Remove obsolete bss-related code/build features

GC for unix/windows builds doesn't make use of the bss section anymore,
so we do not need the (sometimes complicated) build features and code related to it

py/gc.c

@@ -695,11 +695,9 @@ void gc_dump_alloc_table(void) {
             case AT_FREE: c = '.'; break;
             /* this prints out if the object is reachable from BSS or STACK (for unix only)
             case AT_HEAD: {
-                extern char __bss_start, _end;
-                extern char *stack_top;
                 c = 'h';
-                void **ptrs = (void**)&__bss_start;
-                mp_uint_t len = ((mp_uint_t)&_end - (mp_uint_t)&__bss_start) / sizeof(mp_uint_t);
+                void **ptrs = (void**)(void*)&mp_state_ctx;
+                mp_uint_t len = offsetof(mp_state_ctx_t, vm.stack_top) / sizeof(mp_uint_t);
                 for (mp_uint_t i = 0; i < len; i++) {
                     mp_uint_t ptr = (mp_uint_t)ptrs[i];
                     if (VERIFY_PTR(ptr) && BLOCK_FROM_PTR(ptr) == bl) {
@@ -709,7 +707,7 @@ void gc_dump_alloc_table(void) {
                 }
                 if (c == 'h') {
                     ptrs = (void**)&c;
-                    len = ((mp_uint_t)stack_top - (mp_uint_t)&c) / sizeof(mp_uint_t);
+                    len = ((mp_uint_t)MP_STATE_VM(stack_top) - (mp_uint_t)&c) / sizeof(mp_uint_t);
                     for (mp_uint_t i = 0; i < len; i++) {
                         mp_uint_t ptr = (mp_uint_t)ptrs[i];
                         if (VERIFY_PTR(ptr) && BLOCK_FROM_PTR(ptr) == bl) {

unix/Makefile

@@ -35,8 +35,8 @@ endif
 # if necessary override the value of 'CC' set in py/mkenv.mk
 ifeq ($(UNAME_S),Darwin)
 CC = clang
-# Use clang syntax for map file and set osx specific flags
-LDFLAGS_ARCH = -Wl,-order_file,$(BUILD)/order.def -Wl,-map,$@.map
+# Use clang syntax for map file
+LDFLAGS_ARCH = -Wl,-map,$@.map
 else
 # Use gcc syntax for map file
 LDFLAGS_ARCH = -Wl,-Map=$@.map,--cref
@@ -92,17 +92,6 @@ SRC_C = \
 	alloc.c \
 	$(SRC_MOD)
 
-ifeq ($(UNAME_S),Darwin)
-# Must be the last file in list of sources
-SRC_C += seg_helpers.c
-
-# making seg_helpers.c rely on order.def will force order.def to be created
-seg_helpers.c: $(BUILD)/order.def
-
-# create order.def in build directory
-$(BUILD)/order.def:
-	$(Q)echo "seg_helpers.o: ___bss_start" > $@
-endif
 
 OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 

windows/Makefile

@@ -37,7 +37,6 @@ SRC_C = \
 	realpath.c \
 	init.c \
 	sleep.c \
-	bss.c \
 
 OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 

windows/init.c

@@ -28,12 +28,9 @@
 #include <stdio.h>
 #include <windows.h>
 
-extern void getbss();
-
 HANDLE hSleepEvent = NULL;
 
 void init() {
-    getbss();
     hSleepEvent = CreateEvent(NULL, TRUE, FALSE, FALSE);
 #ifdef __MINGW32__
     putenv("PRINTF_EXPONENT_DIGITS=2");

windows/mpconfigport.h

@@ -166,7 +166,8 @@ void msec_sleep(double msec);
 #define S_ISDIR(m)                  (((m) & S_IFMT) == S_IFDIR)
 
 
-// Put static/global variables in sections with a known name we can lookup for the GC
+// Put static/global variables in sections with a known name
+// This used to be required for GC, not the case anymore but keep it as it makes the map file easier to inspect
 // For this to work this header must be included by all sources, which is the case normally
 #define MICROPY_PORT_DATASECTION "upydata"
 #define MICROPY_PORT_BSSSECTION "upybss"
@@ -183,8 +184,3 @@ void msec_sleep(double msec);
 
 int snprintf(char *dest, size_t count, const char *format, ...);
 #endif
-
-// MingW specifics
-#ifdef __MINGW32__
-#define MICROPY_PORT_BSSSECTION ".bss"
-#endif