rp2: Switch to use new cstack API for stack limit checks.

This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/rp2/main.c

@@ -27,11 +27,11 @@
 #include <stdio.h>
 
 #include "py/compile.h"
+#include "py/cstack.h"
 #include "py/runtime.h"
 #include "py/gc.h"
 #include "py/mperrno.h"
 #include "py/mphal.h"
-#include "py/stackctrl.h"
 #include "extmod/modbluetooth.h"
 #include "extmod/modnetwork.h"
 #include "shared/readline/readline.h"
@@ -114,8 +114,7 @@ int main(int argc, char **argv) {
     mp_hal_time_ns_set_from_rtc();
 
     // Initialise stack extents and GC heap.
-    mp_stack_set_top(&__StackTop);
-    mp_stack_set_limit(&__StackTop - &__StackBottom - 256);
+    mp_cstack_init_with_top(&__StackTop, &__StackTop - &__StackBottom);
     gc_init(&__GcHeapStart, &__GcHeapEnd);
 
     #if MICROPY_PY_LWIP

ports/rp2/mpconfigport.h

@@ -81,6 +81,7 @@
 #define MICROPY_TRACKED_ALLOC                   (MICROPY_SSL_MBEDTLS || MICROPY_BLUETOOTH_BTSTACK)
 #define MICROPY_READER_VFS                      (1)
 #define MICROPY_ENABLE_GC                       (1)
+#define MICROPY_STACK_CHECK_MARGIN              (256)
 #define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF  (1)
 #define MICROPY_LONGINT_IMPL                    (MICROPY_LONGINT_IMPL_MPZ)
 #define MICROPY_FLOAT_IMPL                      (MICROPY_FLOAT_IMPL_FLOAT)