Add stack validity check and raise an error when it happens.

The backtrace cannot be given because it relies on the validity
of the qstr data structures on the heap which may have been
corrupted.

In fact, it still can crash hard when the bytecode itself is
overwritten. To fix, we'd need a way to skip gathering the
backtrace completely.

This also increases the default stack size on M4s so it can
accomodate the stack needed by ASF4s nvm API.

1 files changed, 2 insertions, 2 deletions

diff --git a/main.c b/main.c
index 974f045fa..00babd20c 100755
--- a/main.c
+++ b/main.c
@@ -220,8 +220,8 @@ bool run_code_py(safe_mode_t safe_mode) {
     rgb_status_animation_t animation;
     prep_rgb_status_animation(&result, found_main, safe_mode, &animation);
     while (true) {
-        #ifdef MICROPY_VM_HOOK_LOOP
-            MICROPY_VM_HOOK_LOOP
+        #ifdef CIRCUITPY_SUPERVISOR_BACKGROUND
+            CIRCUITPY_SUPERVISOR_BACKGROUND
         #endif
         if (reload_requested) {
             return true;