Merge pull request #8553 from tannewt/switch_to_split_heap

Switch all ports to auto-growing split heap

.gitmodules

@@ -351,3 +351,6 @@
 [submodule "lib/certificates"]
 	path = lib/certificates
 	url = https://github.com/adafruit/certificates
+[submodule "lib/tlsf"]
+	path = lib/tlsf
+	url = https://github.com/espressif/tlsf.git

lib/libm/fabsf.c

@@ -0,0 +1,14 @@
+/*****************************************************************************/
+/*****************************************************************************/
+// fabsf from musl-0.9.15
+/*****************************************************************************/
+/*****************************************************************************/
+
+#include "libm.h"
+
+float fabsf(float x)
+{
+	union {float f; uint32_t i;} u = {x};
+	u.i &= 0x7fffffff;
+	return u.f;
+}

lib/tlsf

@@ -0,0 +1 @@
+Subproject commit 8c9cd0517adf99e363812e9a295dfe3898fdd345

locale/circuitpython.pot

@@ -1271,10 +1271,6 @@ msgstr ""
 msgid "Invalid BSSID"
 msgstr ""
 
-#: main.c
-msgid "Invalid CIRCUITPY_PYSTACK_SIZE\n"
-msgstr ""
-
 #: shared-bindings/wifi/Radio.c
 msgid "Invalid MAC address"
 msgstr ""
@@ -2164,7 +2160,7 @@ msgid "Unable to allocate buffers for signed conversion"
 msgstr ""
 
 #: supervisor/shared/safe_mode.c
-msgid "Unable to allocate the heap."
+msgid "Unable to allocate to the heap."
 msgstr ""
 
 #: ports/espressif/common-hal/busio/I2C.c
@@ -2735,7 +2731,7 @@ msgstr ""
 msgid "can't set attribute"
 msgstr ""
 
-#: py/runtime.c shared-bindings/supervisor/Runtime.c
+#: py/runtime.c
 msgid "can't set attribute '%q'"
 msgstr ""
 
@@ -3004,12 +3000,6 @@ msgstr ""
 msgid "error = 0x%08lX"
 msgstr ""
 
-#: ports/espressif/common-hal/espcamera/Camera.c
-msgid ""
-"espcamera.Camera requires reserved PSRAM to be configured. See the "
-"documentation for instructions."
-msgstr ""
-
 #: py/runtime.c
 msgid "exceptions must derive from BaseException"
 msgstr ""

main.c

@@ -49,7 +49,6 @@
 #include "supervisor/board.h"
 #include "supervisor/cpu.h"
 #include "supervisor/filesystem.h"
-#include "supervisor/memory.h"
 #include "supervisor/port.h"
 #include "supervisor/serial.h"
 #include "supervisor/shared/reload.h"
@@ -65,6 +64,7 @@
 
 #include "shared-bindings/microcontroller/__init__.h"
 #include "shared-bindings/microcontroller/Processor.h"
+#include "shared-bindings/supervisor/__init__.h"
 #include "shared-bindings/supervisor/Runtime.h"
 
 #include "shared-bindings/os/__init__.h"
@@ -137,24 +137,36 @@ static void reset_devices(void) {
     #endif
 }
 
-#if MICROPY_ENABLE_PYSTACK
+STATIC uint8_t *_heap;
-STATIC supervisor_allocation *allocate_pystack(safe_mode_t safe_mode) {
+STATIC uint8_t *_pystack;
-    #if CIRCUITPY_OS_GETENV && CIRCUITPY_SETTABLE_PYSTACK
+
+#if MICROPY_ENABLE_PYSTACK || MICROPY_ENABLE_GC
+STATIC uint8_t *_allocate_memory(safe_mode_t safe_mode, const char *env_key, size_t default_size, size_t *final_size) {
+    *final_size = default_size;
+    #if CIRCUITPY_OS_GETENV
     if (safe_mode == SAFE_MODE_NONE) {
-        mp_int_t pystack_size = CIRCUITPY_PYSTACK_SIZE;
+        (void)common_hal_os_getenv_int(env_key, (mp_int_t *)final_size);
-        (void)common_hal_os_getenv_int("CIRCUITPY_PYSTACK_SIZE", &pystack_size);
+        if (*final_size < 0) {
-        supervisor_allocation *pystack = allocate_memory(pystack_size >= 384 ? pystack_size : 0, false, false);
+            *final_size = default_size;
-        if (pystack) {
-            return pystack;
         }
-        serial_write_compressed(MP_ERROR_TEXT("Invalid CIRCUITPY_PYSTACK_SIZE\n"));
     }
     #endif
-    return allocate_memory(CIRCUITPY_PYSTACK_SIZE, false, false);
+    uint8_t *ptr = port_malloc(*final_size, false);
+
+    #if CIRCUITPY_OS_GETENV
+    if (ptr == NULL) {
+        // Fallback to the build size.
+        ptr = port_malloc(default_size, false);
+    }
+    #endif
+    if (ptr == NULL) {
+        reset_into_safe_mode(SAFE_MODE_NO_HEAP);
+    }
+    return ptr;
 }
 #endif
 
-STATIC void start_mp(supervisor_allocation *heap, supervisor_allocation *pystack) {
+STATIC void start_mp(safe_mode_t safe_mode) {
     supervisor_workflow_reset();
 
     // Stack limit should be less than real stack size, so we have a chance
@@ -162,13 +174,12 @@ STATIC void start_mp(supervisor_allocation *heap, supervisor_allocation *pystack
     // stack is set to our current state. Not the actual top.
     mp_stack_ctrl_init();
 
-    uint32_t *stack_bottom = stack_get_bottom();
+    uint32_t *stack_bottom = port_stack_get_limit();
-    if (stack_bottom != NULL) {
+    uint32_t *stack_top = port_stack_get_top();
-        size_t stack_length = stack_get_length();
-        mp_stack_set_top(stack_bottom + (stack_length / sizeof(uint32_t)));
-        mp_stack_set_limit(stack_length - 1024);
-    }
 
+    size_t stack_length = (stack_top - stack_bottom) * sizeof(uint32_t);
+    mp_stack_set_top(stack_top);
+    mp_stack_set_limit(stack_length - CIRCUITPY_EXCEPTION_STACK_SIZE);
 
     #if MICROPY_MAX_STACK_USAGE
     // _ezero (same as _ebss) is an int, so start 4 bytes above it.
@@ -186,11 +197,15 @@ STATIC void start_mp(supervisor_allocation *heap, supervisor_allocation *pystack
     readline_init0();
 
     #if MICROPY_ENABLE_PYSTACK
-    mp_pystack_init(pystack->ptr, pystack->ptr + get_allocation_length(pystack) / sizeof(size_t));
+    size_t pystack_size = 0;
+    _pystack = _allocate_memory(safe_mode, "CIRCUITPY_PYSTACK_SIZE", CIRCUITPY_PYSTACK_SIZE, &pystack_size);
+    mp_pystack_init(_pystack, _pystack + pystack_size / sizeof(size_t));
     #endif
 
     #if MICROPY_ENABLE_GC
-    gc_init(heap->ptr, heap->ptr + get_allocation_length(heap) / 4);
+    size_t heap_size = 0;
+    _heap = _allocate_memory(safe_mode, "CIRCUITPY_HEAP_START_SIZE", CIRCUITPY_HEAP_START_SIZE, &heap_size);
+    gc_init(_heap, _heap + heap_size / 4);
     #endif
     mp_init();
     mp_obj_list_init((mp_obj_list_t *)mp_sys_path, 0);
@@ -227,6 +242,13 @@ STATIC void stop_mp(void) {
     qstr_reset();
 
     gc_deinit();
+    port_free(_heap);
+    _heap = NULL;
+
+    #if MICROPY_ENABLE_PYSTACK
+    port_free(_pystack);
+    _pystack = NULL;
+    #endif
 }
 
 STATIC const char *_current_executing_filename = NULL;
@@ -300,33 +322,34 @@ STATIC void count_strn(void *data, const char *str, size_t len) {
     *(size_t *)data += len;
 }
 
-STATIC void cleanup_after_vm(supervisor_allocation *heap, supervisor_allocation *pystack, mp_obj_t exception) {
+STATIC void cleanup_after_vm(mp_obj_t exception) {
     // Get the traceback of any exception from this run off the heap.
     // MP_OBJ_SENTINEL means "this run does not contribute to traceback storage, don't touch it"
     // MP_OBJ_NULL (=0) means "this run completed successfully, clear any stored traceback"
     if (exception != MP_OBJ_SENTINEL) {
-        free_memory(prev_traceback_allocation);
+        if (prev_traceback_string != NULL) {
+            port_free(prev_traceback_string);
+            prev_traceback_string = NULL;
+        }
         // ReloadException is exempt from traceback printing in pyexec_file(), so treat it as "no
         // traceback" here too.
         if (exception && exception != MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_reload_exception))) {
             size_t traceback_len = 0;
             mp_print_t print_count = {&traceback_len, count_strn};
             mp_obj_print_exception(&print_count, exception);
-            prev_traceback_allocation = allocate_memory(align32_size(traceback_len + 1), false, true);
+            prev_traceback_string = (char *)port_malloc(traceback_len + 1, false);
             // Empirically, this never fails in practice - even when the heap is totally filled up
             // with single-block-sized objects referenced by a root pointer, exiting the VM frees
             // up several hundred bytes, sufficient for the traceback (which tends to be shortened
             // because there wasn't memory for the full one). There may be convoluted ways of
             // making it fail, but at this point I believe they are not worth spending code on.
-            if (prev_traceback_allocation != NULL) {
+            if (prev_traceback_string != NULL) {
                 vstr_t vstr;
-                vstr_init_fixed_buf(&vstr, traceback_len, (char *)prev_traceback_allocation->ptr);
+                vstr_init_fixed_buf(&vstr, traceback_len, prev_traceback_string);
                 mp_print_t print = {&vstr, (mp_print_strn_t)vstr_add_strn};
                 mp_obj_print_exception(&print, exception);
-                ((char *)prev_traceback_allocation->ptr)[traceback_len] = '\0';
+                prev_traceback_string[traceback_len] = '\0';
             }
-        } else {
-            prev_traceback_allocation = NULL;
         }
     }
 
@@ -380,11 +403,6 @@ STATIC void cleanup_after_vm(supervisor_allocation *heap, supervisor_allocation
     // Free the heap last because other modules may reference heap memory and need to shut down.
     filesystem_flush();
     stop_mp();
-    free_memory(heap);
-    #if MICROPY_ENABLE_PYSTACK
-    free_memory(pystack);
-    #endif
-    supervisor_move_memory();
 
     // Let the workflows know we've reset in case they want to restart.
     supervisor_workflow_reset();
@@ -424,7 +442,6 @@ STATIC bool run_code_py(safe_mode_t safe_mode, bool *simulate_reset) {
     // Do the filesystem flush check before reload in case another write comes
     // in while we're doing the flush.
     if (safe_mode == SAFE_MODE_NONE) {
-        stack_resize();
         filesystem_flush();
     }
     if (safe_mode == SAFE_MODE_NONE && !autoreload_pending()) {
@@ -438,12 +455,7 @@ STATIC bool run_code_py(safe_mode_t safe_mode, bool *simulate_reset) {
         };
         #endif
 
-        supervisor_allocation *pystack = NULL;
+        start_mp(safe_mode);
-        #if MICROPY_ENABLE_PYSTACK
-        pystack = allocate_pystack(safe_mode);
-        #endif
-        supervisor_allocation *heap = allocate_remaining_memory();
-        start_mp(heap, pystack);
 
         #if CIRCUITPY_USB
         usb_setup_with_vm();
@@ -453,16 +465,15 @@ STATIC bool run_code_py(safe_mode_t safe_mode, bool *simulate_reset) {
         common_hal_os_chdir("/");
 
         // Check if a different run file has been allocated
-        if (next_code_allocation) {
+        if (next_code_configuration != NULL) {
-            next_code_info_t *info = ((next_code_info_t *)next_code_allocation->ptr);
+            next_code_configuration->options &= ~SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
-            info->options &= ~SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
+            next_code_options = next_code_configuration->options;
-            next_code_options = info->options;
+            if (next_code_configuration->filename[0] != '\0') {
-            if (info->filename[0] != '\0') {
                 // This is where the user's python code is actually executed:
-                const char *const filenames[] = { info->filename };
+                const char *const filenames[] = { next_code_configuration->filename };
                 found_main = maybe_run_list(filenames, MP_ARRAY_SIZE(filenames));
                 if (!found_main) {
-                    serial_write(info->filename);
+                    serial_write(next_code_configuration->filename);
                     serial_write_compressed(MP_ERROR_TEXT(" not found.\n"));
                 }
             }
@@ -494,16 +505,16 @@ STATIC bool run_code_py(safe_mode_t safe_mode, bool *simulate_reset) {
 
 
         // Finished executing python code. Cleanup includes filesystem flush and a board reset.
-        cleanup_after_vm(heap, pystack, _exec_result.exception);
+        cleanup_after_vm(_exec_result.exception);
         _exec_result.exception = NULL;
 
         // If a new next code file was set, that is a reason to keep it (obviously). Stuff this into
         // the options because it can be treated like any other reason-for-stickiness bit. The
         // source is different though: it comes from the options that will apply to the next run,
         // while the rest of next_code_options is what applied to this run.
-        if (next_code_allocation != NULL &&
+        if (next_code_configuration != NULL &&
-            (((next_code_info_t *)next_code_allocation->ptr)->options & SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET)) {
+            next_code_configuration->options & SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET) {
-            next_code_options |= SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
+            next_code_configuration->options |= SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
         }
 
         if (_exec_result.return_code & PYEXEC_RELOAD) {
@@ -757,9 +768,9 @@ STATIC bool run_code_py(safe_mode_t safe_mode, bool *simulate_reset) {
     #endif
 
     // free code allocation if unused
-    if ((next_code_options & next_code_stickiness_situation) == 0) {
+    if (next_code_configuration != NULL && (next_code_configuration->options & next_code_stickiness_situation) == 0) {
-        free_memory(next_code_allocation);
+        port_free(next_code_configuration);
-        next_code_allocation = NULL;
+        next_code_configuration = NULL;
     }
 
     #if CIRCUITPY_STATUS_LED
@@ -791,12 +802,7 @@ STATIC void __attribute__ ((noinline)) run_safemode_py(safe_mode_t safe_mode) {
         return;
     }
 
-    supervisor_allocation *pystack = NULL;
+    start_mp(safe_mode);
-    #if MICROPY_ENABLE_PYSTACK
-    pystack = allocate_pystack(safe_mode);
-    #endif
-    supervisor_allocation *heap = allocate_remaining_memory();
-    start_mp(heap, pystack);
 
     static const char *const safemode_py_filenames[] = {"safemode.py", "safemode.txt"};
     maybe_run_list(safemode_py_filenames, MP_ARRAY_SIZE(safemode_py_filenames));
@@ -807,7 +813,7 @@ STATIC void __attribute__ ((noinline)) run_safemode_py(safe_mode_t safe_mode) {
         set_safe_mode(SAFE_MODE_SAFEMODE_PY_ERROR);
     }
 
-    cleanup_after_vm(heap, pystack, _exec_result.exception);
+    cleanup_after_vm(_exec_result.exception);
     _exec_result.exception = NULL;
 }
 #endif
@@ -828,12 +834,7 @@ STATIC void __attribute__ ((noinline)) run_boot_py(safe_mode_t safe_mode) {
 
     // Do USB setup even if boot.py is not run.
 
-    supervisor_allocation *pystack = NULL;
+    start_mp(safe_mode);
-    #if MICROPY_ENABLE_PYSTACK
-    pystack = allocate_pystack(safe_mode);
-    #endif
-    supervisor_allocation *heap = allocate_remaining_memory();
-    start_mp(heap, pystack);
 
     #if CIRCUITPY_USB
     // Set up default USB values after boot.py VM starts but before running boot.py.
@@ -906,40 +907,19 @@ STATIC void __attribute__ ((noinline)) run_boot_py(safe_mode_t safe_mode) {
         #endif
     }
 
-    #if CIRCUITPY_USB
-    // Some data needs to be carried over from the USB settings in boot.py
-    // to the next VM, while the heap is still available.
-    // Its size can vary, so save it temporarily on the stack,
-    // and then when the heap goes away, copy it in into a
-    // storage_allocation.
-    size_t size = usb_boot_py_data_size();
-    uint8_t usb_boot_py_data[size];
-    usb_get_boot_py_data(usb_boot_py_data, size);
-    #endif
-
     port_post_boot_py(true);
 
-    cleanup_after_vm(heap, pystack, _exec_result.exception);
+    cleanup_after_vm(_exec_result.exception);
     _exec_result.exception = NULL;
 
     port_post_boot_py(false);
-
-    #if CIRCUITPY_USB
-    // Now give back the data we saved from the heap going away.
-    usb_return_boot_py_data(usb_boot_py_data, size);
-    #endif
 }
 
 STATIC int run_repl(safe_mode_t safe_mode) {
     int exit_code = PYEXEC_FORCED_EXIT;
-    stack_resize();
     filesystem_flush();
-    supervisor_allocation *pystack = NULL;
+
-    #if MICROPY_ENABLE_PYSTACK
+    start_mp(safe_mode);
-    pystack = allocate_pystack(safe_mode);
-    #endif
-    supervisor_allocation *heap = allocate_remaining_memory();
-    start_mp(heap, pystack);
 
     #if CIRCUITPY_USB
     usb_setup_with_vm();
@@ -987,7 +967,7 @@ STATIC int run_repl(safe_mode_t safe_mode) {
         exit_code = PYEXEC_DEEP_SLEEP;
     }
     #endif
-    cleanup_after_vm(heap, pystack, MP_OBJ_SENTINEL);
+    cleanup_after_vm(MP_OBJ_SENTINEL);
 
     // Also reset bleio. The above call omits it in case workflows should continue. In this case,
     // we're switching straight to another VM so we want to reset.
@@ -1010,6 +990,8 @@ int __attribute__((used)) main(void) {
     // initialise the cpu and peripherals
     set_safe_mode(port_init());
 
+    port_heap_init();
+
     // Turn on RX and TX LEDs if we have them.
     init_rxtx_leds();
 
@@ -1055,10 +1037,6 @@ int __attribute__((used)) main(void) {
         set_safe_mode(SAFE_MODE_NO_CIRCUITPY);
     }
 
-    // We maybe can't initialize the heap until here, because on espressif port we need to be able to check for reserved psram in settings.toml
-    // (but it's OK if this is a no-op due to the heap being initialized in port_init())
-    set_safe_mode(port_heap_init(get_safe_mode()));
-
     #if CIRCUITPY_ALARM
     // Record which alarm woke us up, if any.
     // common_hal_alarm_record_wake_alarm() should return a static, non-heap object
@@ -1188,11 +1166,8 @@ void gc_collect(void) {
 MP_WEAK void port_gc_collect() {
 }
 
-// A port may initialize the heap in port_init but if it cannot (for instance
+size_t gc_get_max_new_split(void) {
-// in espressif it must be done after CIRCUITPY is mounted) then it must provde
+    return port_heap_get_largest_free_size();
-// an implementation of this function.
-MP_WEAK safe_mode_t port_heap_init(safe_mode_t safe_mode_in) {
-    return safe_mode_in;
 }
 
 void NORETURN nlr_jump_fail(void *val) {

ports/atmel-samd/Makefile

@@ -176,7 +176,10 @@ ifeq ($(GCC_VERSION_GTEQ_11),1)
 CFLAGS += -Wno-stringop-overread -Wno-stringop-overflow
 endif
 
-LDFLAGS = $(CFLAGS) -nostartfiles -Wl,-nostdlib -Wl,-T,$(GENERATED_LD_FILE) -Wl,-Map=$@.map -Wl,-cref -Wl,-gc-sections -specs=nano.specs
+# Somehow the lto doesn't know it needs __ffssi2 until it is too late. (Maybe
+# because the code uses __builtin_ffs().) So, explicitly say we'll need it up
+# front. -u is to say a symbol is undefined from the start.
+LDFLAGS = $(CFLAGS) -u __ffssi2 -nostartfiles -Wl,-nostdlib -Wl,-T,$(GENERATED_LD_FILE) -Wl,-Map=$@.map -Wl,-cref -Wl,-gc-sections -specs=nano.specs
 
 # Use toolchain libm if we're not using our own.
 ifndef INTERNAL_LIBM
@@ -302,6 +305,8 @@ SRC_C += \
 	timer_handler.c \
 	$(SRC_PERIPHERALS) \
 
+$(BUILD)/lib/tlsf/tlsf.o: CFLAGS += -Wno-cast-align
+
 $(BUILD)/lib/tinyusb/src/portable/microchip/samd/dcd_samd.o: CFLAGS += -Wno-missing-prototypes
 
 # This is an OR because it filters to any 1s and then checks to see if it is not

ports/atmel-samd/boards/common.template.ld

@@ -95,13 +95,5 @@ SECTIONS
         _ebss = .;
     } >RAM
 
-    /* this just checks there is enough RAM for the requested stack. */
-    .stack (NOLOAD) :
-    {
-        . = ALIGN(4);
-        . = . + ${CIRCUITPY_DEFAULT_STACK_SIZE};
-        . = ALIGN(4);
-    } >RAM
-
     .ARM.attributes 0 : { *(.ARM.attributes) }
 }

ports/atmel-samd/boards/metro_m0_express/mpconfigboard.h

@@ -8,7 +8,7 @@
 
 #define MICROPY_HW_NEOPIXEL (&pin_PA30)
 
-// Clock rates are off: Salae reads 12MHz which is the limit even though we set it to the safer 8MHz.
+// Clock rates are off: Saleae reads 12MHz which is the limit even though we set it to the safer 8MHz.
 #define SPI_FLASH_BAUDRATE  (8000000)
 
 #define SPI_FLASH_MOSI_PIN          &pin_PB22

ports/atmel-samd/supervisor/port.c

@@ -477,24 +477,21 @@ void reset_cpu(void) {
     reset();
 }
 
-bool port_has_fixed_stack(void) {
-    return false;
-}
-
 uint32_t *port_stack_get_limit(void) {
-    return &_ebss;
+    return port_stack_get_top() - (CIRCUITPY_DEFAULT_STACK_SIZE + CIRCUITPY_EXCEPTION_STACK_SIZE) / sizeof(uint32_t);
 }
 
 uint32_t *port_stack_get_top(void) {
     return &_estack;
 }
 
+// Used for the shared heap allocator.
 uint32_t *port_heap_get_bottom(void) {
-    return port_stack_get_limit();
+    return &_ebss;
 }
 
 uint32_t *port_heap_get_top(void) {
-    return port_stack_get_top();
+    return port_stack_get_limit();
 }
 
 // Place the word to save 8k from the end of RAM so we and the bootloader don't clobber it.

ports/broadcom/Makefile

@@ -127,6 +127,7 @@ endif
 
 CFLAGS += $(INC) -Wall -Werror -std=gnu11 $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS)
 
+$(BUILD)/lib/tlsf/tlsf.o: CFLAGS += -Wno-cast-align
 
 SRC_QSTR += $(SRC_C) $(SRC_SUPERVISOR) $(SRC_COMMON_HAL_EXPANDED) $(SRC_SHARED_MODULE_EXPANDED) $(SRC_CIRCUITPY_COMMON)
 

ports/broadcom/supervisor/port.c

@@ -123,10 +123,6 @@ void reset_cpu(void) {
     }
 }
 
-bool port_has_fixed_stack(void) {
-    return true;
-}
-
 // From the linker script
 extern uint32_t __bss_end;
 extern uint32_t _ld_ram_end;

ports/cxd56/supervisor/port.c

@@ -104,10 +104,6 @@ void reset_to_bootloader(void) {
     }
 }
 
-bool port_has_fixed_stack(void) {
-    return true;
-}
-
 uint32_t *port_stack_get_limit(void) {
     struct tcb_s *rtcb = this_task();
 

ports/espressif/Makefile

@@ -189,6 +189,8 @@ else ifeq ($(IDF_TARGET_ARCH),riscv)
 CFLAGS += -march=rv32imac_zicsr_zifencei
 endif
 
+$(BUILD)/lib/tlsf/tlsf.o: CFLAGS += -Wno-cast-align
+
 LDFLAGS = $(CFLAGS) -Wl,-nostdlib -Wl,-Map=$@.map -Wl,-cref -Wl,--undefined=uxTopUsedPriority
 
 LDFLAGS += \

ports/espressif/bindings/espidf/__init__.c

@@ -141,14 +141,6 @@ STATIC mp_obj_t espidf_get_total_psram(void) {
 }
 MP_DEFINE_CONST_FUN_OBJ_0(espidf_get_total_psram_obj, espidf_get_total_psram);
 
-//| def get_reserved_psram() -> int:
-//|     """Returns number of bytes of psram reserved for use by esp-idf, either a board-specific default value or the value defined in ``settings.toml``."""
-//|
-STATIC mp_obj_t espidf_get_reserved_psram(void) {
-    return MP_OBJ_NEW_SMALL_INT(common_hal_espidf_get_reserved_psram());
-}
-MP_DEFINE_CONST_FUN_OBJ_0(espidf_get_reserved_psram_obj, espidf_get_reserved_psram);
-
 STATIC const mp_rom_map_elem_t espidf_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_espidf) },
 
@@ -159,7 +151,6 @@ STATIC const mp_rom_map_elem_t espidf_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_erase_nvs), MP_ROM_PTR(&espidf_erase_nvs_obj)},
 
     { MP_ROM_QSTR(MP_QSTR_get_total_psram), MP_ROM_PTR(&espidf_get_total_psram_obj)},
-    { MP_ROM_QSTR(MP_QSTR_get_reserved_psram), MP_ROM_PTR(&espidf_get_reserved_psram_obj)},
     { MP_ROM_QSTR(MP_QSTR_IDFError), MP_ROM_PTR(&mp_type_espidf_IDFError) },
     { MP_ROM_QSTR(MP_QSTR_MemoryError),      MP_ROM_PTR(&mp_type_espidf_MemoryError) },
 };

ports/espressif/common-hal/_bleio/ble_events.c

@@ -49,7 +49,7 @@ void ble_event_remove_heap_handlers(void) {
     ble_event_handler_entry_t *it = MP_STATE_VM(ble_event_handler_entries);
     while (it != NULL) {
         // If the param is on the heap, then delete the handler.
-        if (HEAP_PTR(it->param)) {
+        if (gc_ptr_on_heap(it->param)) {
             ble_event_remove_handler(it->func, it->param);
         }
         it = it->next;

ports/espressif/common-hal/espcamera/Camera.c

@@ -77,10 +77,6 @@ void common_hal_espcamera_camera_construct(
     mp_int_t framebuffer_count,
     camera_grab_mode_t grab_mode) {
 
-    if (common_hal_espidf_get_reserved_psram() == 0) {
-        mp_raise_msg(&mp_type_MemoryError, MP_ERROR_TEXT(
-            "espcamera.Camera requires reserved PSRAM to be configured. See the documentation for instructions."));
-    }
     for (int i = 0; i < 8; i++) {
         claim_pin_number(data_pins[i]);
     }

ports/espressif/common-hal/espidf/__init__.c

@@ -25,7 +25,6 @@
  */
 
 #include "bindings/espidf/__init__.h"
-#include "supervisor/memory.h"
 #include "py/runtime.h"
 
 #include "esp_now.h"
@@ -71,36 +70,6 @@ bool common_hal_espidf_set_reserved_psram(size_t amount) {
     #endif
 }
 
-supervisor_allocation *psram_for_idf;
-
-void common_hal_espidf_reserve_psram(void) {
-    #ifdef CONFIG_SPIRAM_USE_MEMMAP
-    if (!psram_for_idf) {
-        ESP_LOGI(TAG, "Reserving %d bytes of psram", reserved_psram);
-        if (reserved_psram == 0) {
-            return;
-        }
-        psram_for_idf = allocate_memory(reserved_psram, true, false);
-        if (psram_for_idf) {
-            intptr_t psram_for_idf_start = (intptr_t)psram_for_idf->ptr;
-            intptr_t psram_for_idf_end = psram_for_idf_start + reserved_psram;
-            ESP_LOGI(TAG, "Reserved %x..%x", psram_for_idf_start, psram_for_idf_end);
-            heap_caps_add_region(psram_for_idf_start, psram_for_idf_end);
-        } else {
-            ESP_LOGE(TAG, "supervisor allocation failed");
-        }
-    }
-    #endif
-}
-
-size_t common_hal_espidf_get_reserved_psram(void) {
-    #ifdef CONFIG_SPIRAM
-    return reserved_psram;
-    #else
-    return 0;
-    #endif
-}
-
 size_t common_hal_espidf_get_total_psram(void) {
     return psram_size_usable();
 }

ports/espressif/esp-idf-config/sdkconfig-psram.defaults

@@ -8,12 +8,6 @@
 # ESP PSRAM
 #
 CONFIG_SPIRAM=y
-#
-# SPI RAM config
-#
-CONFIG_SPIRAM_USE_MEMMAP=y
-# end of SPI RAM config
-
 # end of ESP PSRAM
 
 #

ports/espressif/supervisor/port.c

@@ -55,7 +55,6 @@
 #include "common-hal/socketpool/Socket.h"
 #include "common-hal/wifi/__init__.h"
 #include "supervisor/background_callback.h"
-#include "supervisor/memory.h"
 #include "supervisor/shared/tick.h"
 #include "shared-bindings/microcontroller/__init__.h"
 #include "shared-bindings/microcontroller/RunMode.h"
@@ -321,55 +320,29 @@ safe_mode_t port_init(void) {
     return SAFE_MODE_NONE;
 }
 
-safe_mode_t port_heap_init(safe_mode_t sm) {
+void port_heap_init(void) {
-    mp_int_t reserved = 0;
+    // The IDF sets up the heap, so we don't need to.
-    if (filesystem_present() && common_hal_os_getenv_int("CIRCUITPY_RESERVED_PSRAM", &reserved) == GETENV_OK) {
+}
-        common_hal_espidf_set_reserved_psram(reserved);
-    }
 
-    #if defined(CONFIG_SPIRAM_USE_MEMMAP)
+void *port_malloc(size_t size, bool dma_capable) {
-    {
+    size_t caps = MALLOC_CAP_8BIT;
-        intptr_t heap_start = common_hal_espidf_get_psram_start();
+    if (dma_capable) {
-        intptr_t heap_end = common_hal_espidf_get_psram_end();
+        caps |= MALLOC_CAP_DMA;
-        size_t spiram_size = heap_end - heap_start;
-        if (spiram_size > 0) {
-            heap = (uint32_t *)heap_start;
-            heap_size = (heap_end - heap_start) / sizeof(uint32_t);
-            common_hal_espidf_reserve_psram();
-        } else {
-            ESP_LOGE(TAG, "CONFIG_SPIRAM_USE_MMAP enabled but no spiram heap available");
-        }
     }
-    #elif defined(CONFIG_SPIRAM_USE_CAPS_ALLOC)
+    return heap_caps_malloc(size, caps);
-    {
+}
-        intptr_t psram_start = common_hal_espidf_get_psram_start();
-        intptr_t psram_end = common_hal_espidf_get_psram_end();
-        size_t psram_amount = psram_end - psram_start;
-        size_t biggest_block = heap_caps_get_largest_free_block(MALLOC_CAP_SPIRAM);
-        size_t try_alloc = MIN(biggest_block, psram_amount - common_hal_espidf_get_reserved_psram());
-        heap = heap_caps_malloc(try_alloc, MALLOC_CAP_SPIRAM);
 
-        if (heap) {
+void port_free(void *ptr) {
-            heap_size = try_alloc;
+    heap_caps_free(ptr);
-        } else {
+}
-            ESP_LOGE(TAG, "CONFIG_SPIRAM_USE_CAPS_ALLOC but no spiram heap available");
-        }
-    }
-    #endif
 
-    if (heap == NULL) {
+void port_realloc(void *ptr, size_t size) {
-        size_t heap_total = heap_caps_get_total_size(MALLOC_CAP_8BIT);
+    heap_caps_realloc(ptr, size, MALLOC_CAP_8BIT);
-        heap_size = MIN(heap_caps_get_largest_free_block(MALLOC_CAP_8BIT), heap_total / 2);
+}
-        heap = malloc(heap_size);
-        heap_size = heap_size / sizeof(uint32_t);
-    }
-    if (heap == NULL) {
-        heap_size = 0;
-        return SAFE_MODE_NO_HEAP;
-    }
-
-    return sm;
 
+size_t port_heap_get_largest_free_size(void) {
+    size_t free_size = heap_caps_get_largest_free_block(0);
+    return free_size;
 }
 
 void reset_port(void) {
@@ -455,14 +428,6 @@ void reset_cpu(void) {
     esp_restart();
 }
 
-uint32_t *port_heap_get_bottom(void) {
-    return heap;
-}
-
-uint32_t *port_heap_get_top(void) {
-    return heap + heap_size;
-}
-
 uint32_t *port_stack_get_limit(void) {
     #pragma GCC diagnostic push
     #pragma GCC diagnostic ignored "-Wcast-align"
@@ -485,10 +450,6 @@ uint32_t *port_stack_get_top(void) {
     return port_stack_get_limit() + ESP_TASK_MAIN_STACK / (sizeof(uint32_t) / sizeof(StackType_t));
 }
 
-bool port_has_fixed_stack(void) {
-    return true;
-}
-
 void port_set_saved_word(uint32_t value) {
     REG_WRITE(CP_SAVED_WORD_REGISTER, value);
 }

ports/litex/Makefile

@@ -106,6 +106,7 @@ SRC_SHARED_MODULE_EXPANDED = $(addprefix shared-bindings/, $(SRC_SHARED_MODULE))
                              $(addprefix shared-module/, $(SRC_SHARED_MODULE)) \
                              $(addprefix shared-module/, $(SRC_SHARED_MODULE_INTERNAL))
 
+$(BUILD)/lib/tlsf/tlsf.o: CFLAGS += -Wno-cast-align
 
 ifneq ($(FROZEN_MPY_DIR),)
 FROZEN_MPY_PY_FILES := $(shell find -L $(FROZEN_MPY_DIR) -type f -name '*.py')

ports/litex/supervisor/port.c

@@ -101,20 +101,19 @@ void reset_cpu(void) {
     for (;;) {}
 }
 
-bool port_has_fixed_stack(void) {
-    return false;
-}
-
 uint32_t *port_heap_get_bottom(void) {
-    return port_stack_get_limit();
+    return &_ebss;
 }
 
 uint32_t *port_heap_get_top(void) {
-    return port_stack_get_top();
+    return port_stack_get_limit();
 }
 
 uint32_t *port_stack_get_limit(void) {
-    return &_ebss;
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Warray-bounds"
+    return port_stack_get_top() - (CIRCUITPY_DEFAULT_STACK_SIZE + CIRCUITPY_EXCEPTION_STACK_SIZE) / sizeof(uint32_t);
+    #pragma GCC diagnostic pop
 }
 
 uint32_t *port_stack_get_top(void) {

ports/mimxrt10xx/Makefile

@@ -89,6 +89,8 @@ ifeq ($(CIRCUITPY_SWO_TRACE), 1)
   CFLAGS += -finstrument-functions -finstrument-functions-exclude-file-list=tinyusb -finstrument-functions-exclude-function-list='USB_OTG1_IRQHandler,usb_irq_handler,nlr_push,CLOCK_EnableClock,CLOCK_SetDiv,CLOCK_SetMux,__DMB,__ISB,__DSB,SCB_EnableICache,SCB_EnableDCache,ARM_MPU_Disable,ARM_MPU_Enable,SCB_DisableDCache,SCB_DisableICache,__enable_irq,__disable_irq,__set_MSP,port_get_raw_ticks,supervisor_ticks_ms64'
 endif
 
+$(BUILD)/lib/tlsf/tlsf.o: CFLAGS += -Wno-cast-align
+
 LD_FILES = $(wildcard boards/$(BOARD)/*.ld) $(addprefix linking/, flash/$(FLASH).ld chip_family/$(CHIP_FAMILY).ld common.ld)
 
 LD_SCRIPT_FLAG := -Wl,-T,

ports/mimxrt10xx/supervisor/port.c

@@ -499,10 +499,6 @@ uint32_t *port_stack_get_top(void) {
     return &_ld_stack_top;
 }
 
-bool port_has_fixed_stack(void) {
-    return true;
-}
-
 uint32_t *port_heap_get_bottom(void) {
     return &_ld_heap_start;
 }

ports/nrf/bluetooth/ble_drv.c

@@ -61,7 +61,7 @@ void ble_drv_remove_heap_handlers(void) {
     ble_drv_evt_handler_entry_t *it = MP_STATE_VM(ble_drv_evt_handler_entries);
     while (it != NULL) {
         // If the param is on the heap, then delete the handler.
-        if (HEAP_PTR(it->param)) {
+        if (gc_ptr_on_heap(it->param)) {
             ble_drv_remove_event_handler(it->func, it->param);
         }
         it = it->next;

ports/nrf/boards/bluemicro833/mpconfigboard.mk

@@ -16,3 +16,7 @@ CIRCUITPY_ONEWIREIO = 0
 CIRCUITPY_PIXELBUF = 1
 CIRCUITPY_PIXELMAP = 0
 CIRCUITPY_TOUCHIO = 0
+
+# Features to disable
+CIRCUITPY_SAFEMODE_PY = 0
+CIRCUITPY_OPT_LOAD_ATTR_FAST_PATH = 0

ports/nrf/supervisor/port.c

@@ -286,15 +286,14 @@ uint32_t *port_heap_get_bottom(void) {
 }
 
 uint32_t *port_heap_get_top(void) {
-    return port_stack_get_top();
+    return port_stack_get_limit();
-}
-
-bool port_has_fixed_stack(void) {
-    return false;
 }
 
 uint32_t *port_stack_get_limit(void) {
-    return &_euninitialized;
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Warray-bounds"
+    return port_stack_get_top() - (CIRCUITPY_DEFAULT_STACK_SIZE + CIRCUITPY_EXCEPTION_STACK_SIZE) / sizeof(uint32_t);
+    #pragma GCC diagnostic pop
 }
 
 uint32_t *port_stack_get_top(void) {

ports/raspberrypi/Makefile

@@ -173,7 +173,7 @@ endif
 # Remove -Wno-stringop-overflow after we can test with CI's GCC 10. Mac's looks weird.
 DISABLE_WARNINGS = -Wno-stringop-overflow -Wno-cast-align
 
-CFLAGS += $(INC) -Wall -Werror -std=gnu11 -nostdlib -fshort-enums $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS) -Werror=missing-prototypes
+CFLAGS += $(INC) -Wall -Werror -std=gnu11 -fshort-enums $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS) -Werror=missing-prototypes
 
 CFLAGS += \
 	-march=armv6-m \

ports/raspberrypi/common-hal/picodvi/Framebuffer.c

@@ -31,6 +31,7 @@
 #include "shared-bindings/time/__init__.h"
 #include "common-hal/pwmio/PWMOut.h"
 #include "common-hal/rp2pio/StateMachine.h"
+#include "supervisor/port.h"
 
 #include "src/common/pico_stdlib/include/pico/stdlib.h"
 #include "src/rp2040/hardware_structs/include/hardware/structs/mpu.h"
@@ -123,8 +124,6 @@ static void __not_in_flash_func(core1_scanline_callback)(void) {
     self->next_scanline += 1;
     if (self->next_scanline >= self->height) {
         self->next_scanline = 0;
-        // Update the framebuffer pointer in case it moved.
-        self->framebuffer = self->allocation->ptr;
     }
 }
 
@@ -243,8 +242,8 @@ void common_hal_picodvi_framebuffer_construct(picodvi_framebuffer_obj_t *self,
     size_t framebuffer_size = self->pitch * self->height;
     self->tmdsbuf_size = tmds_bufs_per_scanline * scanline_width / DVI_SYMBOLS_PER_WORD + 1;
     size_t total_allocation_size = sizeof(uint32_t) * (framebuffer_size + DVI_N_TMDS_BUFFERS * self->tmdsbuf_size);
-    self->allocation = allocate_memory(total_allocation_size, false, true);
+    self->framebuffer = (uint32_t *)port_malloc(total_allocation_size, true);
-    if (self->allocation == NULL) {
+    if (self->framebuffer == NULL) {
         m_malloc_fail(total_allocation_size);
         return;
     }
@@ -270,7 +269,6 @@ void common_hal_picodvi_framebuffer_construct(picodvi_framebuffer_obj_t *self,
     // For the output.
     user_irq_claim(DMA_IRQ_1);
     self->framebuffer_len = framebuffer_size;
-    self->framebuffer = self->allocation->ptr;
     self->color_depth = color_depth;
 
     self->dvi.timing = timing;
@@ -383,7 +381,7 @@ void common_hal_picodvi_framebuffer_deinit(picodvi_framebuffer_obj_t *self) {
 
     active_picodvi = NULL;
 
-    free_memory(self->allocation);
+    port_free(self->framebuffer);
     self->framebuffer = NULL;
 
     self->base.type = &mp_type_NoneType;

ports/raspberrypi/common-hal/picodvi/Framebuffer.h

@@ -28,13 +28,10 @@
 
 #include "py/obj.h"
 
-#include "supervisor/memory.h"
-
 #include "lib/PicoDVI/software/libdvi/dvi.h"
 
 typedef struct {
     mp_obj_base_t base;
-    supervisor_allocation *allocation;
     uint32_t *framebuffer;
     size_t framebuffer_len; // in words
     size_t tmdsbuf_size; // in words

ports/raspberrypi/supervisor/port.c

@@ -233,15 +233,15 @@ void reset_cpu(void) {
     }
 }
 
-bool port_has_fixed_stack(void) {
-    return false;
-}
-
 // From the linker script
 extern uint32_t _ld_cp_dynamic_mem_start;
 extern uint32_t _ld_cp_dynamic_mem_end;
 uint32_t *port_stack_get_limit(void) {
-    return &_ld_cp_dynamic_mem_start;
+    #pragma GCC diagnostic push
+
+    #pragma GCC diagnostic ignored "-Warray-bounds"
+    return port_stack_get_top() - (CIRCUITPY_DEFAULT_STACK_SIZE + CIRCUITPY_EXCEPTION_STACK_SIZE) / sizeof(uint32_t);
+    #pragma GCC diagnostic pop
 }
 
 uint32_t *port_stack_get_top(void) {
@@ -249,11 +249,11 @@ uint32_t *port_stack_get_top(void) {
 }
 
 uint32_t *port_heap_get_bottom(void) {
-    return port_stack_get_limit();
+    return &_ld_cp_dynamic_mem_start;
 }
 
 uint32_t *port_heap_get_top(void) {
-    return port_stack_get_top();
+    return port_stack_get_limit();
 }
 
 uint32_t __uninitialized_ram(saved_word);

ports/silabs/supervisor/port.c

@@ -218,10 +218,6 @@ uint32_t *port_heap_get_top(void) {
     return heap + heap_size;
 }
 
-bool port_has_fixed_stack(void) {
-    return true;
-}
-
 uint32_t *port_stack_get_limit(void) {
     #pragma GCC diagnostic push
     #pragma GCC diagnostic ignored "-Wcast-align"

ports/stm/common-hal/audiobusio/PDMIn.c

@@ -29,7 +29,6 @@
 #include "shared-bindings/audiobusio/PDMIn.h"
 #include "shared-bindings/microcontroller/Pin.h"
 #include "py/runtime.h"
-#include "supervisor/memory.h"
 #include "MEMS_Audio_ll_stm32l4.h"
 
 

ports/stm/common-hal/audiobusio/PDMIn.h

@@ -30,7 +30,6 @@
 #include <stdint.h>
 #include "py/obj.h"
 #include "peripherals/pins.h"
-#include "supervisor/memory.h"
 
 typedef struct MemsAudio_t MemsAudio;
 typedef struct MemsAudio_STM32L4SAIPDM_t MemsAudio_STM32L4SAIPDM;
@@ -43,7 +42,6 @@ typedef struct {
     uint8_t bit_depth;
     bool mono;
     uint8_t oversample;
-    supervisor_allocation *audio_allocation;
     MemsAudio *audio;
     MemsAudio_STM32L4SAIPDM *audio_impl;
     /**

ports/stm/supervisor/port.c

@@ -330,15 +330,15 @@ uint32_t *port_heap_get_bottom(void) {
 }
 
 uint32_t *port_heap_get_top(void) {
-    return &_ld_heap_end;
+    return port_stack_get_limit();
-}
-
-bool port_has_fixed_stack(void) {
-    return false;
 }
 
 uint32_t *port_stack_get_limit(void) {
-    return &_ld_stack_bottom;
+    #pragma GCC diagnostic push
+
+    #pragma GCC diagnostic ignored "-Warray-bounds"
+    return port_stack_get_top() - (CIRCUITPY_DEFAULT_STACK_SIZE + CIRCUITPY_EXCEPTION_STACK_SIZE) / sizeof(uint32_t);
+    #pragma GCC diagnostic pop
 }
 
 uint32_t *port_stack_get_top(void) {

py/circuitpy_defns.mk

@@ -779,6 +779,7 @@ SRC_LIBM = \
 $(addprefix lib/,\
 	libm/math.c \
 	libm/roundf.c \
+	libm/fabsf.c \
 	libm/fmodf.c \
 	libm/nearbyintf.c \
 	libm/ef_sqrt.c \

py/circuitpy_mpconfig.h

@@ -91,6 +91,11 @@ extern void common_hal_mcu_enable_interrupts(void);
 #define MICROPY_FLOAT_HIGH_QUALITY_HASH  (0)
 #define MICROPY_FLOAT_IMPL               (MICROPY_FLOAT_IMPL_FLOAT)
 #define MICROPY_GC_ALLOC_THRESHOLD       (0)
+#define MICROPY_GC_SPLIT_HEAP            (1)
+#define MICROPY_GC_SPLIT_HEAP_AUTO       (1)
+#define MP_PLAT_ALLOC_HEAP(size) port_malloc(size, true)
+#define MP_PLAT_FREE_HEAP(ptr) port_free(ptr)
+#include "supervisor/port_heap.h"
 #define MICROPY_HELPER_LEXER_UNIX        (0)
 #define MICROPY_HELPER_REPL              (1)
 #define MICROPY_KBD_EXCEPTION            (1)
@@ -155,7 +160,6 @@ extern void common_hal_mcu_enable_interrupts(void);
 #define MICROPY_QSTR_BYTES_IN_HASH       (1)
 #define MICROPY_REPL_AUTO_INDENT         (1)
 #define MICROPY_REPL_EVENT_DRIVEN        (0)
-#define CIRCUITPY_SETTABLE_PYSTACK       (1)
 #define MICROPY_STACK_CHECK              (1)
 #define MICROPY_STREAMS_NON_BLOCK        (1)
 #ifndef MICROPY_USE_INTERNAL_PRINTF
@@ -431,6 +435,18 @@ void background_callback_run_all(void);
 #define CIRCUITPY_PYSTACK_SIZE 1536
 #endif
 
+// The VM heap starts at this size and doubles in size as needed until it runs
+// out of memory in the outer heap. Once it can't double, it'll then grow into
+// the largest contiguous free area.
+#ifndef CIRCUITPY_HEAP_START_SIZE
+#define CIRCUITPY_HEAP_START_SIZE (8 * 1024)
+#endif
+
+// How much of the c stack we leave to ensure we can process exceptions.
+#ifndef CIRCUITPY_EXCEPTION_STACK_SIZE
+#define CIRCUITPY_EXCEPTION_STACK_SIZE 1024
+#endif
+
 // Wait this long before sleeping immediately after startup, to see if we are connected via USB or BLE.
 #ifndef CIRCUITPY_WORKFLOW_CONNECTION_SLEEP_DELAY
 #define CIRCUITPY_WORKFLOW_CONNECTION_SLEEP_DELAY 5

py/gc.c

@@ -338,16 +338,13 @@ STATIC bool gc_try_add_heap(size_t failed_alloc) {
 
 #endif
 
-#if !MICROPY_GC_SPLIT_HEAP
 // CIRCUITPY-CHANGE
-// TODO FOR MERGE: fix this for split heap
 void gc_deinit(void) {
-    // Run any finalisers before we stop using the heap.
+    // Run any finalisers before we stop using the heap. This will also free
+    // any additional heap areas (but not the first.)
     gc_sweep_all();
-    /// MP_STATIC_ASSERT(!MICROPY_GC_SPLIT_HEAP);
     memset(&MP_STATE_MEM(area), 0, sizeof(MP_STATE_MEM(area)));
 }
-#endif
 
 void gc_lock(void) {
     // This does not need to be atomic or have the GC mutex because:
@@ -366,6 +363,17 @@ bool gc_is_locked(void) {
     return MP_STATE_THREAD(gc_lock_depth) != 0;
 }
 
+// CIRCUITPY-CHANGE
+bool gc_ptr_on_heap(void *ptr) {
+    for (mp_state_mem_area_t *area = &MP_STATE_MEM(area); area != NULL; area = NEXT_AREA(area)) {
+        if (ptr >= (void *)area->gc_pool_start   // must be above start of pool
+            && ptr < (void *)area->gc_pool_end) {   // must be below end of pool
+            return true;
+        }
+    }
+    return false;
+}
+
 #if MICROPY_GC_SPLIT_HEAP
 // Returns the area to which this pointer belongs, or NULL if it isn't
 // allocated on the GC-managed heap.
@@ -383,7 +391,12 @@ STATIC inline mp_state_mem_area_t *gc_get_ptr_area(const void *ptr) {
 }
 #endif
 
-// CIRCUITPY-CHANGE: VERIFY_PTR moved to gc.h to make it available elsewhere.
+// ptr should be of type void*
+#define VERIFY_PTR(ptr) ( \
+    ((uintptr_t)(ptr) & (BYTES_PER_BLOCK - 1)) == 0          /* must be aligned on a block */ \
+    && ptr >= (void *)MP_STATE_MEM(area).gc_pool_start      /* must be above start of pool */ \
+    && ptr < (void *)MP_STATE_MEM(area).gc_pool_end         /* must be below end of pool */ \
+    )
 
 #ifndef TRACE_MARK
 #if DEBUG_PRINT
@@ -837,6 +850,10 @@ void *gc_alloc(size_t n_bytes, unsigned int alloc_flags) {
                 continue;
             }
             #endif
+
+            #if CIRCUITPY_DEBUG
+            gc_dump_alloc_table(&mp_plat_print);
+            #endif
             return NULL;
         }
         DEBUG_printf("gc_alloc(" UINT_FMT "): no free mem, triggering GC\n", n_bytes);
@@ -963,7 +980,7 @@ void gc_free(void *ptr) {
     // assert(area);
     #else
     // CIRCUITPY-CHANGE: extra checking
-    if (MP_STATE_MEM(area.gc_pool_start) == 0) {
+    if (MP_STATE_MEM(area).gc_pool_start == 0) {
         reset_into_safe_mode(SAFE_MODE_GC_ALLOC_OUTSIDE_VM);
     }
     assert(VERIFY_PTR(ptr));
@@ -1245,39 +1262,6 @@ void *gc_realloc(void *ptr_in, size_t n_bytes, bool allow_move) {
 }
 #endif // Alternative gc_realloc impl
 
-// CIRCUITPY-CHANGE
-bool gc_never_free(void *ptr) {
-    // Check to make sure the pointer is on the heap in the first place.
-    if (gc_nbytes(ptr) == 0) {
-        return false;
-    }
-    // Pointers are stored in a linked list where each block is BYTES_PER_BLOCK long and the first
-    // pointer is the next block of pointers.
-    void **current_reference_block = MP_STATE_MEM(permanent_pointers);
-    void **last_reference_block = NULL;
-    while (current_reference_block != NULL) {
-        for (size_t i = 1; i < BYTES_PER_BLOCK / sizeof(void *); i++) {
-            if (current_reference_block[i] == NULL) {
-                current_reference_block[i] = ptr;
-                return true;
-            }
-        }
-        last_reference_block = current_reference_block; // keep a record of last "proper" reference block
-        current_reference_block = current_reference_block[0];
-    }
-    void **next_block = gc_alloc(BYTES_PER_BLOCK, false);
-    if (next_block == NULL) {
-        return false;
-    }
-    if (MP_STATE_MEM(permanent_pointers) == NULL) {
-        MP_STATE_MEM(permanent_pointers) = next_block;
-    } else {
-        last_reference_block[0] = next_block;
-    }
-    next_block[1] = ptr;
-    return true;
-}
-
 void gc_dump_info(const mp_print_t *print) {
     gc_info_t info;
     gc_info(&info);
@@ -1421,8 +1405,6 @@ void gc_dump_alloc_table(const mp_print_t *print) {
         }
         mp_print_str(print, "\n");
     }
-    // CIRCUITPY-CHANGE
-    mp_print_str(&mp_plat_print, "\n");
     GC_EXIT();
 }
 

py/gc.h

@@ -34,22 +34,6 @@
 #include "py/mpstate.h"
 #include "py/misc.h"
 
-// CIRCUITPY-CHANGE: - this may change when use split heap
-#if !MICROPY_GC_SPLIT_HEAP
-#define HEAP_PTR(ptr) ( \
-    MP_STATE_MEM(area).gc_pool_start != 0                     /* Not on the heap if it isn't inited */ \
-    && ptr >= (void *)MP_STATE_MEM(area).gc_pool_start        /* must be above start of pool */ \
-    && ptr < (void *)MP_STATE_MEM(area).gc_pool_end           /* must be below end of pool */ \
-    )
-
-// CIRCUITPY-CHANGE: defined here so available outside of gc.c
-// ptr should be of type void*
-#define VERIFY_PTR(ptr) ( \
-    ((uintptr_t)(ptr) & (MICROPY_BYTES_PER_GC_BLOCK - 1)) == 0          /* must be aligned on a block */ \
-    && HEAP_PTR(ptr) \
-    )
-#endif
-
 void gc_init(void *start, void *end);
 // CIRCUITPY-CHANGE
 void gc_deinit(void);
@@ -101,6 +85,11 @@ void *gc_realloc(void *ptr, size_t n_bytes, bool allow_move);
 // very sparingly because it can leak memory.
 bool gc_never_free(void *ptr);
 
+// CIRCUITPY-CHANGE
+// True if the pointer is on the MP heap. Doesn't require that it is the start
+// of a block.
+bool gc_ptr_on_heap(void *ptr);
+
 typedef struct _gc_info_t {
     size_t total;
     size_t used;

shared-bindings/__future__/__init__.c

@@ -38,7 +38,7 @@
 //| """
 //|
 //| annotations: Any
-//| """In CPython, ``from __future import annotations``
+//| """In CPython, ``from __future__ import annotations``
 //| indicates that evaluation of annotations is postponed, as described in PEP 563.
 //| CircuitPython (and MicroPython) ignore annotations entirely, whether or not this feature is imported.
 //| This is a limitation of CircuitPython and MicroPython for efficiency reasons.

shared-bindings/displayio/__init__.h

@@ -66,3 +66,4 @@ typedef bool (*display_bus_begin_transaction)(mp_obj_t bus);
 typedef void (*display_bus_send)(mp_obj_t bus, display_byte_type_t byte_type,
     display_chip_select_behavior_t chip_select, const uint8_t *data, uint32_t data_length);
 typedef void (*display_bus_end_transaction)(mp_obj_t bus);
+typedef void (*display_bus_collect_ptrs)(mp_obj_t bus);

shared-bindings/fourwire/FourWire.h

@@ -51,3 +51,7 @@ void common_hal_fourwire_fourwire_send(mp_obj_t self, display_byte_type_t byte_t
     display_chip_select_behavior_t chip_select, const uint8_t *data, uint32_t data_length);
 
 void common_hal_fourwire_fourwire_end_transaction(mp_obj_t self);
+
+// The FourWire object always lives off the MP heap. So, code must collect any pointers
+// back to the MP heap manually. Otherwise they'll get freed.
+void common_hal_fourwire_fourwire_collect_ptrs(mp_obj_t obj);

shared-bindings/i2cdisplaybus/I2CDisplayBus.h

@@ -47,3 +47,7 @@ void common_hal_i2cdisplaybus_i2cdisplaybus_send(mp_obj_t self, display_byte_typ
     display_chip_select_behavior_t chip_select, const uint8_t *data, uint32_t data_length);
 
 void common_hal_i2cdisplaybus_i2cdisplaybus_end_transaction(mp_obj_t self);
+
+// The I2CDisplayBus object always lives off the MP heap. So, code must collect any pointers
+// back to the MP heap manually. Otherwise they'll get freed.
+void common_hal_i2cdisplaybus_i2cdisplaybus_collect_ptrs(mp_obj_t obj);

shared-bindings/is31fl3741/FrameBuffer.c

@@ -71,7 +71,7 @@
 //|         :param bool scale: if True display is scaled down by 3 when displayed
 //|         :param bool gamma: if True apply gamma correction to all LEDs"""
 //|         ...
-STATIC mp_obj_t is31fl3741_FrameBuffer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
+STATIC mp_obj_t is31fl3741_framebuffer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
     enum { ARG_is31, ARG_width, ARG_height, ARG_mapping, ARG_framebuffer, ARG_scale, ARG_gamma };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_is31, MP_ARG_OBJ | MP_ARG_REQUIRED },
@@ -85,8 +85,8 @@ STATIC mp_obj_t is31fl3741_FrameBuffer_make_new(const mp_obj_type_t *type, size_
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
-    is31fl3741_FrameBuffer_obj_t *self = &allocate_display_bus_or_raise()->is31fl3741;
+    is31fl3741_framebuffer_obj_t *self = &allocate_display_bus_or_raise()->is31fl3741;
-    self->base.type = &is31fl3741_FrameBuffer_type;
+    self->base.type = &is31fl3741_framebuffer_type;
 
     if (args[ARG_width].u_int <= 0) {
         mp_raise_ValueError(MP_ERROR_TEXT("width must be greater than zero"));
@@ -115,7 +115,7 @@ STATIC mp_obj_t is31fl3741_FrameBuffer_make_new(const mp_obj_type_t *type, size_
         framebuffer = mp_obj_new_bytearray_of_zeros(bufsize);
     }
 
-    common_hal_is31fl3741_FrameBuffer_construct(self,
+    common_hal_is31fl3741_framebuffer_construct(self,
         args[ARG_width].u_int,
         args[ARG_height].u_int,
         framebuffer,
@@ -131,14 +131,14 @@ STATIC mp_obj_t is31fl3741_FrameBuffer_make_new(const mp_obj_type_t *type, size_
 //|         IS31FL3741 instance.  After deinitialization, no further operations
 //|         may be performed."""
 //|         ...
-STATIC mp_obj_t is31fl3741_FrameBuffer_deinit(mp_obj_t self_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_deinit(mp_obj_t self_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
-    common_hal_is31fl3741_FrameBuffer_deinit(self);
+    common_hal_is31fl3741_framebuffer_deinit(self);
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_FrameBuffer_deinit_obj, is31fl3741_FrameBuffer_deinit);
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_framebuffer_deinit_obj, is31fl3741_framebuffer_deinit);
 
-static void check_for_deinit(is31fl3741_FrameBuffer_obj_t *self) {
+static void check_for_deinit(is31fl3741_framebuffer_obj_t *self) {
     if (self->framebuffer == NULL) {
         raise_deinited_error();
     }
@@ -147,18 +147,18 @@ static void check_for_deinit(is31fl3741_FrameBuffer_obj_t *self) {
 //|     brightness: float
 //|     """In the current implementation, 0.0 turns the display off entirely
 //|     and any other value up to 1.0 turns the display on fully."""
-STATIC mp_obj_t is31fl3741_FrameBuffer_get_brightness(mp_obj_t self_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_get_brightness(mp_obj_t self_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
     uint8_t current = common_hal_is31fl3741_get_current(self->is31fl3741);
 
     float brightness = (float)current / (float)0xFF;
     return mp_obj_new_float(brightness);
 }
-MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_FrameBuffer_get_brightness_obj, is31fl3741_FrameBuffer_get_brightness);
+MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_framebuffer_get_brightness_obj, is31fl3741_framebuffer_get_brightness);
 
-STATIC mp_obj_t is31fl3741_FrameBuffer_set_brightness(mp_obj_t self_in, mp_obj_t value_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_set_brightness(mp_obj_t self_in, mp_obj_t value_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
     mp_float_t brightness = mp_obj_get_float(value_in);
     if (brightness < 0.0f || brightness > 1.0f) {
@@ -170,119 +170,119 @@ STATIC mp_obj_t is31fl3741_FrameBuffer_set_brightness(mp_obj_t self_in, mp_obj_t
 
     return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_2(is31fl3741_FrameBuffer_set_brightness_obj, is31fl3741_FrameBuffer_set_brightness);
+MP_DEFINE_CONST_FUN_OBJ_2(is31fl3741_framebuffer_set_brightness_obj, is31fl3741_framebuffer_set_brightness);
 
-MP_PROPERTY_GETSET(is31fl3741_FrameBuffer_brightness_obj,
+MP_PROPERTY_GETSET(is31fl3741_framebuffer_brightness_obj,
-    (mp_obj_t)&is31fl3741_FrameBuffer_get_brightness_obj,
+    (mp_obj_t)&is31fl3741_framebuffer_get_brightness_obj,
-    (mp_obj_t)&is31fl3741_FrameBuffer_set_brightness_obj);
+    (mp_obj_t)&is31fl3741_framebuffer_set_brightness_obj);
 
 //|     def refresh(self) -> None:
 //|         """Transmits the color data in the buffer to the pixels so that
 //|         they are shown."""
 //|         ...
-STATIC mp_obj_t is31fl3741_FrameBuffer_refresh(mp_obj_t self_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_refresh(mp_obj_t self_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
-    common_hal_is31fl3741_FrameBuffer_refresh(self, 0);
+    common_hal_is31fl3741_framebuffer_refresh(self, 0);
     return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_FrameBuffer_refresh_obj, is31fl3741_FrameBuffer_refresh);
+MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_framebuffer_refresh_obj, is31fl3741_framebuffer_refresh);
 
 //|     width: int
 //|     """The width of the display, in pixels"""
-STATIC mp_obj_t is31fl3741_FrameBuffer_get_width(mp_obj_t self_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_get_width(mp_obj_t self_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
-    return MP_OBJ_NEW_SMALL_INT(common_hal_is31fl3741_FrameBuffer_get_width(self));
+    return MP_OBJ_NEW_SMALL_INT(common_hal_is31fl3741_framebuffer_get_width(self));
 }
-MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_FrameBuffer_get_width_obj, is31fl3741_FrameBuffer_get_width);
+MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_framebuffer_get_width_obj, is31fl3741_framebuffer_get_width);
-MP_PROPERTY_GETTER(is31fl3741_FrameBuffer_width_obj,
+MP_PROPERTY_GETTER(is31fl3741_framebuffer_width_obj,
-    (mp_obj_t)&is31fl3741_FrameBuffer_get_width_obj);
+    (mp_obj_t)&is31fl3741_framebuffer_get_width_obj);
 
 //|     height: int
 //|     """The height of the display, in pixels"""
 //|
-STATIC mp_obj_t is31fl3741_FrameBuffer_get_height(mp_obj_t self_in) {
+STATIC mp_obj_t is31fl3741_framebuffer_get_height(mp_obj_t self_in) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
-    return MP_OBJ_NEW_SMALL_INT(common_hal_is31fl3741_FrameBuffer_get_height(self));
+    return MP_OBJ_NEW_SMALL_INT(common_hal_is31fl3741_framebuffer_get_height(self));
 }
-MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_FrameBuffer_get_height_obj, is31fl3741_FrameBuffer_get_height);
+MP_DEFINE_CONST_FUN_OBJ_1(is31fl3741_framebuffer_get_height_obj, is31fl3741_framebuffer_get_height);
-MP_PROPERTY_GETTER(is31fl3741_FrameBuffer_height_obj,
+MP_PROPERTY_GETTER(is31fl3741_framebuffer_height_obj,
-    (mp_obj_t)&is31fl3741_FrameBuffer_get_height_obj);
+    (mp_obj_t)&is31fl3741_framebuffer_get_height_obj);
 
-STATIC const mp_rom_map_elem_t is31fl3741_FrameBuffer_locals_dict_table[] = {
+STATIC const mp_rom_map_elem_t is31fl3741_framebuffer_locals_dict_table[] = {
-    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&is31fl3741_FrameBuffer_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&is31fl3741_framebuffer_deinit_obj) },
-    { MP_ROM_QSTR(MP_QSTR_brightness), MP_ROM_PTR(&is31fl3741_FrameBuffer_brightness_obj) },
+    { MP_ROM_QSTR(MP_QSTR_brightness), MP_ROM_PTR(&is31fl3741_framebuffer_brightness_obj) },
-    { MP_ROM_QSTR(MP_QSTR_refresh), MP_ROM_PTR(&is31fl3741_FrameBuffer_refresh_obj) },
+    { MP_ROM_QSTR(MP_QSTR_refresh), MP_ROM_PTR(&is31fl3741_framebuffer_refresh_obj) },
-    { MP_ROM_QSTR(MP_QSTR_width), MP_ROM_PTR(&is31fl3741_FrameBuffer_width_obj) },
+    { MP_ROM_QSTR(MP_QSTR_width), MP_ROM_PTR(&is31fl3741_framebuffer_width_obj) },
-    { MP_ROM_QSTR(MP_QSTR_height), MP_ROM_PTR(&is31fl3741_FrameBuffer_height_obj) },
+    { MP_ROM_QSTR(MP_QSTR_height), MP_ROM_PTR(&is31fl3741_framebuffer_height_obj) },
 };
-STATIC MP_DEFINE_CONST_DICT(is31fl3741_FrameBuffer_locals_dict, is31fl3741_FrameBuffer_locals_dict_table);
+STATIC MP_DEFINE_CONST_DICT(is31fl3741_framebuffer_locals_dict, is31fl3741_framebuffer_locals_dict_table);
 
-STATIC void is31fl3741_FrameBuffer_get_bufinfo(mp_obj_t self_in, mp_buffer_info_t *bufinfo) {
+STATIC void is31fl3741_framebuffer_get_bufinfo(mp_obj_t self_in, mp_buffer_info_t *bufinfo) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     check_for_deinit(self);
 
     *bufinfo = self->bufinfo;
 }
 
-STATIC void is31fl3741_FrameBuffer_swapbuffers(mp_obj_t self_in, uint8_t *dirty_row_bitmap) {
+STATIC void is31fl3741_framebuffer_swapbuffers(mp_obj_t self_in, uint8_t *dirty_row_bitmap) {
-    common_hal_is31fl3741_FrameBuffer_refresh(self_in, dirty_row_bitmap);
+    common_hal_is31fl3741_framebuffer_refresh(self_in, dirty_row_bitmap);
 }
 
-STATIC void is31fl3741_FrameBuffer_deinit_proto(mp_obj_t self_in) {
+STATIC void is31fl3741_framebuffer_deinit_proto(mp_obj_t self_in) {
-    common_hal_is31fl3741_FrameBuffer_deinit(self_in);
+    common_hal_is31fl3741_framebuffer_deinit(self_in);
 }
 
-STATIC float is31fl3741_FrameBuffer_get_brightness_proto(mp_obj_t self_in) {
+STATIC float is31fl3741_framebuffer_get_brightness_proto(mp_obj_t self_in) {
-    return common_hal_is31fl3741_FrameBuffer_get_paused(self_in) ? 0.0f : 1.0f;
+    return common_hal_is31fl3741_framebuffer_get_paused(self_in) ? 0.0f : 1.0f;
 }
 
-STATIC bool is31fl3741_FrameBuffer_set_brightness_proto(mp_obj_t self_in, mp_float_t value) {
+STATIC bool is31fl3741_framebuffer_set_brightness_proto(mp_obj_t self_in, mp_float_t value) {
-    common_hal_is31fl3741_FrameBuffer_set_paused(self_in, value <= 0);
+    common_hal_is31fl3741_framebuffer_set_paused(self_in, value <= 0);
     return true;
 }
 
-STATIC int is31fl3741_FrameBuffer_get_width_proto(mp_obj_t self_in) {
+STATIC int is31fl3741_framebuffer_get_width_proto(mp_obj_t self_in) {
-    return common_hal_is31fl3741_FrameBuffer_get_width(self_in);
+    return common_hal_is31fl3741_framebuffer_get_width(self_in);
 }
 
-STATIC int is31fl3741_FrameBuffer_get_height_proto(mp_obj_t self_in) {
+STATIC int is31fl3741_framebuffer_get_height_proto(mp_obj_t self_in) {
-    return common_hal_is31fl3741_FrameBuffer_get_height(self_in);
+    return common_hal_is31fl3741_framebuffer_get_height(self_in);
 }
 
-STATIC int is31fl3741_FrameBuffer_get_color_depth_proto(mp_obj_t self_in) {
+STATIC int is31fl3741_framebuffer_get_color_depth_proto(mp_obj_t self_in) {
     // The way displayio works depth is used to calculate bytes
     // We use an uint32_t for color already so setting to 24 causes
     // more changes required
     return 32;
 }
 
-STATIC int is31fl3741_FrameBuffer_get_bytes_per_cell_proto(mp_obj_t self_in) {
+STATIC int is31fl3741_framebuffer_get_bytes_per_cell_proto(mp_obj_t self_in) {
     return 1;
 }
 
-STATIC int is31fl3741_FrameBuffer_get_native_frames_per_second_proto(mp_obj_t self_in) {
+STATIC int is31fl3741_framebuffer_get_native_frames_per_second_proto(mp_obj_t self_in) {
     return 60; // This was just chosen may vary based on LEDs used?
 }
 
-STATIC const framebuffer_p_t is31fl3741_FrameBuffer_proto = {
+STATIC const framebuffer_p_t is31fl3741_framebuffer_proto = {
     MP_PROTO_IMPLEMENT(MP_QSTR_protocol_framebuffer)
-    .get_bufinfo = is31fl3741_FrameBuffer_get_bufinfo,
+    .get_bufinfo = is31fl3741_framebuffer_get_bufinfo,
-    .set_brightness = is31fl3741_FrameBuffer_set_brightness_proto,
+    .set_brightness = is31fl3741_framebuffer_set_brightness_proto,
-    .get_brightness = is31fl3741_FrameBuffer_get_brightness_proto,
+    .get_brightness = is31fl3741_framebuffer_get_brightness_proto,
-    .get_width = is31fl3741_FrameBuffer_get_width_proto,
+    .get_width = is31fl3741_framebuffer_get_width_proto,
-    .get_height = is31fl3741_FrameBuffer_get_height_proto,
+    .get_height = is31fl3741_framebuffer_get_height_proto,
-    .get_color_depth = is31fl3741_FrameBuffer_get_color_depth_proto,
+    .get_color_depth = is31fl3741_framebuffer_get_color_depth_proto,
-    .get_bytes_per_cell = is31fl3741_FrameBuffer_get_bytes_per_cell_proto,
+    .get_bytes_per_cell = is31fl3741_framebuffer_get_bytes_per_cell_proto,
-    .get_native_frames_per_second = is31fl3741_FrameBuffer_get_native_frames_per_second_proto,
+    .get_native_frames_per_second = is31fl3741_framebuffer_get_native_frames_per_second_proto,
-    .swapbuffers = is31fl3741_FrameBuffer_swapbuffers,
+    .swapbuffers = is31fl3741_framebuffer_swapbuffers,
-    .deinit = is31fl3741_FrameBuffer_deinit_proto,
+    .deinit = is31fl3741_framebuffer_deinit_proto,
 };
 
-STATIC mp_int_t is31fl3741_FrameBuffer_get_buffer(mp_obj_t self_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
+STATIC mp_int_t is31fl3741_framebuffer_get_buffer(mp_obj_t self_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
-    is31fl3741_FrameBuffer_obj_t *self = (is31fl3741_FrameBuffer_obj_t *)self_in;
+    is31fl3741_framebuffer_obj_t *self = (is31fl3741_framebuffer_obj_t *)self_in;
     // a readonly framebuffer would be unusual but not impossible
     if ((flags & MP_BUFFER_WRITE) && !(self->bufinfo.typecode & MP_OBJ_ARRAY_TYPECODE_FLAG_RW)) {
         return 1;
@@ -293,11 +293,11 @@ STATIC mp_int_t is31fl3741_FrameBuffer_get_buffer(mp_obj_t self_in, mp_buffer_in
 }
 
 MP_DEFINE_CONST_OBJ_TYPE(
-    is31fl3741_FrameBuffer_type,
+    is31fl3741_framebuffer_type,
     MP_QSTR_is31fl3741,
     MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
-    locals_dict, &is31fl3741_FrameBuffer_locals_dict,
+    locals_dict, &is31fl3741_framebuffer_locals_dict,
-    make_new, is31fl3741_FrameBuffer_make_new,
+    make_new, is31fl3741_framebuffer_make_new,
-    buffer, is31fl3741_FrameBuffer_get_buffer,
+    buffer, is31fl3741_framebuffer_get_buffer,
-    protocol, &is31fl3741_FrameBuffer_proto
+    protocol, &is31fl3741_framebuffer_proto
     );

shared-bindings/is31fl3741/FrameBuffer.h

@@ -29,22 +29,22 @@
 #include "shared-module/is31fl3741/FrameBuffer.h"
 #include "shared-module/is31fl3741/IS31FL3741.h"
 
-extern const mp_obj_type_t is31fl3741_FrameBuffer_type;
+extern const mp_obj_type_t is31fl3741_framebuffer_type;
 
-void common_hal_is31fl3741_FrameBuffer_construct(is31fl3741_FrameBuffer_obj_t *self, int width, int height, mp_obj_t framebuffer, is31fl3741_IS31FL3741_obj_t *is31, mp_obj_t mapping);
+void common_hal_is31fl3741_framebuffer_construct(is31fl3741_framebuffer_obj_t *self, int width, int height, mp_obj_t framebuffer, is31fl3741_IS31FL3741_obj_t *is31, mp_obj_t mapping);
 
-void common_hal_is31fl3741_FrameBuffer_deinit(is31fl3741_FrameBuffer_obj_t *);
+void common_hal_is31fl3741_framebuffer_deinit(is31fl3741_framebuffer_obj_t *);
 
-int common_hal_is31fl3741_FrameBuffer_get_width(is31fl3741_FrameBuffer_obj_t *self);
+int common_hal_is31fl3741_framebuffer_get_width(is31fl3741_framebuffer_obj_t *self);
-int common_hal_is31fl3741_FrameBuffer_get_height(is31fl3741_FrameBuffer_obj_t *self);
+int common_hal_is31fl3741_framebuffer_get_height(is31fl3741_framebuffer_obj_t *self);
 
-void common_hal_is31fl3741_FrameBuffer_set_global_current(is31fl3741_FrameBuffer_obj_t *self, uint8_t current);
+void common_hal_is31fl3741_framebuffer_set_global_current(is31fl3741_framebuffer_obj_t *self, uint8_t current);
-uint8_t common_hal_is31fl3741_FrameBuffer_get_global_current(is31fl3741_FrameBuffer_obj_t *self);
+uint8_t common_hal_is31fl3741_framebuffer_get_global_current(is31fl3741_framebuffer_obj_t *self);
 
-void common_hal_is31fl3741_FrameBuffer_set_paused(is31fl3741_FrameBuffer_obj_t *self, bool paused);
+void common_hal_is31fl3741_framebuffer_set_paused(is31fl3741_framebuffer_obj_t *self, bool paused);
-bool common_hal_is31fl3741_FrameBuffer_get_paused(is31fl3741_FrameBuffer_obj_t *self);
+bool common_hal_is31fl3741_framebuffer_get_paused(is31fl3741_framebuffer_obj_t *self);
-void common_hal_is31fl3741_FrameBuffer_refresh(is31fl3741_FrameBuffer_obj_t *self, uint8_t *dirtyrows);
+void common_hal_is31fl3741_framebuffer_refresh(is31fl3741_framebuffer_obj_t *self, uint8_t *dirtyrows);
 
-void common_hal_is31fl3741_FrameBuffer_reconstruct(is31fl3741_FrameBuffer_obj_t *self, mp_obj_t framebuffer);
+void common_hal_is31fl3741_framebuffer_reconstruct(is31fl3741_framebuffer_obj_t *self, mp_obj_t framebuffer);
 
-void is31fl3741_FrameBuffer_collect_ptrs(is31fl3741_FrameBuffer_obj_t *self);
+void is31fl3741_framebuffer_collect_ptrs(is31fl3741_framebuffer_obj_t *self);

shared-bindings/is31fl3741/__init__.c

@@ -37,7 +37,7 @@
 STATIC const mp_rom_map_elem_t is31fl3741_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_is31fl3741) },
     { MP_ROM_QSTR(MP_QSTR_IS31FL3741), MP_ROM_PTR(&is31fl3741_IS31FL3741_type) },
-    { MP_ROM_QSTR(MP_QSTR_IS31FL3741_FrameBuffer), MP_ROM_PTR(&is31fl3741_FrameBuffer_type) },
+    { MP_ROM_QSTR(MP_QSTR_IS31FL3741_FrameBuffer), MP_ROM_PTR(&is31fl3741_framebuffer_type) },
 };
 
 STATIC MP_DEFINE_CONST_DICT(is31fl3741_module_globals, is31fl3741_module_globals_table);

shared-bindings/paralleldisplaybus/ParallelBus.h

@@ -53,3 +53,7 @@ void common_hal_paralleldisplaybus_parallelbus_send(mp_obj_t self, display_byte_
     display_chip_select_behavior_t chip_select, const uint8_t *data, uint32_t data_length);
 
 void common_hal_paralleldisplaybus_parallelbus_end_transaction(mp_obj_t self);
+
+// The ParallelBus object always lives off the MP heap. So, code must collect any pointers
+// back to the MP heap manually. Otherwise they'll get freed.
+void common_hal_paralleldisplaybus_parallelbus_collect_ptrs(mp_obj_t self);

shared-bindings/supervisor/Runtime.c

@@ -186,32 +186,6 @@ MP_PROPERTY_GETSET(supervisor_runtime_ble_workflow_obj,
     (mp_obj_t)&supervisor_runtime_get_ble_workflow_obj,
     (mp_obj_t)&supervisor_runtime_set_ble_workflow_obj);
 
-//|     next_stack_limit: int
-//|     """The size of the stack for the next vm run. If its too large, the default will be used.
-//|
-//|     **Limitations**: Stack size is fixed at startup on the ``espressif`` port; setting this will have no effect.
-//|     """
-STATIC mp_obj_t supervisor_runtime_get_next_stack_limit(mp_obj_t self) {
-    return mp_obj_new_int(get_next_stack_size());
-}
-MP_DEFINE_CONST_FUN_OBJ_1(supervisor_runtime_get_next_stack_limit_obj, supervisor_runtime_get_next_stack_limit);
-
-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);
-    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);
-
-MP_PROPERTY_GETSET(supervisor_runtime_next_stack_limit_obj,
-    (mp_obj_t)&supervisor_runtime_get_next_stack_limit_obj,
-    (mp_obj_t)&supervisor_runtime_set_next_stack_limit_obj);
-
 //|     rgb_status_brightness: int
 //|     """Set brightness of status RGB LED from 0-255. This will take effect
 //|     after the current code finishes and the status LED is used to show
@@ -245,7 +219,6 @@ STATIC const mp_rom_map_elem_t supervisor_runtime_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_safe_mode_reason), MP_ROM_PTR(&supervisor_runtime_safe_mode_reason_obj) },
     { MP_ROM_QSTR(MP_QSTR_autoreload), MP_ROM_PTR(&supervisor_runtime_autoreload_obj) },
     { MP_ROM_QSTR(MP_QSTR_ble_workflow),  MP_ROM_PTR(&supervisor_runtime_ble_workflow_obj) },
-    { MP_ROM_QSTR(MP_QSTR_next_stack_limit),  MP_ROM_PTR(&supervisor_runtime_next_stack_limit_obj) },
     { MP_ROM_QSTR(MP_QSTR_rgb_status_brightness),  MP_ROM_PTR(&supervisor_runtime_rgb_status_brightness_obj) },
 };
 

shared-bindings/supervisor/__init__.c

@@ -30,6 +30,7 @@
 #include "py/objstr.h"
 
 #include "shared/runtime/interrupt_char.h"
+#include "supervisor/port.h"
 #include "supervisor/shared/display.h"
 #include "supervisor/shared/reload.h"
 #include "supervisor/shared/traceback.h"
@@ -153,18 +154,18 @@ STATIC mp_obj_t supervisor_set_next_code_file(size_t n_args, const mp_obj_t *pos
     }
     size_t len;
     const char *filename = mp_obj_str_get_data(args.filename.u_obj, &len);
-    free_memory(next_code_allocation);
+    if (next_code_configuration != NULL) {
+        port_free(next_code_configuration);
+        next_code_configuration = NULL;
+    }
     if (options != 0 || len != 0) {
-        next_code_allocation = allocate_memory(align32_size(sizeof(next_code_info_t) + len + 1), false, true);
+        next_code_configuration = port_malloc(sizeof(supervisor_next_code_info_t) + len + 1, false);
-        if (next_code_allocation == NULL) {
+        if (next_code_configuration == NULL) {
-            m_malloc_fail(sizeof(next_code_info_t) + len + 1);
+            m_malloc_fail(sizeof(supervisor_next_code_info_t) + len + 1);
         }
-        next_code_info_t *next_code = (next_code_info_t *)next_code_allocation->ptr;
+        next_code_configuration->options = options | SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
-        next_code->options = options | SUPERVISOR_NEXT_CODE_OPT_NEWLY_SET;
+        memcpy(&next_code_configuration->filename, filename, len);
-        memcpy(&next_code->filename, filename, len);
+        next_code_configuration->filename[len] = '\0';
-        next_code->filename[len] = '\0';
-    } else {
-        next_code_allocation = NULL;
     }
     return mp_const_none;
 }
@@ -229,14 +230,14 @@ MP_DEFINE_CONST_FUN_OBJ_0(supervisor_ticks_ms_obj, supervisor_ticks_ms);
 //|     ...
 //|
 STATIC mp_obj_t supervisor_get_previous_traceback(void) {
-    if (prev_traceback_allocation) {
+    if (prev_traceback_string) {
-        size_t len = strlen((const char *)prev_traceback_allocation->ptr);
+        size_t len = strlen(prev_traceback_string);
         if (len > 0) {
             mp_obj_str_t *o = mp_obj_malloc(mp_obj_str_t, &mp_type_str);
             o->len = len;
             // callers probably aren't going to compare this string, so skip computing the hash
             o->hash = 0;
-            o->data = (const byte *)prev_traceback_allocation->ptr;
+            o->data = (const byte *)prev_traceback_string;
             return MP_OBJ_FROM_PTR(o);
         }
     }
@@ -292,34 +293,33 @@ STATIC mp_obj_t supervisor_set_usb_identification(size_t n_args, const mp_obj_t
     } args;
     mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, (mp_arg_val_t *)&args);
 
-    if (!usb_identification_allocation) {
+    if (custom_usb_identification == NULL) {
-        usb_identification_allocation = allocate_memory(sizeof(usb_identification_t), false, true);
+        custom_usb_identification = port_malloc(sizeof(usb_identification_t), false);
     }
-    usb_identification_t *identification = (usb_identification_t *)usb_identification_allocation->ptr;
 
     mp_arg_validate_int_range(args.vid.u_int, -1, (1 << 16) - 1, MP_QSTR_vid);
     mp_arg_validate_int_range(args.pid.u_int, -1, (1 << 16) - 1, MP_QSTR_pid);
 
-    identification->vid = args.vid.u_int > -1 ? args.vid.u_int : USB_VID;
+    custom_usb_identification->vid = args.vid.u_int > -1 ? args.vid.u_int : USB_VID;
-    identification->pid = args.pid.u_int > -1 ? args.pid.u_int : USB_PID;
+    custom_usb_identification->pid = args.pid.u_int > -1 ? args.pid.u_int : USB_PID;
 
     mp_buffer_info_t info;
     if (args.manufacturer.u_obj != mp_const_none) {
         mp_get_buffer_raise(args.manufacturer.u_obj, &info, MP_BUFFER_READ);
         mp_arg_validate_length_range(info.len, 0, 126, MP_QSTR_manufacturer);
-        memcpy(identification->manufacturer_name, info.buf, info.len);
+        memcpy(custom_usb_identification->manufacturer_name, info.buf, info.len);
-        identification->manufacturer_name[info.len] = 0;
+        custom_usb_identification->manufacturer_name[info.len] = 0;
     } else {
-        strcpy(identification->manufacturer_name, USB_MANUFACTURER);
+        strcpy(custom_usb_identification->manufacturer_name, USB_MANUFACTURER);
     }
 
     if (args.product.u_obj != mp_const_none) {
         mp_get_buffer_raise(args.product.u_obj, &info, MP_BUFFER_READ);
         mp_arg_validate_length_range(info.len, 0, 126, MP_QSTR_product);
-        memcpy(identification->product_name, info.buf, info.len);
+        memcpy(custom_usb_identification->product_name, info.buf, info.len);
-        identification->product_name[info.len] = 0;
+        custom_usb_identification->product_name[info.len] = 0;
     } else {
-        strcpy(identification->product_name, USB_PRODUCT);
+        strcpy(custom_usb_identification->product_name, USB_PRODUCT);
     }
 
     return mp_const_none;

shared-bindings/supervisor/__init__.h

@@ -32,10 +32,20 @@
 
 #include "common-hal/supervisor/Runtime.h"
 #include "shared-module/supervisor/StatusBar.h"
+#include "supervisor/usb.h"
+
+typedef struct {
+    uint8_t options;
+    char filename[];
+} supervisor_next_code_info_t;
 
 extern const super_runtime_obj_t common_hal_supervisor_runtime_obj;
 extern supervisor_status_bar_obj_t shared_module_supervisor_status_bar_obj;
 extern mp_obj_t supervisor_ticks_ms(void);
 
+extern char *prev_traceback_string;
+
+extern supervisor_next_code_info_t *next_code_configuration;
+extern usb_identification_t *custom_usb_identification;
 
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_SUPERVISOR___INIT___H

shared-module/busdisplay/BusDisplay.c

@@ -441,4 +441,5 @@ void reset_busdisplay(busdisplay_busdisplay_obj_t *self) {
 
 void busdisplay_busdisplay_collect_ptrs(busdisplay_busdisplay_obj_t *self) {
     displayio_display_core_collect_ptrs(&self->core);
+    displayio_display_bus_collect_ptrs(&self->bus);
 }

shared-module/displayio/__init__.c

@@ -37,7 +37,6 @@
 #include "shared-module/displayio/area.h"
 #include "supervisor/shared/display.h"
 #include "supervisor/shared/reload.h"
-#include "supervisor/memory.h"
 
 #include "supervisor/spi_flash_api.h"
 #include "py/mpconfig.h"
@@ -166,8 +165,8 @@ void common_hal_displayio_release_displays(void) {
             common_hal_rgbmatrix_rgbmatrix_deinit(&display_buses[i].rgbmatrix);
         #endif
         #if CIRCUITPY_IS31FL3741
-        } else if (bus_type == &is31fl3741_FrameBuffer_type) {
+        } else if (bus_type == &is31fl3741_framebuffer_type) {
-            common_hal_is31fl3741_FrameBuffer_deinit(&display_buses[i].is31fl3741);
+            common_hal_is31fl3741_framebuffer_deinit(&display_buses[i].is31fl3741);
         #endif
         #if CIRCUITPY_SHARPDISPLAY
         } else if (bus_type == &sharpdisplay_framebuffer_type) {
@@ -260,8 +259,8 @@ void reset_displays(void) {
             }
         #endif
         #if CIRCUITPY_IS31FL3741
-        } else if (display_bus_type == &is31fl3741_FrameBuffer_type) {
+        } else if (display_bus_type == &is31fl3741_framebuffer_type) {
-            is31fl3741_FrameBuffer_obj_t *is31fb = &display_buses[i].is31fl3741;
+            is31fl3741_framebuffer_obj_t *is31fb = &display_buses[i].is31fl3741;
 
             if (((uint32_t)is31fb->is31fl3741->i2c) < ((uint32_t)&display_buses) ||
                 ((uint32_t)is31fb->is31fl3741->i2c) > ((uint32_t)&display_buses + CIRCUITPY_DISPLAY_LIMIT)) {
@@ -284,9 +283,9 @@ void reset_displays(void) {
             }
 
             if (!any_display_uses_this_framebuffer(&is31fb->base)) {
-                common_hal_is31fl3741_FrameBuffer_deinit(is31fb);
+                common_hal_is31fl3741_framebuffer_deinit(is31fb);
             } else {
-                common_hal_is31fl3741_FrameBuffer_set_paused(is31fb, true);
+                common_hal_is31fl3741_framebuffer_set_paused(is31fb, true);
             }
         #endif
         #if CIRCUITPY_SHARPDISPLAY
@@ -351,8 +350,8 @@ void displayio_gc_collect(void) {
         }
         #endif
         #if CIRCUITPY_IS31FL3741
-        if (display_bus_type == &is31fl3741_FrameBuffer_type) {
+        if (display_bus_type == &is31fl3741_framebuffer_type) {
-            is31fl3741_FrameBuffer_collect_ptrs(&display_buses[i].is31fl3741);
+            is31fl3741_framebuffer_collect_ptrs(&display_buses[i].is31fl3741);
         }
         #endif
         #if CIRCUITPY_SHARPDISPLAY

shared-module/displayio/__init__.h

@@ -81,7 +81,7 @@ typedef struct {
         rgbmatrix_rgbmatrix_obj_t rgbmatrix;
         #endif
         #if CIRCUITPY_IS31FL3741
-        is31fl3741_FrameBuffer_obj_t is31fl3741;
+        is31fl3741_framebuffer_obj_t is31fl3741;
         #endif
         #if CIRCUITPY_SHARPDISPLAY
         sharpdisplay_framebuffer_obj_t sharpdisplay;

shared-module/displayio/bus_core.c

@@ -76,6 +76,7 @@ void displayio_display_bus_construct(displayio_display_bus_t *self,
         self->begin_transaction = common_hal_paralleldisplaybus_parallelbus_begin_transaction;
         self->send = common_hal_paralleldisplaybus_parallelbus_send;
         self->end_transaction = common_hal_paralleldisplaybus_parallelbus_end_transaction;
+        self->collect_ptrs = common_hal_paralleldisplaybus_parallelbus_collect_ptrs;
     } else
     #endif
     #if CIRCUITPY_FOURWIRE
@@ -85,6 +86,7 @@ void displayio_display_bus_construct(displayio_display_bus_t *self,
         self->begin_transaction = common_hal_fourwire_fourwire_begin_transaction;
         self->send = common_hal_fourwire_fourwire_send;
         self->end_transaction = common_hal_fourwire_fourwire_end_transaction;
+        self->collect_ptrs = common_hal_fourwire_fourwire_collect_ptrs;
     } else
     #endif
     #if CIRCUITPY_I2CDISPLAYBUS
@@ -94,6 +96,7 @@ void displayio_display_bus_construct(displayio_display_bus_t *self,
         self->begin_transaction = common_hal_i2cdisplaybus_i2cdisplaybus_begin_transaction;
         self->send = common_hal_i2cdisplaybus_i2cdisplaybus_send;
         self->end_transaction = common_hal_i2cdisplaybus_i2cdisplaybus_end_transaction;
+        self->collect_ptrs = common_hal_i2cdisplaybus_i2cdisplaybus_collect_ptrs;
     } else
     #endif
     {
@@ -231,3 +234,7 @@ void displayio_display_bus_set_region_to_update(displayio_display_bus_t *self, d
         displayio_display_bus_end_transaction(self);
     }
 }
+
+void displayio_display_bus_collect_ptrs(displayio_display_bus_t *self) {
+    self->collect_ptrs(self->bus);
+}

shared-module/displayio/bus_core.h

@@ -41,6 +41,7 @@ typedef struct {
     display_bus_begin_transaction begin_transaction;
     display_bus_send send;
     display_bus_end_transaction end_transaction;
+    display_bus_collect_ptrs collect_ptrs;
     uint16_t ram_width;
     uint16_t ram_height;
     int16_t colstart;

shared-module/epaperdisplay/EPaperDisplay.c

@@ -504,6 +504,7 @@ void epaperdisplay_epaperdisplay_reset(epaperdisplay_epaperdisplay_obj_t *self)
 
 void epaperdisplay_epaperdisplay_collect_ptrs(epaperdisplay_epaperdisplay_obj_t *self) {
     displayio_display_core_collect_ptrs(&self->core);
+    displayio_display_bus_collect_ptrs(&self->bus);
     gc_collect_ptr((void *)self->start_sequence);
     gc_collect_ptr((void *)self->stop_sequence);
 }

shared-module/fourwire/FourWire.c

@@ -42,9 +42,6 @@ void common_hal_fourwire_fourwire_construct(fourwire_fourwire_obj_t *self,
 
     self->bus = spi;
     common_hal_busio_spi_never_reset(self->bus);
-    // Our object is statically allocated off the heap so make sure the bus object lives to the end
-    // of the heap as well.
-    gc_never_free(self->bus);
 
     self->frequency = baudrate;
     self->polarity = polarity;
@@ -176,3 +173,8 @@ void common_hal_fourwire_fourwire_end_transaction(mp_obj_t obj) {
     common_hal_digitalio_digitalinout_set_value(&self->chip_select, true);
     common_hal_busio_spi_unlock(self->bus);
 }
+
+void common_hal_fourwire_fourwire_collect_ptrs(mp_obj_t obj) {
+    fourwire_fourwire_obj_t *self = MP_OBJ_TO_PTR(obj);
+    gc_collect_ptr((void *)self->bus);
+}

shared-module/i2cdisplaybus/I2CDisplayBus.c

@@ -61,9 +61,6 @@ void common_hal_i2cdisplaybus_i2cdisplaybus_construct(i2cdisplaybus_i2cdisplaybu
     // Write to the device and return 0 on success or an appropriate error code from mperrno.h
     self->bus = i2c;
     common_hal_busio_i2c_never_reset(self->bus);
-    // Our object is statically allocated off the heap so make sure the bus object lives to the end
-    // of the heap as well.
-    gc_never_free(self->bus);
 
     self->address = device_address;
 }
@@ -72,6 +69,10 @@ void common_hal_i2cdisplaybus_i2cdisplaybus_deinit(i2cdisplaybus_i2cdisplaybus_o
     if (self->bus == &self->inline_bus) {
         common_hal_busio_i2c_deinit(self->bus);
     }
+    // TODO figure out how to undo never_reset. maybe only mark never_reset when
+    // we subsume objects off the mp heap.
+
+    self->bus = NULL;
 
     if (self->reset.base.type == &digitalio_digitalinout_type) {
         common_hal_digitalio_digitalinout_deinit(&self->reset);
@@ -126,3 +127,8 @@ void common_hal_i2cdisplaybus_i2cdisplaybus_end_transaction(mp_obj_t obj) {
     i2cdisplaybus_i2cdisplaybus_obj_t *self = MP_OBJ_TO_PTR(obj);
     common_hal_busio_i2c_unlock(self->bus);
 }
+
+void common_hal_i2cdisplaybus_i2cdisplaybus_collect_ptrs(mp_obj_t obj) {
+    i2cdisplaybus_i2cdisplaybus_obj_t *self = MP_OBJ_TO_PTR(obj);
+    gc_collect_ptr((void *)self->bus);
+}

shared-module/is31fl3741/FrameBuffer.c

@@ -32,14 +32,14 @@
 #include "py/objproperty.h"
 #include "py/runtime.h"
 
-#include "shared-module/is31fl3741/allocator.h"
 #include "shared-bindings/is31fl3741/IS31FL3741.h"
 #include "shared-bindings/is31fl3741/FrameBuffer.h"
 #include "shared-bindings/util.h"
 #include "shared-module/framebufferio/FramebufferDisplay.h"
 #include "shared-bindings/busio/I2C.h"
+#include "supervisor/port.h"
 
-void common_hal_is31fl3741_FrameBuffer_construct(is31fl3741_FrameBuffer_obj_t *self, int width, int height, mp_obj_t framebuffer, is31fl3741_IS31FL3741_obj_t *is31, mp_obj_t mapping) {
+void common_hal_is31fl3741_framebuffer_construct(is31fl3741_framebuffer_obj_t *self, int width, int height, mp_obj_t framebuffer, is31fl3741_IS31FL3741_obj_t *is31, mp_obj_t mapping) {
     self->width = width;
     self->height = height;
 
@@ -48,10 +48,6 @@ void common_hal_is31fl3741_FrameBuffer_construct(is31fl3741_FrameBuffer_obj_t *s
     self->is31fl3741 = is31;
 
     common_hal_busio_i2c_never_reset(self->is31fl3741->i2c);
-    // Our object is statically allocated off the heap so make sure the bus object lives to the end
-    // of the heap as well.
-    gc_never_free(self->is31fl3741->i2c);
-    gc_never_free(self->is31fl3741);
 
     mp_obj_t *items;
     size_t len;
@@ -61,7 +57,10 @@ void common_hal_is31fl3741_FrameBuffer_construct(is31fl3741_FrameBuffer_obj_t *s
         mp_raise_ValueError(MP_ERROR_TEXT("LED mappings must match display size"));
     }
 
-    self->mapping = common_hal_is31fl3741_allocator_impl(sizeof(uint16_t) * len);
+    self->mapping = port_malloc(sizeof(uint16_t) * len, false);
+    if (self->mapping == NULL) {
+        m_malloc_fail(sizeof(uint16_t) * len);
+    }
     for (size_t i = 0; i < len; i++) {
         mp_int_t value = mp_obj_get_int(items[i]);
         // We only store up to 16 bits
@@ -71,10 +70,10 @@ void common_hal_is31fl3741_FrameBuffer_construct(is31fl3741_FrameBuffer_obj_t *s
         self->mapping[i] = (uint16_t)value;
     }
 
-    common_hal_is31fl3741_FrameBuffer_reconstruct(self, framebuffer);
+    common_hal_is31fl3741_framebuffer_reconstruct(self, framebuffer);
 }
 
-void common_hal_is31fl3741_FrameBuffer_reconstruct(is31fl3741_FrameBuffer_obj_t *self, mp_obj_t framebuffer) {
+void common_hal_is31fl3741_framebuffer_reconstruct(is31fl3741_framebuffer_obj_t *self, mp_obj_t framebuffer) {
     self->paused = 1;
 
     if (framebuffer) {
@@ -89,10 +88,15 @@ void common_hal_is31fl3741_FrameBuffer_reconstruct(is31fl3741_FrameBuffer_obj_t
         // verify that the matrix is big enough
         mp_get_index(mp_obj_get_type(self->framebuffer), self->bufinfo.len, MP_OBJ_NEW_SMALL_INT(self->bufsize - 1), false);
     } else {
-        common_hal_is31fl3741_free_impl(self->bufinfo.buf);
+        if (self->framebuffer == NULL && self->bufinfo.buf != NULL) {
+            port_free(self->bufinfo.buf);
+        }
 
         self->framebuffer = NULL;
-        self->bufinfo.buf = common_hal_is31fl3741_allocator_impl(self->bufsize);
+        self->bufinfo.buf = port_malloc(self->bufsize, false);
+        if (self->bufinfo.buf == NULL) {
+            return;
+        }
         self->bufinfo.len = self->bufsize;
         self->bufinfo.typecode = 'H' | MP_OBJ_ARRAY_TYPECODE_FLAG_RW;
     }
@@ -112,14 +116,18 @@ void common_hal_is31fl3741_FrameBuffer_reconstruct(is31fl3741_FrameBuffer_obj_t
     self->paused = 0;
 }
 
-void common_hal_is31fl3741_FrameBuffer_deinit(is31fl3741_FrameBuffer_obj_t *self) {
+void common_hal_is31fl3741_framebuffer_deinit(is31fl3741_framebuffer_obj_t *self) {
     common_hal_is31fl3741_end_transaction(self->is31fl3741); // in case we still had a lock
 
     common_hal_is31fl3741_IS31FL3741_deinit(self->is31fl3741);
 
-    if (self->mapping != 0) {
+    if (self->mapping != NULL) {
-        common_hal_is31fl3741_free_impl(self->mapping);
+        port_free(self->mapping);
-        self->mapping = 0;
+        self->mapping = NULL;
+    }
+
+    if (self->framebuffer == NULL && self->bufinfo.buf != NULL) {
+        port_free(self->bufinfo.buf);
     }
 
     self->base.type = NULL;
@@ -129,15 +137,15 @@ void common_hal_is31fl3741_FrameBuffer_deinit(is31fl3741_FrameBuffer_obj_t *self
     self->framebuffer = NULL;
 }
 
-void common_hal_is31fl3741_FrameBuffer_set_paused(is31fl3741_FrameBuffer_obj_t *self, bool paused) {
+void common_hal_is31fl3741_framebuffer_set_paused(is31fl3741_framebuffer_obj_t *self, bool paused) {
     self->paused = paused;
 }
 
-bool common_hal_is31fl3741_FrameBuffer_get_paused(is31fl3741_FrameBuffer_obj_t *self) {
+bool common_hal_is31fl3741_framebuffer_get_paused(is31fl3741_framebuffer_obj_t *self) {
     return self->paused;
 }
 
-void common_hal_is31fl3741_FrameBuffer_refresh(is31fl3741_FrameBuffer_obj_t *self, uint8_t *dirtyrows) {
+void common_hal_is31fl3741_framebuffer_refresh(is31fl3741_framebuffer_obj_t *self, uint8_t *dirtyrows) {
     if (!self->paused) {
         common_hal_is31fl3741_begin_transaction(self->is31fl3741);
 
@@ -205,24 +213,16 @@ void common_hal_is31fl3741_FrameBuffer_refresh(is31fl3741_FrameBuffer_obj_t *sel
     }
 }
 
-int common_hal_is31fl3741_FrameBuffer_get_width(is31fl3741_FrameBuffer_obj_t *self) {
+int common_hal_is31fl3741_framebuffer_get_width(is31fl3741_framebuffer_obj_t *self) {
     return self->width;
 }
 
-int common_hal_is31fl3741_FrameBuffer_get_height(is31fl3741_FrameBuffer_obj_t *self) {
+int common_hal_is31fl3741_framebuffer_get_height(is31fl3741_framebuffer_obj_t *self) {
     return self->height;
 }
 
-void *common_hal_is31fl3741_allocator_impl(size_t sz) {
+void is31fl3741_framebuffer_collect_ptrs(is31fl3741_framebuffer_obj_t *self) {
-    supervisor_allocation *allocation = allocate_memory(align32_size(sz), false, true);
-    return allocation ? allocation->ptr : NULL;
-}
-
-void common_hal_is31fl3741_free_impl(void *ptr_in) {
-    free_memory(allocation_from_ptr(ptr_in));
-}
-
-void is31fl3741_FrameBuffer_collect_ptrs(is31fl3741_FrameBuffer_obj_t *self) {
     gc_collect_ptr(self->framebuffer);
-    gc_collect_ptr(self->mapping);
+    gc_collect_ptr(self->is31fl3741->i2c);
+    gc_collect_ptr(self->is31fl3741);
 }

shared-module/is31fl3741/FrameBuffer.h

@@ -30,7 +30,7 @@
 #include "lib/protomatter/src/core.h"
 #include "shared-module/is31fl3741/IS31FL3741.h"
 
-extern const mp_obj_type_t is31fl3741_FrameBuffer_type;
+extern const mp_obj_type_t is31fl3741_framebuffer_type;
 typedef struct {
     mp_obj_base_t base;
     is31fl3741_IS31FL3741_obj_t *is31fl3741;
@@ -43,4 +43,4 @@ typedef struct {
     bool paused;
     bool scale;
     bool auto_gamma;
-} is31fl3741_FrameBuffer_obj_t;
+} is31fl3741_framebuffer_obj_t;

shared-module/os/getenv.c

@@ -42,7 +42,6 @@
 #include "py/parsenum.h"
 #include "py/runtime.h"
 #include "supervisor/filesystem.h"
-#include "supervisor/memory.h"
 
 #define GETENV_PATH "/settings.toml"
 

shared-module/paralleldisplaybus/ParallelBus.c

@@ -29,9 +29,12 @@
 
 // If non-sequential pins aren't supported, then this default (weak)
 // implementation will raise an exception for you.
-__attribute__((weak))
+MP_WEAK void common_hal_paralleldisplaybus_parallelbus_construct_nonsequential(paralleldisplaybus_parallelbus_obj_t *self,
-void common_hal_paralleldisplaybus_parallelbus_construct_nonsequential(paralleldisplaybus_parallelbus_obj_t *self,
     uint8_t n_pins, const mcu_pin_obj_t **data_pins, const mcu_pin_obj_t *command, const mcu_pin_obj_t *chip_select,
     const mcu_pin_obj_t *write, const mcu_pin_obj_t *read, const mcu_pin_obj_t *reset, uint32_t frequency) {
     mp_raise_NotImplementedError(MP_ERROR_TEXT("This microcontroller only supports data0=, not data_pins=, because it requires contiguous pins."));
 }
+
+MP_WEAK void common_hal_paralleldisplaybus_parallelbus_collect_ptrs(mp_obj_t self) {
+
+}

shared-module/rgbmatrix/RGBMatrix.c

@@ -79,12 +79,11 @@ STATIC void common_hal_rgbmatrix_rgbmatrix_construct1(rgbmatrix_rgbmatrix_obj_t
         }
         // verify that the matrix is big enough
         mp_get_index(mp_obj_get_type(self->framebuffer), self->bufinfo.len, MP_OBJ_NEW_SMALL_INT(self->bufsize - 1), false);
-        self->allocation = NULL;
     } else {
-        // The supervisor allocation can move memory by changing self->allocation->ptr.
+        self->bufinfo.buf = port_malloc(self->bufsize, false);
-        // So we hold onto it and update bufinfo every time we use it.
+        if (self->bufinfo.buf == NULL) {
-        self->allocation = allocate_memory(align32_size(self->bufsize), false, true);
+            m_malloc_fail(self->bufsize);
-        self->bufinfo.buf = self->allocation->ptr;
+        }
         self->bufinfo.len = self->bufsize;
         self->bufinfo.typecode = 'H' | MP_OBJ_ARRAY_TYPECODE_FLAG_RW;
     }
@@ -150,9 +149,7 @@ STATIC void free_pin_seq(uint8_t *seq, int count) {
 
 extern int pm_row_count;
 STATIC void common_hal_rgbmatrix_rgbmatrix_deinit1(rgbmatrix_rgbmatrix_obj_t *self) {
-    if (self->timer != NULL) {
+    common_hal_rgbmatrix_timer_disable(self->timer);
-        common_hal_rgbmatrix_timer_disable(self->timer);
-    }
 
     if (_PM_protoPtr == &self->protomatter) {
         _PM_protoPtr = NULL;
@@ -166,15 +163,14 @@ STATIC void common_hal_rgbmatrix_rgbmatrix_deinit1(rgbmatrix_rgbmatrix_obj_t *se
 
     // If it was supervisor-allocated, it is supervisor-freed and the pointer
     // is zeroed, otherwise the pointer is just zeroed
-    if (self->allocation != NULL) {
+    if (self->framebuffer == mp_const_none) {
-        free_memory(self->allocation);
+        port_free(self->bufinfo.buf);
     }
+    self->bufinfo.buf = NULL;
 
     // If a framebuffer was passed in to the constructor, clear the reference
     // here so that it will become GC'able
     self->framebuffer = mp_const_none;
-
-    self->bufinfo.buf = NULL;
 }
 
 void common_hal_rgbmatrix_rgbmatrix_deinit(rgbmatrix_rgbmatrix_obj_t *self) {
@@ -194,21 +190,22 @@ void common_hal_rgbmatrix_rgbmatrix_deinit(rgbmatrix_rgbmatrix_obj_t *self) {
 }
 
 void common_hal_rgbmatrix_rgbmatrix_get_bufinfo(rgbmatrix_rgbmatrix_obj_t *self, mp_buffer_info_t *bufinfo) {
-    if (self->allocation != NULL) {
-        self->bufinfo.buf = self->allocation->ptr;
-    }
     *bufinfo = self->bufinfo;
 }
 
 void common_hal_rgbmatrix_rgbmatrix_reconstruct(rgbmatrix_rgbmatrix_obj_t *self) {
+    common_hal_rgbmatrix_rgbmatrix_set_paused(self, true);
+    // Stop using any Python provided framebuffer.
     if (self->framebuffer != mp_const_none) {
         memset(&self->bufinfo, 0, sizeof(self->bufinfo));
+        self->bufinfo.buf = port_malloc(self->bufsize, false);
+        if (self->bufinfo.buf == NULL) {
+            common_hal_rgbmatrix_rgbmatrix_deinit(self);
+            return;
+        }
+        self->bufinfo.len = self->bufsize;
+        self->bufinfo.typecode = 'H' | MP_OBJ_ARRAY_TYPECODE_FLAG_RW;
     }
-    #if CIRCUITPY_RGBMATRIX_USES_SUPERVISOR_ALLOCATION
-    common_hal_rgbmatrix_rgbmatrix_set_paused(self, true);
-    common_hal_rgbmatrix_rgbmatrix_deinit1(self);
-    common_hal_rgbmatrix_rgbmatrix_construct1(self, mp_const_none);
-    #endif
     memset(self->bufinfo.buf, 0, self->bufinfo.len);
     common_hal_rgbmatrix_rgbmatrix_set_paused(self, false);
 }
@@ -222,9 +219,6 @@ void common_hal_rgbmatrix_rgbmatrix_set_paused(rgbmatrix_rgbmatrix_obj_t *self,
         _PM_stop(&self->protomatter);
     } else if (!paused && self->paused) {
         _PM_resume(&self->protomatter);
-        if (self->allocation) {
-            self->bufinfo.buf = self->allocation->ptr;
-        }
         _PM_convert_565(&self->protomatter, self->bufinfo.buf, self->width);
         _PM_swapbuffer_maybe(&self->protomatter);
     }
@@ -237,9 +231,6 @@ bool common_hal_rgbmatrix_rgbmatrix_get_paused(rgbmatrix_rgbmatrix_obj_t *self)
 
 void common_hal_rgbmatrix_rgbmatrix_refresh(rgbmatrix_rgbmatrix_obj_t *self) {
     if (!self->paused) {
-        if (self->allocation != NULL) {
-            self->bufinfo.buf = self->allocation->ptr;
-        }
         _PM_convert_565(&self->protomatter, self->bufinfo.buf, self->width);
         _PM_swapbuffer_maybe(&self->protomatter);
     }
@@ -253,44 +244,3 @@ int common_hal_rgbmatrix_rgbmatrix_get_height(rgbmatrix_rgbmatrix_obj_t *self) {
     int computed_height = (self->rgb_count / 3) * (1 << (self->addr_count)) * self->tile;
     return computed_height;
 }
-
-// Track the returned pointers and their matching allocation so that we can free
-// them even when the memory was moved by the supervisor. This prevents leaks
-// but doesn't protect against the memory being used after its been freed! The
-// long term fix is to utilize a permanent heap that can be shared with MP's
-// split heap.
-typedef struct matrix_allocation {
-    void *original_pointer;
-    supervisor_allocation *allocation;
-} matrix_allocation_t;
-
-// Four should be more than we ever need. ProtoMatter does 3 allocations currently.
-static matrix_allocation_t allocations[4];
-
-void *common_hal_rgbmatrix_allocator_impl(size_t sz) {
-    supervisor_allocation *allocation = allocate_memory(align32_size(sz), false, true);
-    if (allocation == NULL) {
-        return NULL;
-    }
-    for (size_t i = 0; i < sizeof(allocations); i++) {
-        matrix_allocation_t *matrix_allocation = &allocations[i];
-        if (matrix_allocation->original_pointer == NULL) {
-            matrix_allocation->original_pointer = allocation->ptr;
-            matrix_allocation->allocation = allocation;
-            return allocation->ptr;
-        }
-    }
-    return NULL;
-}
-
-void common_hal_rgbmatrix_free_impl(void *ptr_in) {
-    for (size_t i = 0; i < sizeof(allocations); i++) {
-        matrix_allocation_t *matrix_allocation = &allocations[i];
-        if (matrix_allocation->original_pointer == ptr_in) {
-            matrix_allocation->original_pointer = NULL;
-            free_memory(matrix_allocation->allocation);
-            matrix_allocation->allocation = NULL;
-            return;
-        }
-    }
-}

shared-module/rgbmatrix/RGBMatrix.h

@@ -28,14 +28,12 @@
 
 #include "py/obj.h"
 #include "lib/protomatter/src/core.h"
-#include "supervisor/memory.h"
 
 extern const mp_obj_type_t rgbmatrix_RGBMatrix_type;
 typedef struct {
     mp_obj_base_t base;
     mp_obj_t framebuffer;
     mp_buffer_info_t bufinfo;
-    supervisor_allocation *allocation;
     Protomatter_core protomatter;
     void *timer;
     uint16_t bufsize, width;

shared-module/rgbmatrix/allocator.h

@@ -29,17 +29,13 @@
 #include <stdbool.h>
 #include "py/gc.h"
 #include "py/misc.h"
-#include "supervisor/memory.h"
+#include "supervisor/port.h"
 
 #if defined(CONFIG_IDF_TARGET_ESP32S3) || defined(CONFIG_IDF_TARGET_ESP32S2)
-// Use DMA-capable RAM (not PSRAM) for framebuffer:
 #include "components/heap/include/esp_heap_caps.h"
 #define _PM_allocate(x) heap_caps_malloc(x, MALLOC_CAP_DMA | MALLOC_CAP_8BIT)
 #define _PM_free(x) heap_caps_free(x)
 #else
-#define _PM_allocate common_hal_rgbmatrix_allocator_impl
+#define _PM_allocate(x) port_malloc(x, true)
-#define _PM_free(x) (common_hal_rgbmatrix_free_impl((x)), (x) = NULL, (void)0)
+#define _PM_free(x) port_free(x)
 #endif
-
-extern void *common_hal_rgbmatrix_allocator_impl(size_t sz);
-extern void common_hal_rgbmatrix_free_impl(void *);

shared-module/sharpdisplay/SharpMemoryFramebuffer.c

@@ -32,8 +32,7 @@
 #include "shared-bindings/microcontroller/Pin.h"
 #include "shared-bindings/sharpdisplay/SharpMemoryFramebuffer.h"
 #include "shared-module/sharpdisplay/SharpMemoryFramebuffer.h"
-
+#include "supervisor/port.h"
-#include "supervisor/memory.h"
 
 #define SHARPMEM_BIT_WRITECMD_LSB (0x80)
 #define JDI_BIT_WRITECMD_LSB      (0x90)
@@ -86,9 +85,6 @@ void common_hal_sharpdisplay_framebuffer_reset(sharpdisplay_framebuffer_obj_t *s
 }
 
 void common_hal_sharpdisplay_framebuffer_reconstruct(sharpdisplay_framebuffer_obj_t *self) {
-    // Look up the allocation by the old pointer and get the new pointer from it.
-    supervisor_allocation *alloc = allocation_from_ptr(self->bufinfo.buf);
-    self->bufinfo.buf = alloc ? alloc->ptr : NULL;
 }
 
 void common_hal_sharpdisplay_framebuffer_get_bufinfo(sharpdisplay_framebuffer_obj_t *self, mp_buffer_info_t *bufinfo) {
@@ -96,12 +92,11 @@ void common_hal_sharpdisplay_framebuffer_get_bufinfo(sharpdisplay_framebuffer_ob
         int row_stride = common_hal_sharpdisplay_framebuffer_get_row_stride(self);
         int height = common_hal_sharpdisplay_framebuffer_get_height(self);
         self->bufinfo.len = row_stride * height + 2;
-        supervisor_allocation *alloc = allocate_memory(align32_size(self->bufinfo.len), false, true);
+        self->bufinfo.buf = port_malloc(self->bufinfo.len, false);
-        if (alloc == NULL) {
+        if (self->bufinfo.buf == NULL) {
             m_malloc_fail(self->bufinfo.len);
         }
-        self->bufinfo.buf = alloc->ptr;
+        memset(self->bufinfo.buf, 0, self->bufinfo.len);
-        memset(alloc->ptr, 0, self->bufinfo.len);
 
         uint8_t *data = self->bufinfo.buf;
         if (self->jdi_display) {
@@ -136,7 +131,7 @@ void common_hal_sharpdisplay_framebuffer_deinit(sharpdisplay_framebuffer_obj_t *
 
     common_hal_reset_pin(self->chip_select.pin);
 
-    free_memory(allocation_from_ptr(self->bufinfo.buf));
+    port_free(self->bufinfo.buf);
 
     memset(self, 0, sizeof(*self));
 }

shared-module/supervisor/__init__.c

@@ -35,3 +35,12 @@ supervisor_status_bar_obj_t shared_module_supervisor_status_bar_obj = {
         .type = &supervisor_status_bar_type,
     },
 };
+
+// String of the last traceback.
+char *prev_traceback_string = NULL;
+
+// Custom settings for next code run.
+supervisor_next_code_info_t *next_code_configuration = NULL;
+
+// Custom USB settings.
+usb_identification_t *custom_usb_identification = NULL;

shared-module/usb_cdc/__init__.c

@@ -36,8 +36,7 @@
 #include "tusb.h"
 
 #if CIRCUITPY_USB_VENDOR
-// todo - this doesn't feel like it should be here.
+#include "supervisor/port.h"
-#include "supervisor/memory.h"
 #endif
 
 #if CFG_TUD_CDC != 2
@@ -370,27 +369,25 @@ size_t usb_vendor_descriptor_length(void) {
     return sizeof(usb_vendor_descriptor_template);
 }
 
-static supervisor_allocation *ms_os_20_descriptor_allocation;
+static uint8_t *ms_os_20_descriptor = NULL;
 
 size_t vendor_ms_os_20_descriptor_length() {
-    return sizeof(ms_os_20_descriptor_template);
+    return ms_os_20_descriptor != NULL ? sizeof(ms_os_20_descriptor_template) : 0;
 }
 uint8_t const *vendor_ms_os_20_descriptor() {
-    return (uint8_t *)ms_os_20_descriptor_allocation->ptr;
+    return ms_os_20_descriptor;
 }
 
-
 size_t usb_vendor_add_descriptor(uint8_t *descriptor_buf, descriptor_counts_t *descriptor_counts, uint8_t *current_interface_string) {
-
+    if (ms_os_20_descriptor == NULL) {
-    if (ms_os_20_descriptor_template[MS_OS_20_ITF_NUM_OFFSET] == MS_OS_20_ITF_NUM_MAGIC) {
+        ms_os_20_descriptor = port_malloc(sizeof(ms_os_20_descriptor_template), false);
-        ms_os_20_descriptor_allocation =
+        if (ms_os_20_descriptor == NULL) {
-            allocate_memory(align32_size(sizeof(ms_os_20_descriptor_template)),
+            return 0;
-                /*high_address*/ false, /*movable*/ false);
+        }
-        uint8_t *ms_os_20_descriptor_buf = (uint8_t *)ms_os_20_descriptor_allocation->ptr;
+        memcpy(ms_os_20_descriptor, ms_os_20_descriptor_template, sizeof(ms_os_20_descriptor_template));
-        memcpy(ms_os_20_descriptor_buf, ms_os_20_descriptor_template, sizeof(ms_os_20_descriptor_template));
+        ms_os_20_descriptor[MS_OS_20_ITF_NUM_OFFSET] = descriptor_counts->current_interface;
-        ms_os_20_descriptor_buf[MS_OS_20_ITF_NUM_OFFSET] = descriptor_counts->current_interface;
+        ms_os_20_descriptor[VENDOR_IN_ENDPOINT_INDEX] = 0x80 | descriptor_counts->current_endpoint;
-        ms_os_20_descriptor_buf[VENDOR_IN_ENDPOINT_INDEX] = 0x80 | descriptor_counts->current_endpoint;
+        ms_os_20_descriptor[VENDOR_OUT_ENDPOINT_INDEX] = descriptor_counts->current_endpoint;
-        ms_os_20_descriptor_buf[VENDOR_OUT_ENDPOINT_INDEX] = descriptor_counts->current_endpoint;
     }
 
     memcpy(descriptor_buf, usb_vendor_descriptor_template, sizeof(usb_vendor_descriptor_template));
@@ -411,7 +408,4 @@ size_t usb_vendor_add_descriptor(uint8_t *descriptor_buf, descriptor_counts_t *d
     return sizeof(usb_vendor_descriptor_template);
 }
 
-
-
-
 #endif

shared-module/usb_hid/__init__.c

@@ -32,7 +32,7 @@
 #include "py/runtime.h"
 #include "shared-bindings/usb_hid/__init__.h"
 #include "shared-bindings/usb_hid/Device.h"
-#include "supervisor/memory.h"
+#include "supervisor/port.h"
 #include "supervisor/usb.h"
 
 static const uint8_t usb_hid_descriptor_template[] = {
@@ -78,7 +78,7 @@ static const uint8_t usb_hid_descriptor_template[] = {
 
 #define MAX_HID_DEVICES 8
 
-static supervisor_allocation *hid_report_descriptor_allocation;
+static uint8_t *hid_report_descriptor = NULL;
 static usb_hid_device_obj_t hid_devices[MAX_HID_DEVICES];
 // If 0, USB HID is disabled.
 static mp_int_t num_hid_devices;
@@ -270,12 +270,17 @@ size_t usb_hid_report_descriptor_length(void) {
 }
 
 // Build the combined HID report descriptor in the given space.
-void usb_hid_build_report_descriptor(uint8_t *report_descriptor_space, size_t report_descriptor_length) {
+void usb_hid_build_report_descriptor(void) {
     if (!usb_hid_enabled()) {
         return;
     }
+    size_t report_length = usb_hid_report_descriptor_length();
+    hid_report_descriptor = port_malloc(report_length, false);
+    if (hid_report_descriptor == NULL) {
+        return;
+    }
 
-    uint8_t *report_descriptor_start = report_descriptor_space;
+    uint8_t *report_descriptor_start = hid_report_descriptor;
 
     for (mp_int_t i = 0; i < num_hid_devices; i++) {
         usb_hid_device_obj_t *device = &hid_devices[i];
@@ -291,23 +296,6 @@ void usb_hid_build_report_descriptor(uint8_t *report_descriptor_space, size_t re
     }
 }
 
-// Call this after the heap and VM are finished.
-void usb_hid_save_report_descriptor(uint8_t *report_descriptor_space, size_t report_descriptor_length) {
-    if (!usb_hid_enabled()) {
-        return;
-    }
-
-    // Allocate storage that persists across VMs to hold the combined report descriptor.
-    // and to remember the device details.
-
-    // Copy the descriptor from the temporary area to a supervisor storage allocation that
-    // will leave between VM instantiations.
-    hid_report_descriptor_allocation =
-        allocate_memory(align32_size(report_descriptor_length),
-            /*high_address*/ false, /*movable*/ false);
-    memcpy((uint8_t *)hid_report_descriptor_allocation->ptr, report_descriptor_space, report_descriptor_length);
-}
-
 void usb_hid_gc_collect(void) {
     gc_collect_ptr(hid_devices_tuple);
 
@@ -345,7 +333,7 @@ bool usb_hid_get_device_with_report_id(uint8_t report_id, usb_hid_device_obj_t *
 // Application returns pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
 uint8_t const *tud_hid_descriptor_report_cb(uint8_t itf) {
-    return (uint8_t *)hid_report_descriptor_allocation->ptr;
+    return (uint8_t *)hid_report_descriptor;
 }
 
 // Callback invoked when we receive a SET_PROTOCOL request.

shared-module/usb_hid/__init__.h

@@ -42,8 +42,7 @@ size_t usb_hid_report_descriptor_length(void);
 
 void usb_hid_setup_devices(void);
 size_t usb_hid_report_descriptor_length(void);
-void usb_hid_build_report_descriptor(uint8_t *report_descriptor_space, size_t report_descriptor_length);
+void usb_hid_build_report_descriptor(void);
-void usb_hid_save_report_descriptor(uint8_t *report_descriptor_space, size_t report_descriptor_length);
 
 bool usb_hid_get_device_with_report_id(uint8_t report_id, usb_hid_device_obj_t **device_out, size_t *id_idx_out);
 

shared-module/usb_midi/__init__.c

@@ -33,7 +33,6 @@
 #include "py/objtuple.h"
 #include "shared-bindings/usb_midi/PortIn.h"
 #include "shared-bindings/usb_midi/PortOut.h"
-#include "supervisor/memory.h"
 #include "supervisor/usb.h"
 #include "tusb.h"
 

supervisor/memory.h

@@ -1,77 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-// Basic allocations outside them for areas such as the VM heap and stack.
-// supervisor/shared/memory.c has a basic implementation for a continuous chunk of memory. Add it
-// to a SRC_ in a Makefile to use it.
-
-#ifndef MICROPY_INCLUDED_SUPERVISOR_MEMORY_H
-#define MICROPY_INCLUDED_SUPERVISOR_MEMORY_H
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <stddef.h>
-
-typedef struct {
-    uint32_t *ptr;
-} supervisor_allocation;
-
-
-
-void free_memory(supervisor_allocation *allocation);
-
-// Find the allocation with the given ptr, NULL if not found. When called from the context of a
-// supervisor_move_memory() callback, finds the allocation that had that ptr *before* the move, but
-// the returned allocation already contains the ptr after the move.
-// When called with NULL, may return either NULL or an unused allocation whose ptr is NULL (this is
-// a feature used internally in allocate_memory to save code size). Passing the return value to
-// free_memory() is a permissible no-op in either case.
-supervisor_allocation *allocation_from_ptr(void *ptr);
-
-supervisor_allocation *allocate_remaining_memory(void);
-
-// Allocate a piece of a given length in bytes. If high_address is true then it should be allocated
-// at a lower address from the top of the stack. Otherwise, addresses will increase starting after
-// statically allocated memory. If movable is false, memory will be taken from outside the GC heap
-// and will stay stationary until freed. While the VM is running, this will fail unless a previous
-// allocation of exactly matching length has recently been freed. If movable is true, memory will be
-// taken from either outside or inside the GC heap, and when the VM exits, will be moved outside.
-// The ptr of the returned supervisor_allocation will change at that point. If you need to be
-// notified of that, add your own callback function at the designated place near the end of
-// supervisor_move_memory().
-supervisor_allocation *allocate_memory(uint32_t length, bool high_address, bool movable);
-
-static inline size_t align32_size(size_t size) {
-    return (size + 3) & ~3;
-}
-
-size_t get_allocation_length(supervisor_allocation *allocation);
-
-// Called after the GC heap is freed, transfers movable allocations from the GC heap to the
-// supervisor heap and compacts the supervisor heap.
-void supervisor_move_memory(void);
-
-#endif  // MICROPY_INCLUDED_SUPERVISOR_MEMORY_H

supervisor/port.h

@@ -24,12 +24,11 @@
  * THE SOFTWARE.
  */
 
-#ifndef MICROPY_INCLUDED_SUPERVISOR_PORT_H
+#pragma once
-#define MICROPY_INCLUDED_SUPERVISOR_PORT_H
 
-#include "py/mpconfig.h"
+#include <stdbool.h>
+#include <stddef.h>
 
-#include "supervisor/memory.h"
 #include "supervisor/shared/safe_mode.h"
 
 // Provided by the linker;
@@ -43,11 +42,6 @@ extern uint32_t _ebss;
 
 safe_mode_t port_init(void);
 
-// If the port does not initialize the heap during port_init(), it must provide
-// this function which is called after CIRCUITPY is mounted.
-// If not required, a default (weak) implementation that does nothing is used.
-safe_mode_t port_heap_init(safe_mode_t);
-
 // Reset the microcontroller completely.
 void reset_cpu(void) NORETURN;
 
@@ -63,9 +57,6 @@ uint32_t *port_stack_get_limit(void);
 // Get stack top address
 uint32_t *port_stack_get_top(void);
 
-// True if stack is not located inside heap (at the top)
-bool port_has_fixed_stack(void);
-
 // Get heap bottom address
 uint32_t *port_heap_get_bottom(void);
 
@@ -137,5 +128,3 @@ void port_boot_info(void);
 // Some ports want to mark additional pointers as gc roots.
 // A default weak implementation is provided that does nothing.
 void port_gc_collect(void);
-
-#endif  // MICROPY_INCLUDED_SUPERVISOR_PORT_H

supervisor/port_heap.h

@@ -1,9 +1,9 @@
 /*
- * This file is part of the Micro Python project, http://micropython.org/
+ * This file is part of the MicroPython project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2021 Mark Komus
+ * Copyright (c) 2023 Scott Shawcroft for Adafruit Industries
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -27,9 +27,23 @@
 #pragma once
 
 #include <stdbool.h>
-#include "py/gc.h"
+#include <stddef.h>
-#include "py/misc.h"
-#include "supervisor/memory.h"
 
-extern void *common_hal_is31fl3741_allocator_impl(size_t sz);
+// Ports provide a heap for allocations that live outside the VM. The VM heap
-extern void common_hal_is31fl3741_free_impl(void *);
+// is allocated into it in split chunks. The supervisor provides a default heap
+// implementation for ports that don't have one of their own. Allocations done
+// to the outer heap *must* be explicitly managed. Only VM allocations are garbage
+// collected.
+
+// Called after port_init(). Ports can init the heap earlier in `port_init()` if
+// they need and leave this empty. Splitting this out allows us to provide a weak
+// implementation to use by default.
+void port_heap_init(void);
+
+void *port_malloc(size_t size, bool dma_capable);
+
+void port_free(void *ptr);
+
+void port_realloc(void *ptr, size_t size);
+
+size_t port_heap_get_largest_free_size(void);

supervisor/shared/background_callback.c

@@ -126,7 +126,7 @@ void background_callback_reset() {
     background_callback_t *cb = (background_callback_t *)callback_head;
     while (cb) {
         background_callback_t *next = cb->next;
-        if (!HEAP_PTR((void *)cb)) {
+        if (gc_ptr_on_heap((void *)cb)) {
             *previous_next = cb;
             previous_next = &cb->next;
             cb->next = NULL;

supervisor/shared/display.c

@@ -33,7 +33,6 @@
 #include "shared-bindings/displayio/Group.h"
 #include "shared-bindings/displayio/Palette.h"
 #include "shared-bindings/displayio/TileGrid.h"
-#include "supervisor/memory.h"
 
 #if CIRCUITPY_RGBMATRIX
 #include "shared-module/displayio/__init__.h"
@@ -49,6 +48,10 @@
 #include "supervisor/shared/status_bar.h"
 #endif
 
+#if CIRCUITPY_TERMINALIO
+#include "supervisor/port.h"
+#endif
+
 #if CIRCUITPY_REPL_LOGO
 extern uint32_t blinka_bitmap_data[];
 extern displayio_bitmap_t blinka_bitmap;
@@ -56,7 +59,8 @@ extern displayio_bitmap_t blinka_bitmap;
 extern displayio_group_t circuitpython_splash;
 
 #if CIRCUITPY_TERMINALIO
-static supervisor_allocation *tilegrid_tiles = NULL;
+static uint8_t *tilegrid_tiles = NULL;
+static size_t tilegrid_tiles_size = 0;
 #endif
 
 void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
@@ -89,14 +93,15 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
     }
     // Reuse the previous allocation if possible
     if (tilegrid_tiles) {
-        if (get_allocation_length(tilegrid_tiles) != align32_size(total_tiles)) {
+        if (tilegrid_tiles_size != total_tiles) {
-            free_memory(tilegrid_tiles);
+            port_free(tilegrid_tiles);
             tilegrid_tiles = NULL;
+            tilegrid_tiles_size = 0;
             reset_tiles = true;
         }
     }
     if (!tilegrid_tiles) {
-        tilegrid_tiles = allocate_memory(align32_size(total_tiles), false, true);
+        tilegrid_tiles = port_malloc(total_tiles, false);
         reset_tiles = true;
         if (!tilegrid_tiles) {
             return;
@@ -104,8 +109,6 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
     }
 
     if (reset_tiles) {
-        uint8_t *tiles = (uint8_t *)tilegrid_tiles->ptr;
-
         // Adjust the display dimensions to account for scale of the outer group.
         width_px /= scale;
         height_px /= scale;
@@ -127,7 +130,7 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
         // Right align the status bar.
         status_bar->x = width_px - status_bar->pixel_width;
         status_bar->top_left_y = 0;
-        status_bar->tiles = tiles;
+        status_bar->tiles = tilegrid_tiles;
         status_bar->full_change = true;
 
         scroll_area->width_in_tiles = width_in_tiles;
@@ -141,7 +144,7 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
         // Align the scroll area to the bottom so that the newest line isn't cutoff. The top line
         // may be clipped by the status bar and that's ok.
         scroll_area->y = height_px - scroll_area->pixel_height;
-        scroll_area->tiles = tiles + width_in_tiles;
+        scroll_area->tiles = tilegrid_tiles + width_in_tiles;
         scroll_area->full_change = true;
 
         common_hal_terminalio_terminal_construct(&supervisor_terminal, scroll_area, &supervisor_terminal_font, status_bar);
@@ -156,8 +159,9 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px) {
 void supervisor_stop_terminal(void) {
     #if CIRCUITPY_TERMINALIO
     if (tilegrid_tiles != NULL) {
-        free_memory(tilegrid_tiles);
+        port_free(tilegrid_tiles);
         tilegrid_tiles = NULL;
+        tilegrid_tiles_size = 0;
         supervisor_terminal_scroll_area_text_grid.tiles = NULL;
         supervisor_terminal_status_bar_text_grid.tiles = NULL;
         supervisor_terminal.scroll_area = NULL;
@@ -174,37 +178,6 @@ bool supervisor_terminal_started(void) {
     #endif
 }
 
-void supervisor_display_move_memory(void) {
-    #if CIRCUITPY_TERMINALIO
-    displayio_tilegrid_t *scroll_area = &supervisor_terminal_scroll_area_text_grid;
-    displayio_tilegrid_t *status_bar = &supervisor_terminal_status_bar_text_grid;
-    if (tilegrid_tiles != NULL) {
-        status_bar->tiles = (uint8_t *)tilegrid_tiles->ptr;
-        scroll_area->tiles = (uint8_t *)tilegrid_tiles->ptr + scroll_area->width_in_tiles;
-    } else {
-        scroll_area->tiles = NULL;
-        status_bar->tiles = NULL;
-    }
-    #endif
-
-    #if CIRCUITPY_DISPLAYIO
-    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
-        #if CIRCUITPY_RGBMATRIX
-        if (display_buses[i].rgbmatrix.base.type == &rgbmatrix_RGBMatrix_type) {
-            rgbmatrix_rgbmatrix_obj_t *pm = &display_buses[i].rgbmatrix;
-            common_hal_rgbmatrix_rgbmatrix_reconstruct(pm);
-        }
-        #endif
-        #if CIRCUITPY_SHARPDISPLAY
-        if (display_buses[i].bus_base.type == &sharpdisplay_framebuffer_type) {
-            sharpdisplay_framebuffer_obj_t *sharp = &display_buses[i].sharpdisplay;
-            common_hal_sharpdisplay_framebuffer_reconstruct(sharp);
-        }
-        #endif
-    }
-    #endif
-}
-
 #if CIRCUITPY_TERMINALIO
 #if CIRCUITPY_REPL_LOGO
 mp_obj_t members[] = { &supervisor_terminal_scroll_area_text_grid, &supervisor_blinka_sprite, &supervisor_terminal_status_bar_text_grid, };

supervisor/shared/display.h

@@ -56,6 +56,4 @@ void supervisor_start_terminal(uint16_t width_px, uint16_t height_px);
 void supervisor_stop_terminal(void);
 bool supervisor_terminal_started(void);
 
-void supervisor_display_move_memory(void);
-
 #endif  // MICROPY_INCLUDED_SUPERVISOR_SHARED_DISPLAY_H

supervisor/shared/external_flash/external_flash.c

@@ -29,17 +29,16 @@
 #include <string.h>
 #include "genhdr/devices.h"
 #include "supervisor/flash.h"
+#include "supervisor/port.h"
 #include "supervisor/spi_flash_api.h"
 #include "supervisor/shared/external_flash/common_commands.h"
 #include "extmod/vfs.h"
 #include "extmod/vfs_fat.h"
-#include "py/gc.h"
 #include "py/misc.h"
 #include "py/obj.h"
 #include "py/runtime.h"
 #include "lib/oofatfs/ff.h"
 #include "shared-bindings/microcontroller/__init__.h"
-#include "supervisor/memory.h"
 
 #define NO_SECTOR_LOADED 0xFFFFFFFF
 
@@ -55,7 +54,8 @@ static const external_flash_device *flash_device = NULL;
 // cache.
 static uint32_t dirty_mask;
 
-static supervisor_allocation *supervisor_cache = NULL;
+// Table of pointers to each cached block
+static uint8_t **flash_cache_table = NULL;
 
 // Wait until both the write enable and write in progress bits have cleared.
 static bool wait_for_flash_ready(void) {
@@ -295,7 +295,7 @@ void supervisor_flash_init(void) {
 
     current_sector = NO_SECTOR_LOADED;
     dirty_mask = 0;
-    MP_STATE_VM(flash_ram_cache) = NULL;
+    flash_cache_table = NULL;
 }
 
 // The size of each individual block.
@@ -352,47 +352,23 @@ static bool allocate_ram_cache(void) {
     uint8_t blocks_per_sector = SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE;
     uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
 
-    uint32_t table_size = blocks_per_sector * pages_per_block * sizeof(uint32_t);
+    uint32_t table_size = blocks_per_sector * pages_per_block * sizeof(size_t);
     // Attempt to allocate outside the heap first.
-    supervisor_cache = allocate_memory(table_size + SPI_FLASH_ERASE_SIZE, false, false);
+    flash_cache_table = port_malloc(table_size, false);
-    if (supervisor_cache != NULL) {
-        MP_STATE_VM(flash_ram_cache) = (uint8_t **)supervisor_cache->ptr;
-        uint8_t *page_start = (uint8_t *)supervisor_cache->ptr + table_size;
 
-        for (uint8_t i = 0; i < blocks_per_sector; i++) {
-            for (uint8_t j = 0; j < pages_per_block; j++) {
-                uint32_t offset = i * pages_per_block + j;
-                MP_STATE_VM(flash_ram_cache)[offset] = page_start + offset * SPI_FLASH_PAGE_SIZE;
-            }
-        }
-        return true;
-    }
-
-    // Couldn't allocate outside the heap. Is the heap available?
-    if (!gc_alloc_possible()) {
-        return false;
-    }
-
-    MP_STATE_VM(flash_ram_cache) = m_malloc_maybe(blocks_per_sector * pages_per_block * sizeof(uint32_t));
-    if (MP_STATE_VM(flash_ram_cache) == NULL) {
-        return false;
-    }
     // Declare i and j outside the loops in case we fail to allocate everything
     // we need. In that case we'll give it back.
     uint8_t i = 0;
     uint8_t j = 0;
-    bool success = true;
+    bool success = flash_cache_table != NULL;
-    for (i = 0; i < blocks_per_sector; i++) {
+    for (i = 0; i < blocks_per_sector && success; i++) {
-        for (j = 0; j < pages_per_block; j++) {
+        for (j = 0; j < pages_per_block && success; j++) {
-            uint8_t *page_cache = m_malloc_maybe(SPI_FLASH_PAGE_SIZE);
+            uint8_t *page_cache = port_malloc(SPI_FLASH_PAGE_SIZE, false);
             if (page_cache == NULL) {
                 success = false;
                 break;
             }
-            MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j] = page_cache;
+            flash_cache_table[i * pages_per_block + j] = page_cache;
-        }
-        if (!success) {
-            break;
         }
     }
     // We couldn't allocate enough so give back what we got.
@@ -402,24 +378,27 @@ static bool allocate_ram_cache(void) {
         i++;
         for (; i > 0; i--) {
             for (; j > 0; j--) {
-                m_free(MP_STATE_VM(flash_ram_cache)[(i - 1) * pages_per_block + (j - 1)]);
+                port_free(flash_cache_table[(i - 1) * pages_per_block + (j - 1)]);
             }
             j = pages_per_block;
         }
-        m_free(MP_STATE_VM(flash_ram_cache));
+        port_free(flash_cache_table);
-        MP_STATE_VM(flash_ram_cache) = NULL;
+        flash_cache_table = NULL;
     }
     return success;
 }
 
 static void release_ram_cache(void) {
-    if (supervisor_cache != NULL) {
+    uint8_t blocks_per_sector = SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE;
-        free_memory(supervisor_cache);
+    uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
-        supervisor_cache = NULL;
+    for (uint8_t i = 0; i < blocks_per_sector; i++) {
-    } else if (gc_alloc_possible()) {
+        for (uint8_t j = 0; j < pages_per_block; j++) {
-        m_free(MP_STATE_VM(flash_ram_cache));
+            uint32_t offset = i * pages_per_block + j;
+            port_free(flash_cache_table[offset]);
+        }
     }
-    MP_STATE_VM(flash_ram_cache) = NULL;
+    port_free(flash_cache_table);
+    flash_cache_table = NULL;
 }
 
 // Flush the cached sector from ram onto the flash. We'll free the cache unless
@@ -441,7 +420,7 @@ static bool flush_ram_cache(bool keep_cache) {
             for (uint8_t j = 0; j < pages_per_block; j++) {
                 copy_to_ram_ok = read_flash(
                     current_sector + (i * pages_per_block + j) * SPI_FLASH_PAGE_SIZE,
-                    MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j],
+                    flash_cache_table[i * pages_per_block + j],
                     SPI_FLASH_PAGE_SIZE);
                 if (!copy_to_ram_ok) {
                     break;
@@ -462,11 +441,8 @@ static bool flush_ram_cache(bool keep_cache) {
     for (uint8_t i = 0; i < SPI_FLASH_ERASE_SIZE / FILESYSTEM_BLOCK_SIZE; i++) {
         for (uint8_t j = 0; j < pages_per_block; j++) {
             write_flash(current_sector + (i * pages_per_block + j) * SPI_FLASH_PAGE_SIZE,
-                MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j],
+                flash_cache_table[i * pages_per_block + j],
                 SPI_FLASH_PAGE_SIZE);
-            if (!keep_cache && supervisor_cache == NULL && gc_alloc_possible()) {
-                m_free(MP_STATE_VM(flash_ram_cache)[i * pages_per_block + j]);
-            }
         }
     }
     // We're done with the cache for now so give it back.
@@ -483,7 +459,7 @@ static void spi_flash_flush_keep_cache(bool keep_cache) {
     port_pin_set_output_level(MICROPY_HW_LED_MSC, true);
     #endif
     // If we've cached to the flash itself flush from there.
-    if (MP_STATE_VM(flash_ram_cache) == NULL) {
+    if (flash_cache_table == NULL) {
         flush_scratch_flash();
     } else {
         flush_ram_cache(keep_cache);
@@ -524,11 +500,11 @@ static bool external_flash_read_block(uint8_t *dest, uint32_t block) {
     uint8_t mask = 1 << (block_index);
     // We're reading from the currently cached sector.
     if (current_sector == this_sector && (mask & dirty_mask) > 0) {
-        if (MP_STATE_VM(flash_ram_cache) != NULL) {
+        if (flash_cache_table != NULL) {
             uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
             for (int i = 0; i < pages_per_block; i++) {
                 memcpy(dest + i * SPI_FLASH_PAGE_SIZE,
-                    MP_STATE_VM(flash_ram_cache)[block_index * pages_per_block + i],
+                    flash_cache_table[block_index * pages_per_block + i],
                     SPI_FLASH_PAGE_SIZE);
             }
             return true;
@@ -564,7 +540,7 @@ static bool external_flash_write_block(const uint8_t *data, uint32_t block) {
         if (current_sector != NO_SECTOR_LOADED) {
             supervisor_flash_flush();
         }
-        if (MP_STATE_VM(flash_ram_cache) == NULL && !allocate_ram_cache()) {
+        if (flash_cache_table == NULL && !allocate_ram_cache()) {
             erase_sector(flash_device->total_size - SPI_FLASH_ERASE_SIZE);
             wait_for_flash_ready();
         }
@@ -573,10 +549,10 @@ static bool external_flash_write_block(const uint8_t *data, uint32_t block) {
     }
     dirty_mask |= mask;
     // Copy the block to the appropriate cache.
-    if (MP_STATE_VM(flash_ram_cache) != NULL) {
+    if (flash_cache_table != NULL) {
         uint8_t pages_per_block = FILESYSTEM_BLOCK_SIZE / SPI_FLASH_PAGE_SIZE;
         for (int i = 0; i < pages_per_block; i++) {
-            memcpy(MP_STATE_VM(flash_ram_cache)[block_index * pages_per_block + i],
+            memcpy(flash_cache_table[block_index * pages_per_block + i],
                 data + i * SPI_FLASH_PAGE_SIZE,
                 SPI_FLASH_PAGE_SIZE);
         }
@@ -607,5 +583,3 @@ mp_uint_t supervisor_flash_write_blocks(const uint8_t *src, uint32_t block_num,
 
 void MP_WEAK external_flash_setup(void) {
 }
-
-MP_REGISTER_ROOT_POINTER(uint8_t * *flash_ram_cache);

supervisor/shared/memory.c

@@ -1,350 +0,0 @@
-/*
- * This file is part of the MicroPython project, http://micropython.org/
- *
- * The MIT License (MIT)
- *
- * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "supervisor/memory.h"
-#include "supervisor/port.h"
-
-#include <string.h>
-
-#include "py/gc.h"
-#include "supervisor/shared/display.h"
-
-enum {
-    CIRCUITPY_SUPERVISOR_IMMOVABLE_ALLOC_COUNT =
-        0
-        // stack + heap
-        + 2
-
-        #if INTERNAL_FLASH_FILESYSTEM == 0
-        + 1
-        #endif
-
-        #if CIRCUITPY_USB
-        + 1 // device_descriptor_allocation
-        + 1 // configuration_descriptor_allocation
-        + 1 // string_descriptors_allocation
-        #endif
-
-        #if CIRCUITPY_USB_HID
-        + 1 // hid_report_descriptor_allocation
-        + 1 // hid_devices_allocation
-        #endif
-
-        #if CIRCUITPY_USB_VENDOR
-        + 1  // usb_vendor_add_descriptor
-        #endif
-
-        + CIRCUITPY_PORT_NUM_SUPERVISOR_ALLOCATIONS
-        #if CIRCUITPY_AUDIOBUSIO_PDMIN
-        + 1
-        #endif
-    ,
-
-    CIRCUITPY_SUPERVISOR_MOVABLE_ALLOC_COUNT =
-        0
-        // next_code_allocation
-        + 1
-        // prev_traceback_allocation
-        + 1
-        #if CIRCUITPY_DISPLAYIO
-        #if CIRCUITPY_TERMINALIO
-        + 1
-        #endif
-        + CIRCUITPY_DISPLAY_LIMIT * (
-            // Maximum needs of one display: max(4 if RGBMATRIX, 1 if SHARPDISPLAY, 0)
-            #if CIRCUITPY_RGBMATRIX
-            4
-            #elif CIRCUITPY_PICODVI
-            2
-            #elif CIRCUITPY_SHARPDISPLAY
-            1
-            #else
-            0
-            #endif
-            )
-        #endif
-    ,
-
-    CIRCUITPY_SUPERVISOR_ALLOC_COUNT = CIRCUITPY_SUPERVISOR_IMMOVABLE_ALLOC_COUNT + CIRCUITPY_SUPERVISOR_MOVABLE_ALLOC_COUNT
-};
-
-// The lowest two bits of a valid length are always zero, so we can use them to mark an allocation
-// as a hole (freed by the client but not yet reclaimed into the free middle) and as movable.
-#define FLAGS 3
-#define HOLE 1
-#define MOVABLE 2
-
-static supervisor_allocation allocations[CIRCUITPY_SUPERVISOR_ALLOC_COUNT];
-supervisor_allocation *old_allocations;
-
-typedef struct _supervisor_allocation_node {
-    struct _supervisor_allocation_node *next;
-    size_t length;
-    // We use uint32_t to ensure word (4 byte) alignment.
-    uint32_t data[];
-} supervisor_allocation_node;
-
-supervisor_allocation_node *low_head;
-supervisor_allocation_node *high_head;
-
-// Intermediate (void*) is to suppress -Wcast-align warning. Alignment will always be correct
-// because this only reverses how (alloc)->ptr was obtained as &(node->data[0]).
-#define ALLOCATION_NODE(alloc) ((supervisor_allocation_node *)(void *)((char *)((alloc)->ptr) - sizeof(supervisor_allocation_node)))
-
-void free_memory(supervisor_allocation *allocation) {
-    if (allocation == NULL || allocation->ptr == NULL) {
-        return;
-    }
-    supervisor_allocation_node *node = ALLOCATION_NODE(allocation);
-    if (node == low_head) {
-        do {
-            low_head = low_head->next;
-        } while (low_head != NULL && (low_head->length & HOLE));
-    } else if (node == high_head) {
-        do {
-            high_head = high_head->next;
-        } while (high_head != NULL && (high_head->length & HOLE));
-    } else {
-        // Check if it's in the list of embedded allocations.
-        supervisor_allocation_node **emb = &MP_STATE_VM(first_embedded_allocation);
-        while (*emb != NULL && *emb != node) {
-            emb = &((*emb)->next);
-        }
-        if (*emb != NULL) {
-            // Found, remove it from the list.
-            *emb = node->next;
-            m_free(node
-                #if MICROPY_MALLOC_USES_ALLOCATED_SIZE
-                , sizeof(supervisor_allocation_node) + (node->length & ~FLAGS)
-                #endif
-                );
-        } else {
-            // Else it must be within the low or high ranges and becomes a hole.
-            node->length = ((node->length & ~FLAGS) | HOLE);
-        }
-    }
-    allocation->ptr = NULL;
-}
-
-supervisor_allocation *allocation_from_ptr(void *ptr) {
-    // When called from the context of supervisor_move_memory() (old_allocations != NULL), search
-    // by old pointer to give clients a way of mapping from old to new pointer. But not if
-    // ptr == NULL, then the caller wants an allocation whose current ptr is NULL.
-    supervisor_allocation *list = (old_allocations && ptr) ? old_allocations : &allocations[0];
-    for (size_t index = 0; index < CIRCUITPY_SUPERVISOR_ALLOC_COUNT; index++) {
-        if (list[index].ptr == ptr) {
-            return &allocations[index];
-        }
-    }
-    return NULL;
-}
-
-supervisor_allocation *allocate_remaining_memory(void) {
-    return allocate_memory((uint32_t)-1, false, false);
-}
-
-static supervisor_allocation_node *find_hole(supervisor_allocation_node *node, size_t length) {
-    for (; node != NULL; node = node->next) {
-        if (node->length == (length | HOLE)) {
-            break;
-        }
-    }
-    return node;
-}
-
-static supervisor_allocation_node *allocate_memory_node(uint32_t length, bool high, bool movable) {
-    if (CIRCUITPY_SUPERVISOR_MOVABLE_ALLOC_COUNT == 0) {
-        assert(!movable);
-    }
-    // supervisor_move_memory() currently does not support movable allocations on the high side, it
-    // must be extended first if this is ever needed.
-    assert(!(high && movable));
-    uint32_t *low_address = low_head ? low_head->data + low_head->length / 4 : port_heap_get_bottom();
-    uint32_t *high_address = high_head ? (uint32_t *)high_head : port_heap_get_top();
-    // Special case for allocate_remaining_memory(), avoids computing low/high_address twice.
-    if (length == (uint32_t)-1) {
-        length = (high_address - low_address) * 4 - sizeof(supervisor_allocation_node);
-    }
-    if (length == 0 || length % 4 != 0) {
-        return NULL;
-    }
-    // 1. Matching hole on the requested side?
-    supervisor_allocation_node *node = find_hole(high ? high_head : low_head, length);
-    if (!node) {
-        // 2. Enough free space in the middle?
-        if ((high_address - low_address) * 4 >= (int32_t)(sizeof(supervisor_allocation_node) + length)) {
-            if (high) {
-                high_address -= (sizeof(supervisor_allocation_node) + length) / 4;
-                node = (supervisor_allocation_node *)high_address;
-                node->next = high_head;
-                high_head = node;
-            } else {
-                node = (supervisor_allocation_node *)low_address;
-                node->next = low_head;
-                low_head = node;
-            }
-        } else {
-            // 3. Matching hole on the other side?
-            node = find_hole(high ? low_head : high_head, length);
-            if (!node) {
-                // 4. GC allocation?
-                if (movable && gc_alloc_possible()) {
-                    node = m_malloc_maybe(sizeof(supervisor_allocation_node) + length);
-                    if (node) {
-                        node->next = MP_STATE_VM(first_embedded_allocation);
-                        MP_STATE_VM(first_embedded_allocation) = node;
-                    }
-                }
-                if (!node) {
-                    // 5. Give up.
-                    return NULL;
-                }
-            }
-        }
-    }
-    node->length = length;
-    if (movable) {
-        node->length |= MOVABLE;
-    }
-    return node;
-}
-
-supervisor_allocation *allocate_memory(uint32_t length, bool high, bool movable) {
-    supervisor_allocation_node *node = allocate_memory_node(length, high, movable);
-    if (!node) {
-        return NULL;
-    }
-    // Find the first free allocation.
-    supervisor_allocation *alloc = allocation_from_ptr(NULL);
-    if (!alloc) {
-        // We should free node again to avoid leaking, but something is wrong anyway if clients try
-        // to make more allocations than available, so don't bother.
-        return NULL;
-    }
-    alloc->ptr = &(node->data[0]);
-    return alloc;
-}
-
-size_t get_allocation_length(supervisor_allocation *allocation) {
-    return ALLOCATION_NODE(allocation)->length & ~FLAGS;
-}
-
-
-void supervisor_move_memory(void) {
-    // This whole function is not needed when there are no movable allocations, let it be optimized
-    // out.
-    if (CIRCUITPY_SUPERVISOR_MOVABLE_ALLOC_COUNT == 0) {
-        return;
-    }
-    // This must be called exactly after freeing the heap, so that the embedded allocations, if any,
-    // are now in the free region.
-    assert(MP_STATE_VM(first_embedded_allocation) == NULL || (
-        (low_head == NULL || low_head < MP_STATE_VM(first_embedded_allocation)) &&
-        (high_head == NULL || MP_STATE_VM(first_embedded_allocation) < high_head)));
-
-    // Save the old pointers for allocation_from_ptr().
-    supervisor_allocation old_allocations_array[CIRCUITPY_SUPERVISOR_ALLOC_COUNT];
-    memcpy(old_allocations_array, allocations, sizeof(allocations));
-
-    // Compact the low side. Traverse the list repeatedly, finding movable allocations preceded by a
-    // hole and swapping them, until no more are found. This is not the most runtime-efficient way,
-    // but probably the shortest and simplest code.
-    bool acted;
-    do {
-        acted = false;
-        supervisor_allocation_node **nodep = &low_head;
-        while (*nodep != NULL && (*nodep)->next != NULL) {
-            if (((*nodep)->length & MOVABLE) && ((*nodep)->next->length & HOLE)) {
-                supervisor_allocation_node *oldnode = *nodep;
-                supervisor_allocation_node *start = oldnode->next;
-                supervisor_allocation *alloc = allocation_from_ptr(&(oldnode->data[0]));
-                assert(alloc != NULL);
-                alloc->ptr = &(start->data[0]);
-                oldnode->next = start->next;
-                size_t holelength = start->length;
-                size_t size = sizeof(supervisor_allocation_node) + (oldnode->length & ~FLAGS);
-                memmove(start, oldnode, size);
-                supervisor_allocation_node *newhole = (supervisor_allocation_node *)(void *)((char *)start + size);
-                newhole->next = start;
-                newhole->length = holelength;
-                *nodep = newhole;
-                acted = true;
-            }
-            nodep = &((*nodep)->next);
-        }
-    } while (acted);
-    // Any holes bubbled to the top can be absorbed into the free middle.
-    while (low_head != NULL && (low_head->length & HOLE)) {
-        low_head = low_head->next;
-    }
-    ;
-
-    // Don't bother compacting the high side, there are no movable allocations and no holes there in
-    // current usage.
-
-    // Promote the embedded allocations to top-level ones, compacting them at the beginning of the
-    // now free region (or possibly in matching holes).
-    // The linked list is unordered, but allocations must be processed in order to avoid risking
-    // overwriting each other. To that end, repeatedly find the lowest element of the list, remove
-    // it from the list, and process it. This ad-hoc selection sort results in substantially shorter
-    // code than using the qsort() function from the C library.
-    while (MP_STATE_VM(first_embedded_allocation)) {
-        // First element is first candidate.
-        supervisor_allocation_node **pminnode = &MP_STATE_VM(first_embedded_allocation);
-        // Iterate from second element (if any) on.
-        for (supervisor_allocation_node **pnode = &(MP_STATE_VM(first_embedded_allocation)->next); *pnode != NULL; pnode = &(*pnode)->next) {
-            if (*pnode < *pminnode) {
-                pminnode = pnode;
-            }
-        }
-        // Remove from list.
-        supervisor_allocation_node *node = *pminnode;
-        *pminnode = node->next;
-        // Process.
-        size_t length = (node->length & ~FLAGS);
-        supervisor_allocation *alloc = allocation_from_ptr(&(node->data[0]));
-        assert(alloc != NULL);
-        // This may overwrite the header of node if it happened to be there already, but not the
-        // data.
-        supervisor_allocation_node *new_node = allocate_memory_node(length, false, true);
-        // There must be enough free space.
-        assert(new_node != NULL);
-        memmove(&(new_node->data[0]), &(node->data[0]), length);
-        alloc->ptr = &(new_node->data[0]);
-    }
-
-    // Notify clients that their movable allocations may have moved.
-    old_allocations = &old_allocations_array[0];
-
-    #if CIRCUITPY_DISPLAYIO
-    supervisor_display_move_memory();
-    #endif
-
-    // Add calls to further clients here.
-    old_allocations = NULL;
-}
-
-MP_REGISTER_ROOT_POINTER(struct _supervisor_allocation_node *first_embedded_allocation);

supervisor/shared/port.c

@@ -26,6 +26,14 @@
 
 #include "supervisor/port.h"
 
+#include <string.h>
+
+#include "py/runtime.h"
+
+#include "lib/tlsf/tlsf.h"
+
+static tlsf_t heap;
+
 MP_WEAK void port_wake_main_task(void) {
 }
 
@@ -37,3 +45,37 @@ MP_WEAK void port_yield(void) {
 
 MP_WEAK void port_boot_info(void) {
 }
+
+MP_WEAK void port_heap_init(void) {
+    uint32_t *heap_bottom = port_heap_get_bottom();
+    uint32_t *heap_top = port_heap_get_top();
+    size_t size = (heap_top - heap_bottom) * sizeof(uint32_t);
+    heap = tlsf_create_with_pool(heap_bottom, size, size);
+}
+
+MP_WEAK void *port_malloc(size_t size, bool dma_capable) {
+    void *block = tlsf_malloc(heap, size);
+    return block;
+}
+
+MP_WEAK void port_free(void *ptr) {
+    tlsf_free(heap, ptr);
+}
+
+MP_WEAK void port_realloc(void *ptr, size_t size) {
+    tlsf_realloc(heap, ptr, size);
+}
+
+static void max_size_walker(void *ptr, size_t size, int used, void *user) {
+    size_t *max_size = (size_t *)user;
+    if (!used && *max_size < size) {
+        *max_size = size;
+    }
+}
+
+MP_WEAK size_t port_heap_get_largest_free_size(void) {
+    size_t max_size = 0;
+    tlsf_walk_pool(tlsf_get_pool(heap), max_size_walker, &max_size);
+    // IDF does this. Not sure why.
+    return tlsf_fit_size(heap, max_size);
+}

supervisor/shared/reload.c

@@ -32,7 +32,6 @@
 #include "supervisor/shared/reload.h"
 #include "supervisor/shared/tick.h"
 
-supervisor_allocation *next_code_allocation;
 #include "shared-bindings/supervisor/Runtime.h"
 
 // True if user has disabled autoreload.

supervisor/shared/reload.h

@@ -27,7 +27,6 @@
 #ifndef MICROPY_INCLUDED_SUPERVISOR_AUTORELOAD_H
 #define MICROPY_INCLUDED_SUPERVISOR_AUTORELOAD_H
 
-#include "supervisor/memory.h"
 #include "py/obj.h"
 #include "shared-bindings/supervisor/RunReason.h"
 
@@ -47,13 +46,6 @@ enum {
     AUTORELOAD_SUSPEND_WEB = 0x8
 };
 
-typedef struct {
-    uint8_t options;
-    char filename[];
-} next_code_info_t;
-
-extern supervisor_allocation *next_code_allocation;
-
 // Helper for exiting the VM and reloading immediately.
 void reload_initiate(supervisor_run_reason_t run_reason);
 

supervisor/shared/safe_mode.c

@@ -218,7 +218,7 @@ void print_safe_mode_message(safe_mode_t reason) {
                 message = MP_ERROR_TEXT("NLR jump failed. Likely memory corruption.");
                 break;
             case SAFE_MODE_NO_HEAP:
-                message = MP_ERROR_TEXT("Unable to allocate the heap.");
+                message = MP_ERROR_TEXT("Unable to allocate to the heap.");
                 break;
             case SAFE_MODE_SDK_FATAL_ERROR:
                 message = MP_ERROR_TEXT("Third-party firmware fatal error.");

supervisor/shared/stack.c

@@ -32,48 +32,14 @@
 #include "supervisor/port.h"
 #include "supervisor/shared/safe_mode.h"
 
-extern uint32_t _estack;
+void stack_init(void) {
-
+    uint32_t *stack_limit = port_stack_get_limit();
-// Requested 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;
-static size_t stack_length = 0;
-
-#define EXCEPTION_STACK_SIZE 1024
-
-static void allocate_stack(void) {
-
-    if (port_has_fixed_stack()) {
-        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);
-            current_stack_size = CIRCUITPY_DEFAULT_STACK_SIZE;
-        } else {
-            current_stack_size = next_stack_size;
-        }
-        stack_limit = stack_alloc->ptr;
-        stack_length = get_allocation_length(stack_alloc);
-    }
-
     *stack_limit = STACK_CANARY_VALUE;
 }
 
 inline bool stack_ok(void) {
-    return stack_limit == NULL || *stack_limit == STACK_CANARY_VALUE;
+    uint32_t *stack_limit = port_stack_get_limit();
+    return *stack_limit == STACK_CANARY_VALUE;
 }
 
 inline void assert_heap_ok(void) {
@@ -81,44 +47,3 @@ inline void assert_heap_ok(void) {
         reset_into_safe_mode(SAFE_MODE_STACK_OVERFLOW);
     }
 }
-
-void stack_init(void) {
-    allocate_stack();
-}
-
-void stack_resize(void) {
-    if (stack_limit == NULL) {
-        return;
-    }
-    if (next_stack_size == current_stack_size) {
-        *stack_limit = STACK_CANARY_VALUE;
-        return;
-    }
-    free_memory(allocation_from_ptr(stack_limit));
-    stack_limit = NULL;
-    allocate_stack();
-}
-
-uint32_t *stack_get_bottom(void) {
-    return stack_limit;
-}
-
-size_t stack_get_length(void) {
-    return stack_length;
-}
-
-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) {
-    return next_stack_size;
-}
-
-uint32_t get_current_stack_size(void) {
-    return current_stack_size;
-}

supervisor/shared/stack.h

@@ -24,22 +24,16 @@
  * THE SOFTWARE.
  */
 
-#ifndef MICROPY_INCLUDED_SUPERVISOR_STACK_H
+#pragma once
-#define MICROPY_INCLUDED_SUPERVISOR_STACK_H
 
+#include <stdbool.h>
 #include <stddef.h>
-
+#include <stdint.h>
-#include "supervisor/memory.h"
 
 void stack_init(void);
-void stack_resize(void);
 // Actual stack location and size, may be larger than requested.
 uint32_t *stack_get_bottom(void);
 size_t stack_get_length(void);
-// Next/current requested stack 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);
 
 // Use this after any calls into a library which may use a lot of stack. This will raise a Python
@@ -49,5 +43,3 @@ void assert_heap_ok(void);
 #ifndef STACK_CANARY_VALUE
 #define STACK_CANARY_VALUE 0x017829ef
 #endif
-
-#endif  // MICROPY_INCLUDED_SUPERVISOR_STACK_H

supervisor/shared/traceback.c

@@ -25,5 +25,3 @@
  */
 
 #include "traceback.h"
-
-supervisor_allocation *prev_traceback_allocation;

supervisor/shared/traceback.h

@@ -27,8 +27,4 @@
 #ifndef MICROPY_INCLUDED_SUPERVISOR_TRACEBACK_H
 #define MICROPY_INCLUDED_SUPERVISOR_TRACEBACK_H
 
-#include "supervisor/memory.h"
-
-extern supervisor_allocation *prev_traceback_allocation;
-
 #endif  // MICROPY_INCLUDED_SUPERVISOR_TRACEBACK_H

supervisor/shared/usb/usb.c

@@ -27,6 +27,7 @@
 #include "py/objstr.h"
 #include "py/runtime.h"
 #include "shared-bindings/microcontroller/Processor.h"
+#include "shared-bindings/supervisor/__init__.h"
 #include "supervisor/background_callback.h"
 #include "supervisor/port.h"
 #include "supervisor/serial.h"
@@ -85,7 +86,27 @@ MP_WEAK void post_usb_init(void) {
 }
 
 void usb_init(void) {
+
+    usb_identification_t defaults;
+    usb_identification_t *identification;
+    if (custom_usb_identification != NULL) {
+        identification = custom_usb_identification;
+    } else {
+        // This compiles to less code than using a struct initializer.
+        defaults.vid = USB_VID;
+        defaults.pid = USB_PID;
+        strcpy(defaults.manufacturer_name, USB_MANUFACTURER);
+        strcpy(defaults.product_name, USB_PRODUCT);
+        identification = &defaults;
+        // This memory only needs to be live through the end of usb_build_descriptors.
+    }
+    if (!usb_build_descriptors(identification)) {
+        return;
+    }
     init_usb_hardware();
+    #if CIRCUITPY_USB_HID
+    usb_hid_build_report_descriptor();
+    #endif
 
     // Only init device. Host gets inited by the `usb_host` module common-hal.
     tud_init(TUD_OPT_RHPORT);
@@ -123,66 +144,6 @@ void usb_set_defaults(void) {
     #endif
 };
 
-#if CIRCUITPY_USB_IDENTIFICATION
-supervisor_allocation *usb_identification_allocation = NULL;
-#endif
-
-// Some dynamic USB data must be saved after boot.py. How much is needed?
-size_t usb_boot_py_data_size(void) {
-    size_t size = sizeof(usb_identification_t);
-
-    #if CIRCUITPY_USB_HID
-    size += usb_hid_report_descriptor_length();
-    #endif
-
-    return size;
-}
-
-// Fill in the data to save.
-void usb_get_boot_py_data(uint8_t *temp_storage, size_t temp_storage_size) {
-    #if CIRCUITPY_USB_IDENTIFICATION
-    if (usb_identification_allocation) {
-        memcpy(temp_storage, usb_identification_allocation->ptr, sizeof(usb_identification_t));
-        free_memory(usb_identification_allocation);
-    }
-    #else
-    if (false) {
-    }
-    #endif
-    else {
-        usb_identification_t defaults;
-        // This compiles to less code than using a struct initializer.
-        defaults.vid = USB_VID;
-        defaults.pid = USB_PID;
-        strcpy(defaults.manufacturer_name, USB_MANUFACTURER);
-        strcpy(defaults.product_name, USB_PRODUCT);
-        memcpy(temp_storage, &defaults, sizeof(defaults));
-    }
-
-    temp_storage += sizeof(usb_identification_t);
-    temp_storage_size -= sizeof(usb_identification_t);
-
-    #if CIRCUITPY_USB_HID
-    usb_hid_build_report_descriptor(temp_storage, temp_storage_size);
-    #endif
-}
-
-// After VM is gone, save data into non-heap storage (storage_allocations).
-void usb_return_boot_py_data(uint8_t *temp_storage, size_t temp_storage_size) {
-    usb_identification_t identification;
-    memcpy(&identification, temp_storage, sizeof(usb_identification_t));
-
-    temp_storage += sizeof(usb_identification_t);
-    temp_storage_size -= sizeof(usb_identification_t);
-
-    #if CIRCUITPY_USB_HID
-    usb_hid_save_report_descriptor(temp_storage, temp_storage_size);
-    #endif
-
-    // Now we can also build the rest of the descriptors and place them in storage_allocations.
-    usb_build_descriptors(&identification);
-}
-
 // Call this when ready to run code.py or a REPL, and a VM has been started.
 void usb_setup_with_vm(void) {
     #if CIRCUITPY_USB_HID

supervisor/shared/usb/usb_desc.c

@@ -28,7 +28,7 @@
 
 #include "py/objstr.h"
 #include "py/runtime.h"
-#include "supervisor/memory.h"
+#include "supervisor/port.h"
 #include "supervisor/shared/safe_mode.h"
 #include "supervisor/usb.h"
 
@@ -64,14 +64,13 @@ static interface_string_t collected_interface_strings[MAX_INTERFACE_STRINGS];
 static size_t collected_interface_strings_length;
 static uint8_t current_interface_string;
 
-static supervisor_allocation *device_descriptor_allocation;
+static uint8_t *device_descriptor;
-static supervisor_allocation *configuration_descriptor_allocation;
+static uint8_t *configuration_descriptor;
-static supervisor_allocation *string_descriptors_allocation;
+static uint16_t *string_descriptors;
 
 // Serial number string is UID length * 2 (2 nibbles per byte) + 1 byte for null termination.
 static char serial_number_hex_string[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH * 2 + 1];
 
-
 static const uint8_t device_descriptor_template[] = {
     0x12,        //  0 bLength
     0x01,        //  1 bDescriptorType (Device)
@@ -110,11 +109,13 @@ static const uint8_t configuration_descriptor_template[] = {
     0x32,        // 8 bMaxPower 100mA
 };
 
-static void usb_build_device_descriptor(const usb_identification_t *identification) {
+static bool usb_build_device_descriptor(const usb_identification_t *identification) {
-    device_descriptor_allocation =
+    device_descriptor =
-        allocate_memory(align32_size(sizeof(device_descriptor_template)),
+        (uint8_t *)port_malloc(sizeof(device_descriptor_template),
-            /*high_address*/ false, /*movable*/ false);
+            /*dma_capable*/ false);
-    uint8_t *device_descriptor = (uint8_t *)device_descriptor_allocation->ptr;
+    if (device_descriptor == NULL) {
+        return false;
+    }
     memcpy(device_descriptor, device_descriptor_template, sizeof(device_descriptor_template));
 
     device_descriptor[DEVICE_VID_LO_INDEX] = identification->vid & 0xFF;
@@ -133,9 +134,11 @@ static void usb_build_device_descriptor(const usb_identification_t *identificati
     usb_add_interface_string(current_interface_string, serial_number_hex_string);
     device_descriptor[DEVICE_SERIAL_NUMBER_STRING_INDEX] = current_interface_string;
     current_interface_string++;
+
+    return true;
 }
 
-static void usb_build_configuration_descriptor(void) {
+static bool usb_build_configuration_descriptor(void) {
     size_t total_descriptor_length = sizeof(configuration_descriptor_template);
 
     // CDC should be first, for compatibility with Adafruit Windows 7 drivers.
@@ -174,11 +177,13 @@ static void usb_build_configuration_descriptor(void) {
     #endif
 
 
-    // Now we now how big the configuration descriptor will be, so we can allocate space for it.
+    // Now we know how big the configuration descriptor will be, so we can allocate space for it.
-    configuration_descriptor_allocation =
+    configuration_descriptor =
-        allocate_memory(align32_size(total_descriptor_length),
+        (uint8_t *)port_malloc(total_descriptor_length,
-            /*high_address*/ false, /*movable*/ false);
+            /*dma_capable*/ false);
-    uint8_t *configuration_descriptor = (uint8_t *)configuration_descriptor_allocation->ptr;
+    if (configuration_descriptor == NULL) {
+        return false;
+    }
 
     // Copy the template, which is the first part of the descriptor, and fix up its length.
 
@@ -260,6 +265,7 @@ static void usb_build_configuration_descriptor(void) {
         descriptor_counts.num_out_endpoints > USB_NUM_OUT_ENDPOINTS) {
         reset_into_safe_mode(SAFE_MODE_USB_TOO_MANY_ENDPOINTS);
     }
+    return true;
 }
 
 // str must not be on the heap.
@@ -277,14 +283,15 @@ static const uint16_t language_id[] = {
     0x0409,
 };
 
-static void usb_build_interface_string_table(void) {
+static bool usb_build_interface_string_table(void) {
     // Allocate space for the le16 String descriptors.
     // Space needed is 2 bytes for String Descriptor header, then 2 bytes for each character
-    string_descriptors_allocation =
+    string_descriptors =
-        allocate_memory(align32_size(current_interface_string * 2 + collected_interface_strings_length * 2),
+        port_malloc(current_interface_string * 2 + collected_interface_strings_length * 2,
-            /*high_address*/ false, /*movable*/ false);
+            /*dma_capable*/ false);
-    uint16_t *string_descriptors = (uint16_t *)string_descriptors_allocation->ptr;
+    if (string_descriptors == NULL) {
-
+        return false;
+    }
 
     uint16_t *string_descriptor = string_descriptors;
 
@@ -312,11 +319,11 @@ static void usb_build_interface_string_table(void) {
         // Move to next descriptor slot.
         string_descriptor += descriptor_size_words;
     }
+    return true;
 }
 
 // After boot.py runs, the USB devices to be used have been chosen, and the descriptors can be set up.
-// This is called after the VM is finished, because it uses storage_allocations.
+bool usb_build_descriptors(const usb_identification_t *identification) {
-void usb_build_descriptors(const usb_identification_t *identification) {
     uint8_t raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH];
     common_hal_mcu_processor_get_uid(raw_id);
 
@@ -333,15 +340,15 @@ void usb_build_descriptors(const usb_identification_t *identification) {
     current_interface_string = 1;
     collected_interface_strings_length = 0;
 
-    usb_build_device_descriptor(identification);
+    return usb_build_device_descriptor(identification) &&
-    usb_build_configuration_descriptor();
+           usb_build_configuration_descriptor() &&
-    usb_build_interface_string_table();
+           usb_build_interface_string_table();
 }
 
 // Invoked when GET DEVICE DESCRIPTOR is received.
 // Application return pointer to descriptor
 uint8_t const *tud_descriptor_device_cb(void) {
-    return (uint8_t *)device_descriptor_allocation->ptr;
+    return device_descriptor;
 }
 
 // Invoked when GET CONFIGURATION DESCRIPTOR is received.
@@ -349,7 +356,7 @@ uint8_t const *tud_descriptor_device_cb(void) {
 // Descriptor contents must exist long enough for transfer to complete
 uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
     (void)index;  // for multiple configurations
-    return (uint8_t *)configuration_descriptor_allocation->ptr;
+    return configuration_descriptor;
 }
 
 // Invoked when GET STRING DESCRIPTOR request is received.

supervisor/stub/stack.c

@@ -35,15 +35,3 @@ void assert_heap_ok(void) {
 
 void stack_init(void) {
 }
-
-void stack_resize(void) {
-}
-
-bool set_next_stack_size(uint32_t size) {
-    (void)size;
-    return true;
-}
-
-uint32_t get_current_stack_size(void) {
-    return 0;
-}

supervisor/supervisor.mk

@@ -1,5 +1,6 @@
 SRC_SUPERVISOR = \
 	main.c \
+	lib/tlsf/tlsf.c \
 	supervisor/port.c \
 	supervisor/shared/background_callback.c \
 	supervisor/shared/board.c \
@@ -7,7 +8,6 @@ SRC_SUPERVISOR = \
 	supervisor/shared/fatfs.c \
 	supervisor/shared/flash.c \
 	supervisor/shared/lock.c \
-	supervisor/shared/memory.c \
 	supervisor/shared/micropython.c \
 	supervisor/shared/port.c \
 	supervisor/shared/reload.c \
@@ -21,6 +21,9 @@ SRC_SUPERVISOR = \
 	supervisor/shared/workflow.c \
 	supervisor/stub/misc.c \
 
+# For tlsf
+CFLAGS += -D_DEBUG=0
+
 NO_USB ?= $(wildcard supervisor/usb.c)
 
 

supervisor/usb.h

@@ -31,8 +31,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "supervisor/memory.h"
-
 // Ports must call this as frequently as they can in order to keep the USB
 // connection alive and responsive.  Normally this is called from background
 // tasks after the USB IRQ handler is executed, but in specific circumstances
@@ -67,12 +65,10 @@ typedef struct {
     char product_name[128];
 } usb_identification_t;
 
-extern supervisor_allocation *usb_identification_allocation;
-
 // Shared implementation.
 bool usb_enabled(void);
 void usb_add_interface_string(uint8_t interface_string_index, const char str[]);
-void usb_build_descriptors(const usb_identification_t *identification);
+bool usb_build_descriptors(const usb_identification_t *identification);
 void usb_disconnect(void);
 void usb_init(void);
 void usb_set_defaults(void);