From 0eb08509f0f9e6aa353782b9d20c69714dd77034 Mon Sep 17 00:00:00 2001
From: Scott Shawcroft <scott@tannewt.org>
Date: Tue, 21 Mar 2023 16:42:49 -0700
Subject: [PATCH 1/2] Make set_stack_limit respect fixed stack

Fixes #2830
---
 shared-bindings/supervisor/Runtime.c |  6 +++++-
 supervisor/shared/stack.c            | 12 ++++++++++--
 supervisor/shared/stack.h            |  2 +-
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/shared-bindings/supervisor/Runtime.c b/shared-bindings/supervisor/Runtime.c
index db3d8d1e4d..ecdd914a8f 100644
--- a/shared-bindings/supervisor/Runtime.c
+++ b/shared-bindings/supervisor/Runtime.c
@@ -197,7 +197,11 @@ MP_DEFINE_CONST_FUN_OBJ_1(supervisor_runtime_get_next_stack_limit_obj, superviso
 STATIC mp_obj_t supervisor_runtime_set_next_stack_limit(mp_obj_t self, mp_obj_t size_obj) {
     mp_int_t size = mp_obj_get_int(size_obj);
     mp_arg_validate_int_min(size, 256, MP_QSTR_size);
-    set_next_stack_size(size);
+    if (!set_next_stack_size(size)) {
+        mp_raise_msg_varg(&mp_type_AttributeError,
+            MP_ERROR_TEXT("can't set attribute '%q'"),
+            MP_QSTR_next_stack_limit);
+    }
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_2(supervisor_runtime_set_next_stack_limit_obj, supervisor_runtime_set_next_stack_limit);
diff --git a/supervisor/shared/stack.c b/supervisor/shared/stack.c
index be97cee234..148bb0bbd5 100644
--- a/supervisor/shared/stack.c
+++ b/supervisor/shared/stack.c
@@ -35,7 +35,7 @@
 extern uint32_t _estack;
 
 // Requested size.
-static uint32_t next_stack_size = CIRCUITPY_DEFAULT_STACK_SIZE;
+static uint32_t next_stack_size = 0;
 static uint32_t current_stack_size = 0;
 // Actual location and size, may be larger than requested.
 static uint32_t *stack_limit = NULL;
@@ -49,11 +49,15 @@ static void allocate_stack(void) {
         stack_limit = port_stack_get_limit();
         stack_length = (port_stack_get_top() - stack_limit) * sizeof(uint32_t);
         current_stack_size = stack_length;
+        next_stack_size = stack_length;
     } else {
         mp_uint_t regs[10];
         mp_uint_t sp = cpu_get_regs_and_sp(regs);
 
         mp_uint_t c_size = (mp_uint_t)port_stack_get_top() - sp;
+        if (next_stack_size == 0) {
+            next_stack_size = CIRCUITPY_DEFAULT_STACK_SIZE;
+        }
         supervisor_allocation *stack_alloc = allocate_memory(c_size + next_stack_size + EXCEPTION_STACK_SIZE, true, false);
         if (stack_alloc == NULL) {
             stack_alloc = allocate_memory(c_size + CIRCUITPY_DEFAULT_STACK_SIZE + EXCEPTION_STACK_SIZE, true, false);
@@ -103,8 +107,12 @@ size_t stack_get_length(void) {
     return stack_length;
 }
 
-void set_next_stack_size(uint32_t size) {
+bool set_next_stack_size(uint32_t size) {
+    if (port_has_fixed_stack()) {
+        return false;
+    }
     next_stack_size = size;
+    return true;
 }
 
 uint32_t get_next_stack_size(void) {
diff --git a/supervisor/shared/stack.h b/supervisor/shared/stack.h
index 4acda57354..4a03fcf275 100644
--- a/supervisor/shared/stack.h
+++ b/supervisor/shared/stack.h
@@ -37,7 +37,7 @@ void stack_resize(void);
 uint32_t *stack_get_bottom(void);
 size_t stack_get_length(void);
 // Next/current requested stack size.
-void set_next_stack_size(uint32_t size);
+bool set_next_stack_size(uint32_t size);
 uint32_t get_next_stack_size(void);
 uint32_t get_current_stack_size(void);
 bool stack_ok(void);

From b5834886521a16419af25c512472029f97234cd6 Mon Sep 17 00:00:00 2001
From: Scott Shawcroft <scott@tannewt.org>
Date: Wed, 22 Mar 2023 09:24:03 -0700
Subject: [PATCH 2/2] Fix stub

---
 supervisor/stub/stack.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/supervisor/stub/stack.c b/supervisor/stub/stack.c
index 2abc197878..bb6e0d4cb0 100644
--- a/supervisor/stub/stack.c
+++ b/supervisor/stub/stack.c
@@ -39,8 +39,9 @@ void stack_init(void) {
 void stack_resize(void) {
 }
 
-void set_next_stack_size(uint32_t size) {
+bool set_next_stack_size(uint32_t size) {
     (void)size;
+    return true;
 }
 
 uint32_t get_current_stack_size(void) {