}, 4};
 
-#endif // MICROPY_PY_MACHINE
+#endif // MICROPY_PY_MACHINE_MEMX

extmod/modmachine.c

@@ -138,9 +138,11 @@ static const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_machine) },
 
     // Memory access objects.
+    #if MICROPY_PY_MACHINE_MEMX
     { MP_ROM_QSTR(MP_QSTR_mem8), MP_ROM_PTR(&machine_mem8_obj) },
     { MP_ROM_QSTR(MP_QSTR_mem16), MP_ROM_PTR(&machine_mem16_obj) },
     { MP_ROM_QSTR(MP_QSTR_mem32), MP_ROM_PTR(&machine_mem32_obj) },
+    #endif
 
     // Miscellaneous functions.
     #if MICROPY_PY_MACHINE_BARE_METAL_FUNCS

py/mpconfig.h

@@ -1702,6 +1702,11 @@ typedef double mp_float_t;
 #define MICROPY_PY_MACHINE_PULSE (0)
 #endif
 
+// Whether to provide the "machine.mem8/16/32" objects
+#ifndef MICROPY_PY_MACHINE_MEMX
+#define MICROPY_PY_MACHINE_MEMX (MICROPY_PY_MACHINE)
+#endif
+
 // Whether to provide the "machine.Signal" class
 #ifndef MICROPY_PY_MACHINE_SIGNAL
 #define MICROPY_PY_MACHINE_SIGNAL (MICROPY_PY_MACHINE)