extmod/modmachine: Provide common bindings for 6 bare-metal functions.

Minor changes for consistency are:
- nrf gains: unique_id(), freq() [they do nothing]
- samd: deepsleep() now resets after calling lightsleep()
- esp32: lightsleep()/deepsleep() no longer take kw arg "sleep", instead
  it's positional to match others.  also, passing 0 here will now do a 0ms
  sleep instead of acting like nothing was passed.
  reset_cause() no longer takes any args (before it would just ignore them)
- mimxrt: freq() with an argument and lightsleep() both raise
  NotImplementedError

Signed-off-by: Damien George <damien@micropython.org>

29 files changed, 316 insertions, 381 deletions

diff --git a/extmod/modmachine.c b/extmod/modmachine.c
index 789d324d6..d56b938bb 100644
--- a/extmod/modmachine.c
+++ b/extmod/modmachine.c
@@ -43,6 +43,16 @@ STATIC void mp_machine_idle(void);
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args);
 #endif
 
+#if MICROPY_PY_MACHINE_BARE_METAL_FUNCS
+STATIC mp_obj_t mp_machine_unique_id(void);
+NORETURN STATIC void mp_machine_reset(void);
+STATIC mp_int_t mp_machine_reset_cause(void);
+STATIC mp_obj_t mp_machine_get_freq(void);
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args);
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args);
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args);
+#endif
+
 // The port can provide additional machine-module implementation in this file.
 #ifdef MICROPY_PY_MACHINE_INCLUDEFILE
 #include MICROPY_PY_MACHINE_INCLUDEFILE
@@ -67,6 +77,46 @@ STATIC mp_obj_t machine_idle(void) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_idle_obj, machine_idle);
 
+#if MICROPY_PY_MACHINE_BARE_METAL_FUNCS
+
+STATIC mp_obj_t machine_unique_id(void) {
+    return mp_machine_unique_id();
+}
+MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
+
+NORETURN STATIC mp_obj_t machine_reset(void) {
+    mp_machine_reset();
+}
+MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
+
+STATIC mp_obj_t machine_reset_cause(void) {
+    return MP_OBJ_NEW_SMALL_INT(mp_machine_reset_cause());
+}
+MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
+
+STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
+    if (n_args == 0) {
+        return mp_machine_get_freq();
+    } else {
+        mp_machine_set_freq(n_args, args);
+        return mp_const_none;
+    }
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);
+
+STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+    mp_machine_lightsleep(n_args, args);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
+
+NORETURN STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+    mp_machine_deepsleep(n_args, args);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
+
+#endif
+
 STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_machine) },
 
@@ -75,14 +125,28 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_mem16), MP_ROM_PTR(&machine_mem16_obj) },
     { MP_ROM_QSTR(MP_QSTR_mem32), MP_ROM_PTR(&machine_mem32_obj) },
 
+    // Miscellaneous functions.
+    #if MICROPY_PY_MACHINE_BARE_METAL_FUNCS
+    { MP_ROM_QSTR(MP_QSTR_unique_id), MP_ROM_PTR(&machine_unique_id_obj) },
+    #endif
+
     // Reset related functions.
     { MP_ROM_QSTR(MP_QSTR_soft_reset), MP_ROM_PTR(&machine_soft_reset_obj) },
     #if MICROPY_PY_MACHINE_BOOTLOADER
     { MP_ROM_QSTR(MP_QSTR_bootloader), MP_ROM_PTR(&machine_bootloader_obj) },
     #endif
+    #if MICROPY_PY_MACHINE_BARE_METAL_FUNCS
+    { MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&machine_reset_obj) },
+    { MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) },
+    #endif
 
     // Power related functions.
     { MP_ROM_QSTR(MP_QSTR_idle), MP_ROM_PTR(&machine_idle_obj) },
+    #if MICROPY_PY_MACHINE_BARE_METAL_FUNCS
+    { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&machine_freq_obj) },
+    { MP_ROM_QSTR(MP_QSTR_lightsleep), MP_ROM_PTR(&machine_lightsleep_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deepsleep), MP_ROM_PTR(&machine_deepsleep_obj) },
+    #endif
 
     // Functions for bit protocols.
     #if MICROPY_PY_MACHINE_BITSTREAM
diff --git a/extmod/modmachine.h b/extmod/modmachine.h
index b0253bbb8..d186ce661 100644
--- a/extmod/modmachine.h
+++ b/extmod/modmachine.h
@@ -241,6 +241,12 @@ NORETURN mp_obj_t machine_bootloader(size_t n_args, const mp_obj_t *args);
 void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len);
 mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us);
 
+MP_DECLARE_CONST_FUN_OBJ_0(machine_unique_id_obj);
+MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_obj);
+MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_cause_obj);
+MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj);
+MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj);
+MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_bootloader_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_bitstream_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj);
diff --git a/ports/cc3200/mods/modmachine.c b/ports/cc3200/mods/modmachine.c
index 1df11c9d2..5eb7e2ef1 100644
--- a/ports/cc3200/mods/modmachine.c
+++ b/ports/cc3200/mods/modmachine.c
@@ -56,16 +56,10 @@
 #endif
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
     MICROPY_PY_MACHINE_INFO_ENTRY \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_main),                MP_ROM_PTR(&machine_main_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_rng),                 MP_ROM_PTR(&machine_rng_get_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep),               MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_wake_reason),         MP_ROM_PTR(&machine_wake_reason_obj) }, \
     \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
@@ -99,24 +93,20 @@ extern OsiTaskHandle    svTaskHandle;
 extern OsiTaskHandle    xSimpleLinkSpawnTaskHndl;
 #endif
 
-
-/// \module machine - functions related to the SoC
-///
-
 MP_DECLARE_CONST_FUN_OBJ_0(machine_disable_irq_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_enable_irq_obj);
 
 /******************************************************************************/
 // MicroPython bindings;
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     // disable wlan
     wlan_stop(SL_STOP_TIMEOUT_LONG);
     // reset the cpu and it's peripherals
     MAP_PRCMMCUReset(true);
-    return mp_const_none;
+    for (;;) {
+    }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 #ifdef DEBUG
 STATIC mp_obj_t machine_info(uint n_args, const mp_obj_t *args) {
@@ -145,17 +135,19 @@ STATIC mp_obj_t machine_info(uint n_args, const mp_obj_t *args) {
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj, 0, 1, machine_info);
 #endif
 
-STATIC mp_obj_t machine_freq(void) {
+STATIC mp_obj_t mp_machine_get_freq(void) {
     return mp_obj_new_int(HAL_FCPU_HZ);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_freq_obj, machine_freq);
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+STATIC mp_obj_t mp_machine_unique_id(void) {
     uint8_t mac[SL_BSSID_LENGTH];
     wlan_get_mac (mac);
     return mp_obj_new_bytes(mac, SL_BSSID_LENGTH);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 STATIC mp_obj_t machine_main(mp_obj_t main) {
     if (mp_obj_is_str(main)) {
@@ -171,22 +163,19 @@ STATIC void mp_machine_idle(void) {
     __WFI();
 }
 
-STATIC mp_obj_t machine_lightsleep(void) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     pyb_sleep_sleep();
-    return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_lightsleep_obj, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep (void) {
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     pyb_sleep_deepsleep();
-    return mp_const_none;
+    for (;;) {
+    }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_deepsleep_obj, machine_deepsleep);
 
-STATIC mp_obj_t machine_reset_cause (void) {
-    return mp_obj_new_int(pyb_sleep_get_reset_cause());
+STATIC mp_int_t mp_machine_reset_cause(void) {
+    return pyb_sleep_get_reset_cause();
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
 STATIC mp_obj_t machine_wake_reason (void) {
     return mp_obj_new_int(pyb_sleep_get_wake_reason());
diff --git a/ports/cc3200/mpconfigport.h b/ports/cc3200/mpconfigport.h
index f2dff028f..7c5273245 100644
--- a/ports/cc3200/mpconfigport.h
+++ b/ports/cc3200/mpconfigport.h
@@ -122,6 +122,7 @@
 #define MICROPY_PY_TIME_INCLUDEFILE                 "ports/cc3200/mods/modtime.c"
 #define MICROPY_PY_MACHINE                          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE              "ports/cc3200/mods/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS         (1)
 #define MICROPY_PY_MACHINE_WDT                      (1)
 #define MICROPY_PY_MACHINE_WDT_INCLUDEFILE          "ports/cc3200/mods/machine_wdt.c"
 
diff --git a/ports/esp32/modmachine.c b/ports/esp32/modmachine.c
index 18bc0965a..0170655ba 100644
--- a/ports/esp32/modmachine.c
+++ b/ports/esp32/modmachine.c
@@ -52,12 +52,7 @@
 #endif
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&machine_freq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id), MP_ROM_PTR(&machine_unique_id_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep), MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep), MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep), MP_ROM_PTR(&machine_deepsleep_obj) }, \
     \
     { MP_ROM_QSTR(MP_QSTR_disable_irq), MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq), MP_ROM_PTR(&machine_enable_irq_obj) }, \
@@ -73,7 +68,6 @@
     { MP_ROM_QSTR(MP_QSTR_DEEPSLEEP), MP_ROM_INT(MACHINE_WAKE_DEEPSLEEP) }, \
     \
     /* Reset reasons */ \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_HARD_RESET), MP_ROM_INT(MP_HARD_RESET) }, \
     { MP_ROM_QSTR(MP_QSTR_PWRON_RESET), MP_ROM_INT(MP_PWRON_RESET) }, \
     { MP_ROM_QSTR(MP_QSTR_WDT_RESET), MP_ROM_INT(MP_WDT_RESET) }, \
@@ -103,65 +97,51 @@ STATIC bool is_soft_reset = 0;
 int esp_clk_cpu_freq(void);
 #endif
 
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        // get
-        return mp_obj_new_int(esp_rom_get_cpu_ticks_per_us() * 1000000);
-    } else {
-        // set
-        mp_int_t freq = mp_obj_get_int(args[0]) / 1000000;
-        if (freq != 20 && freq != 40 && freq != 80 && freq != 160
-            #if !CONFIG_IDF_TARGET_ESP32C3
-            && freq != 240
-            #endif
-            ) {
-            #if CONFIG_IDF_TARGET_ESP32C3
-            mp_raise_ValueError(MP_ERROR_TEXT("frequency must be 20MHz, 40MHz, 80Mhz or 160MHz"));
-            #else
-            mp_raise_ValueError(MP_ERROR_TEXT("frequency must be 20MHz, 40MHz, 80Mhz, 160MHz or 240MHz"));
-            #endif
-        }
-        #if CONFIG_IDF_TARGET_ESP32
-        esp_pm_config_esp32_t pm;
-        #elif CONFIG_IDF_TARGET_ESP32C3
-        esp_pm_config_esp32c3_t pm;
-        #elif CONFIG_IDF_TARGET_ESP32S2
-        esp_pm_config_esp32s2_t pm;
-        #elif CONFIG_IDF_TARGET_ESP32S3
-        esp_pm_config_esp32s3_t pm;
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    return mp_obj_new_int(esp_rom_get_cpu_ticks_per_us() * 1000000);
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_int_t freq = mp_obj_get_int(args[0]) / 1000000;
+    if (freq != 20 && freq != 40 && freq != 80 && freq != 160
+        #if !CONFIG_IDF_TARGET_ESP32C3
+        && freq != 240
+        #endif
+        ) {
+        #if CONFIG_IDF_TARGET_ESP32C3
+        mp_raise_ValueError(MP_ERROR_TEXT("frequency must be 20MHz, 40MHz, 80Mhz or 160MHz"));
+        #else
+        mp_raise_ValueError(MP_ERROR_TEXT("frequency must be 20MHz, 40MHz, 80Mhz, 160MHz or 240MHz"));
         #endif
-        pm.max_freq_mhz = freq;
-        pm.min_freq_mhz = freq;
-        pm.light_sleep_enable = false;
-        esp_err_t ret = esp_pm_configure(&pm);
-        if (ret != ESP_OK) {
-            mp_raise_ValueError(NULL);
-        }
-        while (esp_rom_get_cpu_ticks_per_us() != freq) {
-            vTaskDelay(1);
-        }
-        return mp_const_none;
+    }
+    #if CONFIG_IDF_TARGET_ESP32
+    esp_pm_config_esp32_t pm;
+    #elif CONFIG_IDF_TARGET_ESP32C3
+    esp_pm_config_esp32c3_t pm;
+    #elif CONFIG_IDF_TARGET_ESP32S2
+    esp_pm_config_esp32s2_t pm;
+    #elif CONFIG_IDF_TARGET_ESP32S3
+    esp_pm_config_esp32s3_t pm;
+    #endif
+    pm.max_freq_mhz = freq;
+    pm.min_freq_mhz = freq;
+    pm.light_sleep_enable = false;
+    esp_err_t ret = esp_pm_configure(&pm);
+    if (ret != ESP_OK) {
+        mp_raise_ValueError(NULL);
+    }
+    while (esp_rom_get_cpu_ticks_per_us() != freq) {
+        vTaskDelay(1);
     }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);
-
-STATIC mp_obj_t machine_sleep_helper(wake_type_t wake_type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
-
-    enum {ARG_sleep_ms};
-    const mp_arg_t allowed_args[] = {
-        { MP_QSTR_sleep_ms, MP_ARG_INT, { .u_int = 0 } },
-    };
-
-    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
-    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
-
-
-    mp_int_t expiry = args[ARG_sleep_ms].u_int;
 
+STATIC void machine_sleep_helper(wake_type_t wake_type, size_t n_args, const mp_obj_t *args) {
     // First, disable any previously set wake-up source
     esp_sleep_disable_wakeup_source(ESP_SLEEP_WAKEUP_ALL);
 
-    if (expiry != 0) {
+    // Set the expiry time of the sleep, if given.
+    if (n_args != 0) {
+        mp_int_t expiry = mp_obj_get_int(args[0]);
         esp_sleep_enable_timer_wakeup(((uint64_t)expiry) * 1000);
     }
 
@@ -199,53 +179,45 @@ STATIC mp_obj_t machine_sleep_helper(wake_type_t wake_type, size_t n_args, const
             esp_deep_sleep_start();
             break;
     }
-    return mp_const_none;
 }
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
-    return machine_sleep_helper(MACHINE_WAKE_SLEEP, n_args, pos_args, kw_args);
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+    machine_sleep_helper(MACHINE_WAKE_SLEEP, n_args, args);
 };
-STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_lightsleep_obj, 0, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
-    return machine_sleep_helper(MACHINE_WAKE_DEEPSLEEP, n_args, pos_args, kw_args);
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+    machine_sleep_helper(MACHINE_WAKE_DEEPSLEEP, n_args, args);
+    mp_machine_reset();
 };
-STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_deepsleep_obj, 0,  machine_deepsleep);
 
-STATIC mp_obj_t machine_reset_cause(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+STATIC mp_int_t mp_machine_reset_cause(void) {
     if (is_soft_reset) {
-        return MP_OBJ_NEW_SMALL_INT(MP_SOFT_RESET);
+        return MP_SOFT_RESET;
     }
     switch (esp_reset_reason()) {
         case ESP_RST_POWERON:
         case ESP_RST_BROWNOUT:
-            return MP_OBJ_NEW_SMALL_INT(MP_PWRON_RESET);
-            break;
+            return MP_PWRON_RESET;
 
         case ESP_RST_INT_WDT:
         case ESP_RST_TASK_WDT:
         case ESP_RST_WDT:
-            return MP_OBJ_NEW_SMALL_INT(MP_WDT_RESET);
-            break;
+            return MP_WDT_RESET;
 
         case ESP_RST_DEEPSLEEP:
-            return MP_OBJ_NEW_SMALL_INT(MP_DEEPSLEEP_RESET);
-            break;
+            return MP_DEEPSLEEP_RESET;
 
         case ESP_RST_SW:
         case ESP_RST_PANIC:
         case ESP_RST_EXT: // Comment in ESP-IDF: "For ESP32, ESP_RST_EXT is never returned"
-            return MP_OBJ_NEW_SMALL_INT(MP_HARD_RESET);
-            break;
+            return MP_HARD_RESET;
 
         case ESP_RST_SDIO:
         case ESP_RST_UNKNOWN:
         default:
-            return MP_OBJ_NEW_SMALL_INT(0);
-            break;
+            return 0;
     }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_reset_cause_obj, 0,  machine_reset_cause);
 
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     MICROPY_BOARD_ENTER_BOOTLOADER(n_args, args);
@@ -267,18 +239,15 @@ STATIC mp_obj_t machine_wake_reason(size_t n_args, const mp_obj_t *pos_args, mp_
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_wake_reason_obj, 0,  machine_wake_reason);
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     esp_restart();
-    return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     uint8_t chipid[6];
     esp_efuse_mac_get_default(chipid);
     return mp_obj_new_bytes(chipid, 6);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 STATIC void mp_machine_idle(void) {
     MP_THREAD_GIL_EXIT();
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index ef55d9ae3..083f1d11c 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -97,6 +97,7 @@
 #define MICROPY_PY_OS_URANDOM               (1)
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE      "ports/esp32/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER       (1)
 #define MICROPY_PY_MACHINE_ADC              (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE  "ports/esp32/machine_adc.c"
diff --git a/ports/esp8266/modmachine.c b/ports/esp8266/modmachine.c
index cce6b01ce..d55a656ce 100644
--- a/ports/esp8266/modmachine.c
+++ b/ports/esp8266/modmachine.c
@@ -41,13 +41,7 @@
 #define MACHINE_WAKE_DEEPSLEEP (0x04)
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&machine_freq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id), MP_ROM_PTR(&machine_unique_id_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep), MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep), MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep), MP_ROM_PTR(&machine_deepsleep_obj) }, \
     \
     { MP_ROM_QSTR(MP_QSTR_disable_irq), MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq), MP_ROM_PTR(&machine_enable_irq_obj) }, \
@@ -68,45 +62,42 @@
     { MP_ROM_QSTR(MP_QSTR_WDT_RESET), MP_ROM_INT(REASON_WDT_RST) }, \
     { MP_ROM_QSTR(MP_QSTR_SOFT_RESET), MP_ROM_INT(REASON_SOFT_RESTART) }, \
 
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        // get
-        return mp_obj_new_int(system_get_cpu_freq() * 1000000);
-    } else {
-        // set
-        mp_int_t freq = mp_obj_get_int(args[0]) / 1000000;
-        if (freq != 80 && freq != 160) {
-            mp_raise_ValueError(MP_ERROR_TEXT("frequency can only be either 80Mhz or 160MHz"));
-        }
-        system_update_cpu_freq(freq);
-        return mp_const_none;
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    return mp_obj_new_int(system_get_cpu_freq() * 1000000);
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_int_t freq = mp_obj_get_int(args[0]) / 1000000;
+    if (freq != 80 && freq != 160) {
+        mp_raise_ValueError(MP_ERROR_TEXT("frequency can only be either 80Mhz or 160MHz"));
     }
+    system_update_cpu_freq(freq);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     system_restart();
-    return mp_const_none;
+
+    // we must not return
+    for (;;) {
+        ets_loop_iter();
+    }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
-STATIC mp_obj_t machine_reset_cause(void) {
-    return MP_OBJ_NEW_SMALL_INT(system_get_rst_info()->reason);
+STATIC mp_int_t mp_machine_reset_cause(void) {
+    return system_get_rst_info()->reason;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     uint32_t id = system_get_chip_id();
     return mp_obj_new_bytes((byte *)&id, sizeof(id));
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 STATIC void mp_machine_idle(void) {
     asm ("waiti 0");
     ets_event_poll(); // handle any events after possibly a long wait (eg feed WDT)
 }
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     uint32_t max_us = 0xffffffff;
     if (n_args == 1) {
         mp_int_t max_ms = mp_obj_get_int(args[0]);
@@ -124,11 +115,9 @@ STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
             asm ("waiti 0");
         }
     }
-    return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     // default to sleep forever
     uint32_t sleep_us = 0;
 
@@ -171,10 +160,7 @@ STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
         // we must not return
         ets_loop_iter();
     }
-
-    return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
 
 // These values are from the datasheet
 #define ESP_TIMER_US_MIN (100)
diff --git a/ports/esp8266/mpconfigport.h b/ports/esp8266/mpconfigport.h
index fa9acce6c..1925fc3e7 100644
--- a/ports/esp8266/mpconfigport.h
+++ b/ports/esp8266/mpconfigport.h
@@ -65,6 +65,7 @@
 #define MICROPY_PY_LWIP_SOCK_RAW    (1)
 #define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/esp8266/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_ADC      (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE "ports/esp8266/machine_adc.c"
 #define MICROPY_PY_MACHINE_ADC_READ (1)
diff --git a/ports/mimxrt/modmachine.c b/ports/mimxrt/modmachine.c
index 8bcf10122..b299112d9 100644
--- a/ports/mimxrt/modmachine.c
+++ b/ports/mimxrt/modmachine.c
@@ -57,18 +57,12 @@
 #endif
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
     MICROPY_PY_MACHINE_LED_ENTRY \
     { MP_ROM_QSTR(MP_QSTR_Pin),                 MP_ROM_PTR(&machine_pin_type) }, \
     { MP_ROM_QSTR(MP_QSTR_Timer),               MP_ROM_PTR(&machine_timer_type) }, \
     { MP_ROM_QSTR(MP_QSTR_RTC),                 MP_ROM_PTR(&machine_rtc_type) }, \
     MICROPY_PY_MACHINE_SDCARD_ENTRY \
     \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) }, \
     \
@@ -85,27 +79,27 @@ typedef enum {
     MP_SOFT_RESET
 } reset_reason_t;
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     unsigned char id[8];
     mp_hal_get_unique_id(id);
     return mp_obj_new_bytes(id, sizeof(id));
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     WDOG_TriggerSystemSoftwareReset(WDOG1);
-    return mp_const_none;
+    while (true) {
+        ;
+    }
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
-STATIC mp_obj_t machine_reset_cause(void) {
+STATIC mp_int_t mp_machine_reset_cause(void) {
     #ifdef MIMXRT117x_SERIES
     uint32_t user_reset_flag = kSRC_M7CoreIppUserResetFlag;
     #else
     uint32_t user_reset_flag = kSRC_IppUserResetFlag;
     #endif
     if (SRC->SRSR & user_reset_flag) {
-        return MP_OBJ_NEW_SMALL_INT(MP_DEEPSLEEP_RESET);
+        return MP_DEEPSLEEP_RESET;
     }
     uint16_t reset_cause =
         WDOG_GetStatusFlags(WDOG1) & (kWDOG_PowerOnResetFlag | kWDOG_TimeoutResetFlag | kWDOG_SoftwareResetFlag);
@@ -116,20 +110,26 @@ STATIC mp_obj_t machine_reset_cause(void) {
     } else {
         reset_cause = MP_SOFT_RESET;
     }
-    return MP_OBJ_NEW_SMALL_INT(reset_cause);
+    return reset_cause;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
-STATIC mp_obj_t machine_freq(void) {
+STATIC mp_obj_t mp_machine_get_freq(void) {
     return MP_OBJ_NEW_SMALL_INT(mp_hal_get_cpu_freq());
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_freq_obj, machine_freq);
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_raise_NotImplementedError(NULL);
+}
 
 STATIC void mp_machine_idle(void) {
     MICROPY_EVENT_POLL_HOOK;
 }
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_int_t seconds = mp_obj_get_int(args[0]) / 1000;
         if (seconds > 0) {
@@ -155,10 +155,7 @@ STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     while (true) {
         ;
     }
-
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
 
 STATIC mp_obj_t machine_disable_irq(void) {
     uint32_t state = MICROPY_BEGIN_ATOMIC_SECTION();
diff --git a/ports/mimxrt/mpconfigport.h b/ports/mimxrt/mpconfigport.h
index ad35bfe8c..8150e3b1f 100644
--- a/ports/mimxrt/mpconfigport.h
+++ b/ports/mimxrt/mpconfigport.h
@@ -79,6 +79,7 @@ uint32_t trng_random_u32(void);
 #define MICROPY_PY_RANDOM_SEED_INIT_FUNC    (trng_random_u32())
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE      "ports/mimxrt/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER       (1)
 #define MICROPY_PY_MACHINE_ADC              (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE  "ports/mimxrt/machine_adc.c"
diff --git a/ports/nrf/modules/machine/modmachine.c b/ports/nrf/modules/machine/modmachine.c
index 54e45b4d0..7cdeb78c0 100644
--- a/ports/nrf/modules/machine/modmachine.c
+++ b/ports/nrf/modules/machine/modmachine.c
@@ -85,13 +85,9 @@
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
     { MP_ROM_QSTR(MP_QSTR_info),               MP_ROM_PTR(&machine_info_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset),              MP_ROM_PTR(&machine_reset_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),         MP_ROM_PTR(&machine_enable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),        MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep),              MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),         MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),          MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),        MP_ROM_PTR(&machine_reset_cause_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_Pin),                MP_ROM_PTR(&pin_type) }, \
     \
     MICROPY_PY_MACHINE_RTCOUNTER_ENTRY \
@@ -178,14 +174,16 @@ STATIC mp_obj_t machine_info(mp_uint_t n_args, const mp_obj_t *args) {
 
     return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj, 0, 1, machine_info);
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj, 0, 1, machine_info);
+
+STATIC mp_obj_t mp_machine_unique_id(void) {
+    return mp_const_empty_bytes;
+}
 
 // Resets the board in a manner similar to pushing the external RESET button.
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     NVIC_SystemReset();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     MICROPY_BOARD_ENTER_BOOTLOADER(n_args, args);
@@ -197,22 +195,25 @@ STATIC void mp_machine_idle(void) {
     MICROPY_EVENT_POLL_HOOK;
 }
 
-STATIC mp_obj_t machine_lightsleep(void) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     __WFE();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_lightsleep_obj, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(void) {
-    __WFI();
-    return mp_const_none;
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+    mp_machine_reset();
+}
+
+STATIC mp_int_t mp_machine_reset_cause(void) {
+    return reset_cause;
+}
+
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    mp_raise_NotImplementedError(NULL);
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_deepsleep_obj, machine_deepsleep);
 
-STATIC mp_obj_t machine_reset_cause(void) {
-    return MP_OBJ_NEW_SMALL_INT(reset_cause);
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_raise_NotImplementedError(NULL);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
 STATIC mp_obj_t machine_enable_irq(void) {
 #ifndef BLUETOOTH_SD
diff --git a/ports/nrf/modules/machine/modmachine.h b/ports/nrf/modules/machine/modmachine.h
index 5aab2a602..4574dc001 100644
--- a/ports/nrf/modules/machine/modmachine.h
+++ b/ports/nrf/modules/machine/modmachine.h
@@ -32,9 +32,4 @@
 
 void machine_init(void);
 
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_lightsleep_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_deepsleep_obj);
-
 #endif // __MICROPY_INCLUDED_NRF5_MODMACHINE_H__
diff --git a/ports/nrf/mpconfigport.h b/ports/nrf/mpconfigport.h
index f3e71f675..264b0dfe8 100644
--- a/ports/nrf/mpconfigport.h
+++ b/ports/nrf/mpconfigport.h
@@ -160,6 +160,7 @@
 #define MICROPY_PY_TIME             (1)
 #define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/nrf/modules/machine/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_PULSE    (0)
 #define MICROPY_PY_MACHINE_SOFTI2C  (MICROPY_PY_MACHINE_I2C)
 
diff --git a/ports/renesas-ra/modmachine.c b/ports/renesas-ra/modmachine.c
index b4479e126..5bfbb919f 100644
--- a/ports/renesas-ra/modmachine.c
+++ b/ports/renesas-ra/modmachine.c
@@ -63,13 +63,7 @@
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
     { MP_ROM_QSTR(MP_QSTR_info),                MP_ROM_PTR(&machine_info_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep),               MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) }, \
     \
@@ -183,19 +177,16 @@ STATIC mp_obj_t machine_info(size_t n_args, const mp_obj_t *args) {
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj, 0, 1, machine_info);
 
 // Returns a string of 16 bytes (128 bits), which is the unique ID for the MCU.
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     uint8_t id[16];
     get_unique_id((uint8_t *)&id);
     return mp_obj_new_bytes(id, 16);
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 // Resets the pyboard in a manner similar to pushing the external RESET button.
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     powerctrl_mcu_reset();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 // Activate the bootloader without BOOT* pins.
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
@@ -218,17 +209,13 @@ NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
 }
 
 // get or set the MCU frequencies
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        // get
-        return mp_obj_new_int(SystemCoreClock);
-    } else {
-        // set
-        mp_raise_NotImplementedError(MP_ERROR_TEXT("machine.freq set not supported yet"));
-        return mp_const_none;
-    }
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    return mp_obj_new_int(SystemCoreClock);
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_raise_NotImplementedError(MP_ERROR_TEXT("machine.freq set not supported yet"));
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 4, machine_freq);
 
 // idle()
 // This executies a wfi machine instruction which reduces power consumption
@@ -237,27 +224,22 @@ STATIC void mp_machine_idle(void) {
     __WFI();
 }
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_obj_t args2[2] = {MP_OBJ_NULL, args[0]};
         machine_rtc_wakeup(2, args2);
     }
     powerctrl_enter_stop_mode();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_obj_t args2[2] = {MP_OBJ_NULL, args[0]};
         machine_rtc_wakeup(2, args2);
     }
     powerctrl_enter_standby_mode();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
 
-STATIC mp_obj_t machine_reset_cause(void) {
-    return MP_OBJ_NEW_SMALL_INT(reset_cause);
+STATIC mp_int_t mp_machine_reset_cause(void) {
+    return reset_cause;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
diff --git a/ports/renesas-ra/modmachine.h b/ports/renesas-ra/modmachine.h
index d9e696106..e64b6cc3d 100644
--- a/ports/renesas-ra/modmachine.h
+++ b/ports/renesas-ra/modmachine.h
@@ -33,25 +33,13 @@ extern const mp_obj_type_t machine_touchpad_type;
 extern const mp_obj_type_t machine_dac_type;
 extern const mp_obj_type_t machine_sdcard_type;
 
-
 void machine_init(void);
 void machine_deinit(void);
 void machine_pin_init(void);
 void machine_pin_deinit(void);
 void machine_i2s_init0(void);
 
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_unique_id_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_obj);
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_bootloader_obj);
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj);
-
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj);
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj);
-
 MP_DECLARE_CONST_FUN_OBJ_0(machine_disable_irq_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_enable_irq_obj);
 
-MP_DECLARE_CONST_FUN_OBJ_0(pyb_irq_stats_obj);
-
 #endif // MICROPY_INCLUDED_RENESAS_RA_MODMACHINE_H
diff --git a/ports/renesas-ra/mpconfigport.h b/ports/renesas-ra/mpconfigport.h
index 66655a897..99286fa53 100644
--- a/ports/renesas-ra/mpconfigport.h
+++ b/ports/renesas-ra/mpconfigport.h
@@ -131,6 +131,7 @@
 #ifndef MICROPY_PY_MACHINE
 #define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/renesas-ra/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER (1)
 #define MICROPY_PY_MACHINE_ADC      (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE "ports/renesas-ra/machine_adc.c"
diff --git a/ports/renesas-ra/powerctrl.c b/ports/renesas-ra/powerctrl.c
index 26dc1cbe3..548d31679 100644
--- a/ports/renesas-ra/powerctrl.c
+++ b/ports/renesas-ra/powerctrl.c
@@ -245,7 +245,7 @@ void powerctrl_enter_stop_mode(void) {
     enable_irq(irq_state);
 }
 
-void powerctrl_enter_standby_mode(void) {
+NORETURN void powerctrl_enter_standby_mode(void) {
     rtc_init_finalise();
 
     #if defined(MICROPY_BOARD_ENTER_STANDBY)
@@ -301,4 +301,6 @@ void powerctrl_enter_standby_mode(void) {
     // enter standby mode
 
     // we never return; MCU is reset on exit from standby
+
+    powerctrl_mcu_reset();
 }
diff --git a/ports/renesas-ra/powerctrl.h b/ports/renesas-ra/powerctrl.h
index 1743150b3..34c40ea1a 100644
--- a/ports/renesas-ra/powerctrl.h
+++ b/ports/renesas-ra/powerctrl.h
@@ -37,6 +37,6 @@ NORETURN void powerctrl_enter_bootloader(uint32_t r0, uint32_t bl_addr);
 void powerctrl_check_enter_bootloader(void);
 
 void powerctrl_enter_stop_mode(void);
-void powerctrl_enter_standby_mode(void);
+NORETURN void powerctrl_enter_standby_mode(void);
 
 #endif // MICROPY_INCLUDED_RA_POWERCTRL_H
diff --git a/ports/rp2/modmachine.c b/ports/rp2/modmachine.c
index 8cd9dd462..2e9d1f20c 100644
--- a/ports/rp2/modmachine.c
+++ b/ports/rp2/modmachine.c
@@ -48,14 +48,6 @@
 #define RP2_RESET_WDT (3)
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
-    \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) }, \
     \
@@ -66,32 +58,28 @@
     { MP_ROM_QSTR(MP_QSTR_PWRON_RESET),         MP_ROM_INT(RP2_RESET_PWRON) }, \
     { MP_ROM_QSTR(MP_QSTR_WDT_RESET),           MP_ROM_INT(RP2_RESET_WDT) }, \
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     pico_unique_board_id_t id;
     pico_get_unique_board_id(&id);
     return mp_obj_new_bytes(id.id, sizeof(id.id));
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     watchdog_reboot(0, SRAM_END, 0);
     for (;;) {
         __wfi();
     }
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
-STATIC mp_obj_t machine_reset_cause(void) {
+STATIC mp_int_t mp_machine_reset_cause(void) {
     int reset_cause;
     if (watchdog_caused_reboot()) {
         reset_cause = RP2_RESET_WDT;
     } else {
         reset_cause = RP2_RESET_PWRON;
     }
-    return MP_OBJ_NEW_SMALL_INT(reset_cause);
+    return reset_cause;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     MICROPY_BOARD_ENTER_BOOTLOADER(n_args, args);
@@ -101,28 +89,26 @@ NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     }
 }
 
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        return MP_OBJ_NEW_SMALL_INT(mp_hal_get_cpu_freq());
-    } else {
-        mp_int_t freq = mp_obj_get_int(args[0]);
-        if (!set_sys_clock_khz(freq / 1000, false)) {
-            mp_raise_ValueError(MP_ERROR_TEXT("cannot change frequency"));
-        }
-        #if MICROPY_HW_ENABLE_UART_REPL
-        setup_default_uart();
-        mp_uart_init();
-        #endif
-        return mp_const_none;
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    return MP_OBJ_NEW_SMALL_INT(mp_hal_get_cpu_freq());
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    mp_int_t freq = mp_obj_get_int(args[0]);
+    if (!set_sys_clock_khz(freq / 1000, false)) {
+        mp_raise_ValueError(MP_ERROR_TEXT("cannot change frequency"));
     }
+    #if MICROPY_HW_ENABLE_UART_REPL
+    setup_default_uart();
+    mp_uart_init();
+    #endif
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);
 
 STATIC void mp_machine_idle(void) {
     __wfe();
 }
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     mp_int_t delay_ms = 0;
     bool use_timer_alarm = false;
 
@@ -131,7 +117,7 @@ STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
         if (delay_ms <= 1) {
             // Sleep is too small, just use standard delay.
             mp_hal_delay_ms(delay_ms);
-            return mp_const_none;
+            return;
         }
         use_timer_alarm = delay_ms < (1ULL << 32) / 1000;
         if (use_timer_alarm) {
@@ -148,7 +134,7 @@ STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     #if MICROPY_PY_NETWORK_CYW43
     if (cyw43_has_pending && cyw43_poll != NULL) {
         restore_interrupts(my_interrupts);
-        return mp_const_none;
+        return;
     }
     #endif
     // Disable USB and ADC clocks.
@@ -204,16 +190,12 @@ STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     // Bring back all clocks.
     clocks_init();
     restore_interrupts(my_interrupts);
-
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
-    machine_lightsleep(n_args, args);
-    return machine_reset();
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+    mp_machine_lightsleep(n_args, args);
+    mp_machine_reset();
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
 
 STATIC mp_obj_t machine_disable_irq(void) {
     uint32_t state = MICROPY_BEGIN_ATOMIC_SECTION();
diff --git a/ports/rp2/mpconfigport.h b/ports/rp2/mpconfigport.h
index 8e9d29cf7..ee1f24b87 100644
--- a/ports/rp2/mpconfigport.h
+++ b/ports/rp2/mpconfigport.h
@@ -112,6 +112,7 @@
 #define MICROPY_PY_RANDOM_SEED_INIT_FUNC        (rosc_random_u32())
 #define MICROPY_PY_MACHINE                      (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE          "ports/rp2/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS     (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER           (1)
 #define MICROPY_PY_MACHINE_ADC                  (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE      "ports/rp2/machine_adc.c"
diff --git a/ports/samd/modmachine.c b/ports/samd/modmachine.c
index 3271e160e..9d53048b1 100644
--- a/ports/samd/modmachine.c
+++ b/ports/samd/modmachine.c
@@ -55,19 +55,12 @@
 #endif
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
-    \
     { MP_ROM_QSTR(MP_QSTR_Pin),                 MP_ROM_PTR(&machine_pin_type) }, \
     { MP_ROM_QSTR(MP_QSTR_Timer),               MP_ROM_PTR(&machine_timer_type) }, \
     MICROPY_PY_MACHINE_RTC_ENTRY \
     \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_lightsleep_obj) }, \
     \
     /* Class constants. */ \
     /* Use numerical constants instead of the symbolic names, */ \
@@ -81,15 +74,13 @@
 extern bool EIC_occured;
 extern uint32_t _dbl_tap_addr;
 
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     *DBL_TAP_ADDR = DBL_TAP_MAGIC_RESET;
     #ifdef DBL_TAP_ADDR_ALT
     *DBL_TAP_ADDR_ALT = DBL_TAP_MAGIC_RESET;
     #endif
     NVIC_SystemReset();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     *DBL_TAP_ADDR = DBL_TAP_MAGIC_LOADER;
@@ -99,25 +90,22 @@ NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
     NVIC_SystemReset();
 }
 
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        return MP_OBJ_NEW_SMALL_INT(get_cpu_freq());
-    } else {
-        uint32_t freq = mp_obj_get_int(args[0]);
-        if (freq >= 1000000 && freq <= MAX_CPU_FREQ) {
-            set_cpu_freq(freq);
-        }
-        return mp_const_none;
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    return MP_OBJ_NEW_SMALL_INT(get_cpu_freq());
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    uint32_t freq = mp_obj_get_int(args[0]);
+    if (freq >= 1000000 && freq <= MAX_CPU_FREQ) {
+        set_cpu_freq(freq);
     }
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 1, machine_freq);
 
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     samd_unique_id_t id;
     samd_get_unique_id(&id);
     return mp_obj_new_bytes((byte *)&id.bytes, sizeof(id.bytes));
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 STATIC void mp_machine_idle(void) {
     MICROPY_EVENT_POLL_HOOK;
@@ -136,18 +124,17 @@ STATIC mp_obj_t machine_enable_irq(mp_obj_t state_in) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(machine_enable_irq_obj, machine_enable_irq);
 
-STATIC mp_obj_t machine_reset_cause(void) {
+STATIC mp_int_t mp_machine_reset_cause(void) {
     #if defined(MCU_SAMD21)
-    return MP_OBJ_NEW_SMALL_INT(PM->RCAUSE.reg);
+    return PM->RCAUSE.reg;
     #elif defined(MCU_SAMD51)
-    return MP_OBJ_NEW_SMALL_INT(RSTC->RCAUSE.reg);
+    return RSTC->RCAUSE.reg;
     #else
-    return MP_OBJ_NEW_SMALL_INT(0);
+    return 0;
     #endif
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     int32_t duration = -1;
     uint32_t freq = get_cpu_freq();
     if (n_args > 0) {
@@ -197,6 +184,9 @@ STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     #endif
     // Speed up again
     set_cpu_freq(freq);
-    return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
+
+NORETURN STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+    mp_machine_lightsleep(n_args, args);
+    mp_machine_reset();
+}
diff --git a/ports/samd/mpconfigport.h b/ports/samd/mpconfigport.h
index 90d014e81..1c29b024c 100644
--- a/ports/samd/mpconfigport.h
+++ b/ports/samd/mpconfigport.h
@@ -94,6 +94,7 @@
 #define MICROPY_PY_TIME_INCLUDEFILE         "ports/samd/modtime.c"
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE      "ports/samd/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER       (1)
 #define MICROPY_PY_OS                       (1)
 #define MICROPY_PY_OS_INCLUDEFILE           "ports/samd/modos.c"
diff --git a/ports/stm32/modmachine.c b/ports/stm32/modmachine.c
index 781ceea7d..206d28a89 100644
--- a/ports/stm32/modmachine.c
+++ b/ports/stm32/modmachine.c
@@ -97,14 +97,8 @@
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
     { MP_ROM_QSTR(MP_QSTR_info),                MP_ROM_PTR(&machine_info_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset),               MP_ROM_PTR(&machine_reset_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_freq),                MP_ROM_PTR(&machine_freq_obj) }, \
     MICROPY_PY_MACHINE_RNG_ENTRY \
     { MP_ROM_QSTR(MP_QSTR_sleep),               MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_lightsleep),          MP_ROM_PTR(&machine_lightsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_deepsleep),           MP_ROM_PTR(&machine_deepsleep_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_reset_cause),         MP_ROM_PTR(&machine_reset_cause_obj) }, \
     \
     { MP_ROM_QSTR(MP_QSTR_disable_irq),         MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_enable_irq),          MP_ROM_PTR(&machine_enable_irq_obj) }, \
@@ -283,18 +277,15 @@ STATIC mp_obj_t machine_info(size_t n_args, const mp_obj_t *args) {
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj, 0, 1, machine_info);
 
 // Returns a string of 12 bytes (96 bits), which is the unique ID for the MCU.
-STATIC mp_obj_t machine_unique_id(void) {
+STATIC mp_obj_t mp_machine_unique_id(void) {
     byte *id = (byte *)MP_HAL_UNIQUE_ID_ADDRESS;
     return mp_obj_new_bytes(id, 12);
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_unique_id_obj, machine_unique_id);
 
 // Resets the pyboard in a manner similar to pushing the external RESET button.
-STATIC mp_obj_t machine_reset(void) {
+NORETURN STATIC void mp_machine_reset(void) {
     powerctrl_mcu_reset();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 // Activate the bootloader without BOOT* pins.
 NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
@@ -323,57 +314,53 @@ NORETURN void mp_machine_bootloader(size_t n_args, const mp_obj_t *args) {
 }
 
 // get or set the MCU frequencies
-STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        // get
-        mp_obj_t tuple[] = {
-            mp_obj_new_int(HAL_RCC_GetSysClockFreq()),
-            mp_obj_new_int(HAL_RCC_GetHCLKFreq()),
-            mp_obj_new_int(HAL_RCC_GetPCLK1Freq()),
-            #if !defined(STM32F0) && !defined(STM32G0)
-            mp_obj_new_int(HAL_RCC_GetPCLK2Freq()),
-            #endif
-        };
-        return mp_obj_new_tuple(MP_ARRAY_SIZE(tuple), tuple);
-    } else {
-        // set
-        #if defined(STM32F0) || defined(STM32L0) || defined(STM32L1) || defined(STM32L4) || defined(STM32G0)
-        mp_raise_NotImplementedError(MP_ERROR_TEXT("machine.freq set not supported yet"));
-        #else
-        mp_int_t sysclk = mp_obj_get_int(args[0]);
-        mp_int_t ahb = sysclk;
-        #if defined(STM32H7)
-        if (ahb > 200000000) {
-            ahb /= 2;
-        }
-        #endif
-        #if defined(STM32WB)
-        mp_int_t apb1 = ahb;
-        mp_int_t apb2 = ahb;
-        #else
-        mp_int_t apb1 = ahb / 4;
-        mp_int_t apb2 = ahb / 2;
+STATIC mp_obj_t mp_machine_get_freq(void) {
+    mp_obj_t tuple[] = {
+        mp_obj_new_int(HAL_RCC_GetSysClockFreq()),
+        mp_obj_new_int(HAL_RCC_GetHCLKFreq()),
+        mp_obj_new_int(HAL_RCC_GetPCLK1Freq()),
+        #if !defined(STM32F0) && !defined(STM32G0)
+        mp_obj_new_int(HAL_RCC_GetPCLK2Freq()),
         #endif
-        if (n_args > 1) {
-            ahb = mp_obj_get_int(args[1]);
-            if (n_args > 2) {
-                apb1 = mp_obj_get_int(args[2]);
-                if (n_args > 3) {
-                    apb2 = mp_obj_get_int(args[3]);
-                }
+    };
+    return mp_obj_new_tuple(MP_ARRAY_SIZE(tuple), tuple);
+}
+
+STATIC void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
+    #if defined(STM32F0) || defined(STM32L0) || defined(STM32L1) || defined(STM32L4) || defined(STM32G0)
+    mp_raise_NotImplementedError(MP_ERROR_TEXT("machine.freq set not supported yet"));
+    #else
+    mp_int_t sysclk = mp_obj_get_int(args[0]);
+    mp_int_t ahb = sysclk;
+    #if defined(STM32H7)
+    if (ahb > 200000000) {
+        ahb /= 2;
+    }
+    #endif
+    #if defined(STM32WB)
+    mp_int_t apb1 = ahb;
+    mp_int_t apb2 = ahb;
+    #else
+    mp_int_t apb1 = ahb / 4;
+    mp_int_t apb2 = ahb / 2;
+    #endif
+    if (n_args > 1) {
+        ahb = mp_obj_get_int(args[1]);
+        if (n_args > 2) {
+            apb1 = mp_obj_get_int(args[2]);
+            if (n_args > 3) {
+                apb2 = mp_obj_get_int(args[3]);
             }
         }
-        int ret = powerctrl_set_sysclk(sysclk, ahb, apb1, apb2);
-        if (ret == -MP_EINVAL) {
-            mp_raise_ValueError(MP_ERROR_TEXT("invalid freq"));
-        } else if (ret < 0) {
-            MICROPY_BOARD_FATAL_ERROR("can't change freq");
-        }
-        return mp_const_none;
-        #endif
     }
+    int ret = powerctrl_set_sysclk(sysclk, ahb, apb1, apb2);
+    if (ret == -MP_EINVAL) {
+        mp_raise_ValueError(MP_ERROR_TEXT("invalid freq"));
+    } else if (ret < 0) {
+        MICROPY_BOARD_FATAL_ERROR("can't change freq");
+    }
+    #endif
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj, 0, 4, machine_freq);
 
 // idle()
 // This executies a wfi machine instruction which reduces power consumption
@@ -382,27 +369,22 @@ STATIC void mp_machine_idle(void) {
     __WFI();
 }
 
-STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_obj_t args2[2] = {MP_OBJ_NULL, args[0]};
         pyb_rtc_wakeup(2, args2);
     }
     powerctrl_enter_stop_mode();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
 
-STATIC mp_obj_t machine_deepsleep(size_t n_args, const mp_obj_t *args) {
+STATIC void mp_machine_deepsleep(size_t n_args, const mp_obj_t *args) {
     if (n_args != 0) {
         mp_obj_t args2[2] = {MP_OBJ_NULL, args[0]};
         pyb_rtc_wakeup(2, args2);
     }
     powerctrl_enter_standby_mode();
-    return mp_const_none;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj, 0, 1, machine_deepsleep);
 
-STATIC mp_obj_t machine_reset_cause(void) {
-    return MP_OBJ_NEW_SMALL_INT(reset_cause);
+STATIC mp_int_t mp_machine_reset_cause(void) {
+    return reset_cause;
 }
-MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
diff --git a/ports/stm32/modmachine.h b/ports/stm32/modmachine.h
index 8c9e1241b..899a29be8 100644
--- a/ports/stm32/modmachine.h
+++ b/ports/stm32/modmachine.h
@@ -33,13 +33,6 @@ void machine_deinit(void);
 void machine_i2s_init0();
 
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_info_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_unique_id_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_obj);
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_freq_obj);
-
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj);
-MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_deepsleep_obj);
-MP_DECLARE_CONST_FUN_OBJ_0(machine_reset_cause_obj);
 
 MP_DECLARE_CONST_FUN_OBJ_0(machine_disable_irq_obj);
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(machine_enable_irq_obj);
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index db48c8c3b..e11e72103 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -111,6 +111,7 @@
 #ifndef MICROPY_PY_MACHINE
 #define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/stm32/modmachine.c"
+#define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER (1)
 #define MICROPY_PY_MACHINE_ADC      (1)
 #define MICROPY_PY_MACHINE_ADC_INCLUDEFILE "ports/stm32/machine_adc.c"
diff --git a/ports/stm32/powerctrl.c b/ports/stm32/powerctrl.c
index 1bb66c978..712021edb 100644
--- a/ports/stm32/powerctrl.c
+++ b/ports/stm32/powerctrl.c
@@ -993,7 +993,7 @@ void powerctrl_enter_stop_mode(void) {
     enable_irq(irq_state);
 }
 
-void powerctrl_enter_standby_mode(void) {
+NORETURN void powerctrl_enter_standby_mode(void) {
     rtc_init_finalise();
 
     #if defined(MICROPY_BOARD_ENTER_STANDBY)
@@ -1114,5 +1114,7 @@ void powerctrl_enter_standby_mode(void) {
 
     // enter standby mode
     HAL_PWR_EnterSTANDBYMode();
-    // we never return; MCU is reset on exit from standby
+
+    // MCU is reset on exit from standby, but just in case it's not, do an explicit reset.
+    powerctrl_mcu_reset();
 }
diff --git a/ports/stm32/powerctrl.h b/ports/stm32/powerctrl.h
index e9adc5296..5b9240561 100644
--- a/ports/stm32/powerctrl.h
+++ b/ports/stm32/powerctrl.h
@@ -47,6 +47,6 @@ void powerctrl_config_systick(void);
 int powerctrl_rcc_clock_config_pll(RCC_ClkInitTypeDef *rcc_init, uint32_t sysclk_mhz, bool need_pllsai);
 int powerctrl_set_sysclk(uint32_t sysclk, uint32_t ahb, uint32_t apb1, uint32_t apb2);
 void powerctrl_enter_stop_mode(void);
-void powerctrl_enter_standby_mode(void);
+NORETURN void powerctrl_enter_standby_mode(void);
 
 #endif // MICROPY_INCLUDED_STM32_POWERCTRL_H
diff --git a/ports/zephyr/modmachine.c b/ports/zephyr/modmachine.c
index 16109a3af..701598978 100644
--- a/ports/zephyr/modmachine.c
+++ b/ports/zephyr/modmachine.c
@@ -50,13 +50,13 @@ STATIC mp_obj_t machine_reset(void) {
     // Won't get here, Zephyr has infiniloop on its side
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
+MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_obj, machine_reset);
 
 STATIC mp_obj_t machine_reset_cause(void) {
     printf("Warning: %s is not implemented\n", __func__);
     return MP_OBJ_NEW_SMALL_INT(42);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
+MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
 
 STATIC void mp_machine_idle(void) {
     k_yield();
diff --git a/ports/zephyr/modmachine.h b/ports/zephyr/modmachine.h
index e3a69d8c1..19dbe6a16 100644
--- a/ports/zephyr/modmachine.h
+++ b/ports/zephyr/modmachine.h
@@ -3,8 +3,6 @@
 
 #include "py/obj.h"
 
-MP_DECLARE_CONST_FUN_OBJ_0(machine_info_obj);
-
 typedef struct _machine_pin_obj_t {
     mp_obj_base_t base;
     const struct device *port;