Use less free stack, more heap. This lets us claim a whole kilobyte back from

davidgiven · davidgiven · commit d39b4dba5124 · 2024-06-04T23:49:23.000+02:00
the C stack.
diff --git a/ports/tc32/gccollect.c b/ports/tc32/gccollect.c
@@ -27,9 +27,12 @@
 #include "py/gc.h"
 #include "py/mpthread.h"
 #include "shared/runtime/gchelper.h"
-// #include "shared/runtime/softtimer.h"
 
 void gc_collect(void) {
+  /* Check the flag byte to make sure the stack isn't corrupted. */
+  if (*(uint8_t*)0x80bc00 != 42)
+    mp_printf(&mp_plat_print, "mpy: stack corrupted! About to crash!\n");
+
   // start the GC
   gc_collect_start();
 
@@ -41,9 +44,6 @@ void gc_collect(void) {
   mp_thread_gc_others();
 #endif
 
-  // trace soft timer nodes
-  // soft_timer_gc_mark_all();
-
   // end the GC
   gc_collect_end();
 }
diff --git a/ports/tc32/main.c b/ports/tc32/main.c
@@ -72,9 +72,13 @@ MP_NOINLINE static void hard_init() {
 MP_NOINLINE static void soft_init() {
 
   /* The Telink SDK doesn't define any symbols for these, so we just hard code
-   * it. The stack starts at the end of memory, 0x80c000. We leave 2kB for it,
-   * meaning that our heap needs to end at 0x80b800. */
-  gc_init((void *)&_end_bss_, (void *)0x80b800);
+   * it. The stack starts at the end of memory, 0x80c000. We leave 1kB for it,
+   * meaning that our heap needs to end at 0x80bc00. */
+  gc_init((void *)&_end_bss_, (void *)0x80bc00);
+
+  /* Set up the stack corruption flag byte. */
+  *(uint8_t*)0x80bc00 = 42;
+
   mp_init();
   machine_init();
 }
diff --git a/ports/tc32/mpconfigport.h b/ports/tc32/mpconfigport.h
@@ -18,9 +18,10 @@
 #define MICROPY_DEBUG_PRINTERS (0)
 #define MICROPY_ENABLE_FINALISER (1)
 #define MICROPY_LONGINT_IMPL (MICROPY_LONGINT_IMPL_MPZ)
+#define MICROPY_STACKLESS (1)
 
 // This doesn't work. Maybe Telink's floating point emulation is broken.
-// #define MICROPY_FLOAT_IMPL (MICROPY_FLOAT_IMPL_FLOAT)
+#define MICROPY_FLOAT_IMPL (MICROPY_FLOAT_IMPL_FLOAT)
 
 #define MICROPY_PY_MACHINE (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/tc32/modmachine.c"
