diff --git a/devices/ble_hci/common-hal/_bleio/CharacteristicBuffer.c b/devices/ble_hci/common-hal/_bleio/CharacteristicBuffer.c
index bb6b8788b6..0d87f03ae3 100644
--- a/devices/ble_hci/common-hal/_bleio/CharacteristicBuffer.c
+++ b/devices/ble_hci/common-hal/_bleio/CharacteristicBuffer.c
@@ -33,6 +33,7 @@
 
 #include "shared-bindings/_bleio/__init__.h"
 #include "shared-bindings/_bleio/Connection.h"
+#include "shared-bindings/_bleio/CharacteristicBuffer.h"
 #include "supervisor/shared/tick.h"
 #include "common-hal/_bleio/CharacteristicBuffer.h"
 
diff --git a/devices/ble_hci/common-hal/_bleio/Connection.h b/devices/ble_hci/common-hal/_bleio/Connection.h
index 2933bb87a5..185a8b3517 100644
--- a/devices/ble_hci/common-hal/_bleio/Connection.h
+++ b/devices/ble_hci/common-hal/_bleio/Connection.h
@@ -85,5 +85,6 @@ typedef struct {
 uint16_t bleio_connection_get_conn_handle(bleio_connection_obj_t *self);
 mp_obj_t bleio_connection_new_from_internal(bleio_connection_internal_t *connection);
 bleio_connection_internal_t *bleio_conn_handle_to_connection(uint16_t conn_handle);
+void bleio_connection_clear(bleio_connection_internal_t *self);
 
 #endif // MICROPY_INCLUDED_BLE_HCI_COMMON_HAL_CONNECTION_H
diff --git a/devices/ble_hci/common-hal/_bleio/att.c b/devices/ble_hci/common-hal/_bleio/att.c
index b0fc884e00..ff3294a865 100644
--- a/devices/ble_hci/common-hal/_bleio/att.c
+++ b/devices/ble_hci/common-hal/_bleio/att.c
@@ -857,20 +857,6 @@ STATIC void process_find_info_req(uint16_t conn_handle, uint16_t mtu, uint8_t dl
     }
 }
 
-int att_find_info_req(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle, uint8_t response_buffer[]) {
-    struct __packed req {
-        struct bt_att_hdr h;
-        struct bt_att_find_info_req r;
-    } req = { {
-                  .code = BT_ATT_OP_FIND_INFO_REQ,
-              }, {
-                  .start_handle = start_handle,
-                  .end_handle = end_handle,
-              }};
-
-    return send_req_wait_for_rsp(conn_handle, sizeof(req), (uint8_t *)&req, response_buffer);
-}
-
 STATIC void process_find_info_rsp(uint16_t conn_handle, uint8_t dlen, uint8_t data[]) {
     if (dlen < 2) {
         return; // invalid, drop
@@ -925,7 +911,7 @@ STATIC void process_find_type_req(uint16_t conn_handle, uint16_t mtu, uint8_t dl
     }
 }
 
-void process_read_group_req(uint16_t conn_handle, uint16_t mtu, uint8_t dlen, uint8_t data[]) {
+STATIC void process_read_group_req(uint16_t conn_handle, uint16_t mtu, uint8_t dlen, uint8_t data[]) {
     struct bt_att_read_group_req *req = (struct bt_att_read_group_req *)data;
     uint16_t type_uuid = req->uuid[0] | (req->uuid[1] << 8);
 
@@ -1009,25 +995,6 @@ void process_read_group_req(uint16_t conn_handle, uint16_t mtu, uint8_t dlen, ui
     }
 }
 
-int att_read_group_req(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle, uint16_t uuid, uint8_t response_buffer[]) {
-
-    typedef struct __packed {
-        struct bt_att_hdr h;
-        struct bt_att_read_group_req r;
-    } req_t;
-
-    uint8_t req_bytes[sizeof(req_t) + sizeof(uuid)];
-    req_t *req = (req_t *)req_bytes;
-
-    req->h.code = BT_ATT_OP_READ_GROUP_REQ;
-    req->r.start_handle = start_handle;
-    req->r.end_handle = end_handle;
-    req->r.uuid[0] = uuid & 0xff;
-    req->r.uuid[1] = uuid >> 8;
-
-    return send_req_wait_for_rsp(conn_handle, sizeof(req_bytes), req_bytes, response_buffer);
-}
-
 STATIC void process_read_group_rsp(uint16_t conn_handle, uint8_t dlen, uint8_t data[]) {
     if (dlen < 2) {
         return; // invalid, drop
@@ -1305,24 +1272,6 @@ STATIC void process_read_type_req(uint16_t conn_handle, uint16_t mtu, uint8_t dl
     }
 }
 
-int att_read_type_req(uint16_t conn_handle, uint16_t start_handle, uint16_t end_handle, uint16_t type, uint8_t response_buffer[]) {
-    typedef struct __packed {
-        struct bt_att_hdr h;
-        struct bt_att_read_type_req r;
-    } req_t;
-
-    uint8_t req_bytes[sizeof(req_t) + sizeof(type)];
-    req_t *req = (req_t *)req_bytes;
-
-    req->h.code = BT_ATT_OP_READ_TYPE_REQ;
-    req->r.start_handle = start_handle;
-    req->r.end_handle = end_handle;
-    req->r.uuid[0] = type & 0xff;
-    req->r.uuid[1] = type >> 8;
-
-    return send_req_wait_for_rsp(conn_handle, sizeof(req_bytes), req_bytes, response_buffer);
-}
-
 STATIC void process_read_type_rsp(uint16_t conn_handle, uint8_t dlen, uint8_t data[]) {
     if (dlen < 1) {
         return; // invalid, drop
@@ -1713,77 +1662,3 @@ void att_process_data(uint16_t conn_handle, uint8_t dlen, uint8_t data[]) {
             break;
     }
 }
-
-// FIX Do we need all of these?
-void check_att_err(uint8_t err) {
-    const compressed_string_t *msg = NULL;
-    switch (err) {
-        case 0:
-            return;
-        case BT_ATT_ERR_INVALID_HANDLE:
-            msg = translate("Invalid handle");
-            break;
-        case BT_ATT_ERR_READ_NOT_PERMITTED:
-            msg = translate("Read not permitted");
-            break;
-        case BT_ATT_ERR_WRITE_NOT_PERMITTED:
-            msg = translate("Write not permitted");
-            break;
-        case BT_ATT_ERR_INVALID_PDU:
-            msg = translate("Invalid PDU");
-            break;
-        case BT_ATT_ERR_NOT_SUPPORTED:
-            msg = translate("Not supported");
-            break;
-        case BT_ATT_ERR_INVALID_OFFSET:
-            msg = translate("Invalid offset");
-            break;
-        case BT_ATT_ERR_PREPARE_QUEUE_FULL:
-            msg = translate("Prepare queue full");
-            break;
-        case BT_ATT_ERR_ATTRIBUTE_NOT_FOUND:
-            msg = translate("Attribute not found");
-            break;
-        case BT_ATT_ERR_ATTRIBUTE_NOT_LONG:
-            msg = translate("Attribute not long");
-            break;
-        case BT_ATT_ERR_ENCRYPTION_KEY_SIZE:
-            msg = translate("Encryption key size");
-            break;
-        case BT_ATT_ERR_INVALID_ATTRIBUTE_LEN:
-            msg = translate("Invalid attribute length");
-            break;
-        case BT_ATT_ERR_UNLIKELY:
-            msg = translate("Unlikely");
-            break;
-        case BT_ATT_ERR_UNSUPPORTED_GROUP_TYPE:
-            msg = translate("Unsupported group type");
-            break;
-        case BT_ATT_ERR_INSUFFICIENT_RESOURCES:
-            msg = translate("Insufficient resources");
-            break;
-        case BT_ATT_ERR_DB_OUT_OF_SYNC:
-            msg = translate("DB out of sync");
-            break;
-        case BT_ATT_ERR_VALUE_NOT_ALLOWED:
-            msg = translate("Value not allowed");
-            break;
-    }
-    if (msg) {
-        mp_raise_bleio_BluetoothError(msg);
-    }
-
-    switch (err) {
-        case BT_ATT_ERR_AUTHENTICATION:
-            msg = translate("Insufficient authentication");
-            break;
-        case BT_ATT_ERR_INSUFFICIENT_ENCRYPTION:
-            msg = translate("Insufficient encryption");
-            break;
-    }
-    if (msg) {
-        mp_raise_bleio_SecurityError(msg);
-    }
-
-    mp_raise_bleio_BluetoothError(translate("Unknown ATT error: 0x%02x"), err);
-}
diff --git a/ports/atmel-samd/Makefile b/ports/atmel-samd/Makefile
index 721cfd4f0a..045f3741eb 100644
--- a/ports/atmel-samd/Makefile
+++ b/ports/atmel-samd/Makefile
@@ -291,7 +291,7 @@ $(BUILD)/asf4/$(CHIP_FAMILY)/hpl/sdhc/hpl_sdhc.o: CFLAGS += -Wno-cast-align -Wno
 endif
 
 SRC_ASF := $(addprefix asf4/$(CHIP_FAMILY)/, $(SRC_ASF))
-$(patsubst $(SRC_ASF),%.c,%.o): CFLAGS += -Wno-missing-prototypes
+$(patsubst %.c,$(BUILD)/%.o,$(SRC_ASF)): CFLAGS += -Wno-missing-prototypes
 
 SRC_PERIPHERALS := \
 	peripherals/samd/$(PERIPHERALS_CHIP_FAMILY)/adc.c \
@@ -310,7 +310,7 @@ SRC_PERIPHERALS := \
 	peripherals/samd/sercom.c \
 	peripherals/samd/timers.c \
 
-$(patsubst $(SRC_PERIPHERALS),%.c,%.o): CFLAGS += -Wno-missing-prototypes
+$(patsubst %.c,$(BUILD)/%.o,$(SRC_PERIPHERALS)): CFLAGS += -Wno-missing-prototypes
 
 SRC_C += \
 	audio_dma.c \
diff --git a/ports/atmel-samd/common-hal/audiobusio/PDMIn.c b/ports/atmel-samd/common-hal/audiobusio/PDMIn.c
index e00d69c848..e6363395a6 100644
--- a/ports/atmel-samd/common-hal/audiobusio/PDMIn.c
+++ b/ports/atmel-samd/common-hal/audiobusio/PDMIn.c
@@ -485,6 +485,3 @@ uint32_t common_hal_audiobusio_pdmin_record_to_buffer(audiobusio_pdmin_obj_t* se
 
     return values_output;
 }
-
-void common_hal_audiobusio_pdmin_record_to_file(audiobusio_pdmin_obj_t* self, uint8_t* buffer, uint32_t length) {
-}
diff --git a/ports/atmel-samd/common-hal/busio/__init__.c b/ports/atmel-samd/common-hal/busio/__init__.c
index 8ec549e931..8d1f085ffa 100644
--- a/ports/atmel-samd/common-hal/busio/__init__.c
+++ b/ports/atmel-samd/common-hal/busio/__init__.c
@@ -25,6 +25,7 @@
  */
 
 #include "samd/sercom.h"
+#include "common-hal/busio/__init__.h"
 
 static bool never_reset_sercoms[SERCOM_INST_NUM];
 
diff --git a/ports/atmel-samd/common-hal/countio/Counter.c b/ports/atmel-samd/common-hal/countio/Counter.c
index 4531a4ed8c..e4df55eba6 100644
--- a/ports/atmel-samd/common-hal/countio/Counter.c
+++ b/ports/atmel-samd/common-hal/countio/Counter.c
@@ -1,5 +1,6 @@
 
 #include "common-hal/countio/Counter.h"
+#include "shared-bindings/countio/Counter.h"
 
 #include "atmel_start_pins.h"
 
diff --git a/ports/atmel-samd/common-hal/microcontroller/Processor.c b/ports/atmel-samd/common-hal/microcontroller/Processor.c
index e9831c953a..29d6612ad8 100644
--- a/ports/atmel-samd/common-hal/microcontroller/Processor.c
+++ b/ports/atmel-samd/common-hal/microcontroller/Processor.c
@@ -65,6 +65,7 @@
 
 #include "py/mphal.h"
 #include "common-hal/microcontroller/Processor.h"
+#include "shared-bindings/microcontroller/Processor.h"
 #include "shared-bindings/microcontroller/ResetReason.h"
 
 #include "samd/adc.h"
diff --git a/ports/atmel-samd/common-hal/nvm/ByteArray.c b/ports/atmel-samd/common-hal/nvm/ByteArray.c
index 9d711d3413..e6f77bb048 100644
--- a/ports/atmel-samd/common-hal/nvm/ByteArray.c
+++ b/ports/atmel-samd/common-hal/nvm/ByteArray.c
@@ -25,6 +25,7 @@
  */
 
 #include "common-hal/nvm/ByteArray.h"
+#include "shared-bindings/nvm/ByteArray.h"
 
 #include "hal_flash.h"
 
@@ -33,11 +34,11 @@
 #include <stdint.h>
 #include <string.h>
 
-uint32_t common_hal_nvm_bytearray_get_length(nvm_bytearray_obj_t *self) {
+uint32_t common_hal_nvm_bytearray_get_length(const nvm_bytearray_obj_t *self) {
     return self->len;
 }
 
-bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t *self,
+bool common_hal_nvm_bytearray_set_bytes(const nvm_bytearray_obj_t *self,
     uint32_t start_index, uint8_t *values, uint32_t len) {
     // We don't use features that use any advanced NVMCTRL features so we can fake the descriptor
     // whenever we need it instead of storing it long term.
@@ -49,7 +50,7 @@ bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t *self,
 }
 
 // NVM memory is memory mapped so reading it is easy.
-void common_hal_nvm_bytearray_get_bytes(nvm_bytearray_obj_t *self,
+void common_hal_nvm_bytearray_get_bytes(const nvm_bytearray_obj_t *self,
     uint32_t start_index, uint32_t len, uint8_t *values) {
     memcpy(values, self->start_address + start_index, len);
 }
diff --git a/ports/atmel-samd/common-hal/os/__init__.c b/ports/atmel-samd/common-hal/os/__init__.c
index 6c554bff30..f0e20bdfcf 100644
--- a/ports/atmel-samd/common-hal/os/__init__.c
+++ b/ports/atmel-samd/common-hal/os/__init__.c
@@ -30,6 +30,8 @@
 #include "py/objtuple.h"
 #include "py/qstr.h"
 
+#include "shared-bindings/os/__init__.h"
+
 #ifdef SAM_D5X_E5X
 #include "hal/include/hal_rand_sync.h"
 #endif
@@ -66,7 +68,7 @@ mp_obj_t common_hal_os_uname(void) {
     return (mp_obj_t)&os_uname_info_obj;
 }
 
-bool common_hal_os_urandom(uint8_t *buffer, uint32_t length) {
+bool common_hal_os_urandom(uint8_t *buffer, mp_uint_t length) {
     #ifdef SAM_D5X_E5X
     hri_mclk_set_APBCMASK_TRNG_bit(MCLK);
     struct rand_sync_desc random;
diff --git a/ports/atmel-samd/common-hal/ps2io/Ps2.c b/ports/atmel-samd/common-hal/ps2io/Ps2.c
index f07cadf417..6e2fb58e51 100644
--- a/ports/atmel-samd/common-hal/ps2io/Ps2.c
+++ b/ports/atmel-samd/common-hal/ps2io/Ps2.c
@@ -26,6 +26,7 @@
  */
 
 #include "common-hal/ps2io/Ps2.h"
+#include "shared-bindings/ps2io/Ps2.h"
 
 #include <stdint.h>
 
@@ -302,11 +303,6 @@ uint16_t common_hal_ps2io_ps2_get_len(ps2io_ps2_obj_t *self) {
     return self->bufcount;
 }
 
-bool common_hal_ps2io_ps2_get_paused(ps2io_ps2_obj_t *self) {
-    uint32_t mask = 1 << self->channel;
-    return (EIC->INTENSET.reg & (mask << EIC_INTENSET_EXTINT_Pos)) == 0;
-}
-
 int16_t common_hal_ps2io_ps2_popleft(ps2io_ps2_obj_t *self) {
     common_hal_mcu_disable_interrupts();
     if (self->bufcount <= 0) {
diff --git a/ports/atmel-samd/common-hal/pulseio/PulseOut.c b/ports/atmel-samd/common-hal/pulseio/PulseOut.c
index b72e0d1f43..b0407a1136 100644
--- a/ports/atmel-samd/common-hal/pulseio/PulseOut.c
+++ b/ports/atmel-samd/common-hal/pulseio/PulseOut.c
@@ -59,7 +59,7 @@ static void turn_off(__IO PORT_PINCFG_Type *pincfg) {
     pincfg->reg = PORT_PINCFG_RESETVALUE;
 }
 
-void pulse_finish(void) {
+STATIC void pulse_finish(void) {
     pulse_index++;
 
     if (active_pincfg == NULL) {
diff --git a/ports/atmel-samd/common-hal/pwmio/PWMOut.c b/ports/atmel-samd/common-hal/pwmio/PWMOut.c
index fa6a2d3f47..eaec10463d 100644
--- a/ports/atmel-samd/common-hal/pwmio/PWMOut.c
+++ b/ports/atmel-samd/common-hal/pwmio/PWMOut.c
@@ -91,7 +91,7 @@ static uint8_t tcc_channel(const pin_timer_t *t) {
     return t->wave_output % tcc_cc_num[t->index];
 }
 
-bool channel_ok(const pin_timer_t *t) {
+STATIC bool channel_ok(const pin_timer_t *t) {
     uint8_t channel_bit = 1 << tcc_channel(t);
     return (!t->is_tc && ((tcc_channels[t->index] & channel_bit) == 0)) ||
            t->is_tc;
diff --git a/ports/atmel-samd/common-hal/rotaryio/IncrementalEncoder.c b/ports/atmel-samd/common-hal/rotaryio/IncrementalEncoder.c
index dc9cf65334..856fe04dbc 100644
--- a/ports/atmel-samd/common-hal/rotaryio/IncrementalEncoder.c
+++ b/ports/atmel-samd/common-hal/rotaryio/IncrementalEncoder.c
@@ -25,6 +25,7 @@
  */
 
 #include "common-hal/rotaryio/IncrementalEncoder.h"
+#include "shared-bindings/rotaryio/IncrementalEncoder.h"
 #include "shared-module/rotaryio/IncrementalEncoder.h"
 
 #include "atmel_start_pins.h"
diff --git a/ports/atmel-samd/common-hal/rtc/RTC.c b/ports/atmel-samd/common-hal/rtc/RTC.c
index 65d7d94220..e2a67bd174 100644
--- a/ports/atmel-samd/common-hal/rtc/RTC.c
+++ b/ports/atmel-samd/common-hal/rtc/RTC.c
@@ -35,6 +35,7 @@
 #include "py/runtime.h"
 #include "shared/timeutils/timeutils.h"
 #include "shared-bindings/rtc/__init__.h"
+#include "shared-bindings/rtc/RTC.h"
 #include "supervisor/port.h"
 #include "supervisor/shared/translate.h"
 
diff --git a/ports/atmel-samd/common-hal/watchdog/WatchDogTimer.c b/ports/atmel-samd/common-hal/watchdog/WatchDogTimer.c
index 329242887c..2091b7d302 100644
--- a/ports/atmel-samd/common-hal/watchdog/WatchDogTimer.c
+++ b/ports/atmel-samd/common-hal/watchdog/WatchDogTimer.c
@@ -50,7 +50,7 @@ mp_float_t common_hal_watchdog_get_timeout(watchdog_watchdogtimer_obj_t *self) {
     return self->timeout;
 }
 
-void setup_wdt(watchdog_watchdogtimer_obj_t *self, int setting) {
+STATIC void setup_wdt(watchdog_watchdogtimer_obj_t *self, int setting) {
     OSC32KCTRL->OSCULP32K.bit.EN1K = 1;  // Enable out 1K (for WDT)
 
     // disable watchdog for config
diff --git a/ports/raspberrypi/Makefile b/ports/raspberrypi/Makefile
index 2739bf6547..28e28d6269 100644
--- a/ports/raspberrypi/Makefile
+++ b/ports/raspberrypi/Makefile
@@ -132,7 +132,7 @@ endif
 # Remove -Wno-stringop-overflow after we can test with CI's GCC 10. Mac's looks weird.
 DISABLE_WARNINGS = -Wno-stringop-overflow -Wno-unused-function -Wno-unused-variable -Wno-strict-overflow -Wno-cast-align -Wno-strict-prototypes -Wno-nested-externs -Wno-double-promotion -Wno-sign-compare
 
-CFLAGS += $(INC) -Wall -Werror -std=gnu11 -nostdlib -fshort-enums $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS)
+CFLAGS += $(INC) -Wall -Werror -std=gnu11 -nostdlib -fshort-enums $(BASE_CFLAGS) $(CFLAGS_MOD) $(COPT) $(DISABLE_WARNINGS) -Werror=missing-prototypes
 
 CFLAGS += \
   -march=armv6-m \
diff --git a/ports/raspberrypi/bindings/rp2pio/StateMachine.c b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
index 39b975ff8d..61e526b226 100644
--- a/ports/raspberrypi/bindings/rp2pio/StateMachine.c
+++ b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
@@ -617,7 +617,7 @@ const mp_obj_type_t rp2pio_statemachine_type = {
     .locals_dict = (mp_obj_dict_t *)&rp2pio_statemachine_locals_dict,
 };
 
-rp2pio_statemachine_obj_t *validate_obj_is_statemachine(mp_obj_t obj) {
+static rp2pio_statemachine_obj_t *validate_obj_is_statemachine(mp_obj_t obj) {
     if (!mp_obj_is_type(obj, &rp2pio_statemachine_type)) {
         mp_raise_TypeError_varg(translate("Expected a %q"), rp2pio_statemachine_type.name);
     }
diff --git a/ports/raspberrypi/boards/adafruit_macropad_rp2040/board.c b/ports/raspberrypi/boards/adafruit_macropad_rp2040/board.c
index 1e16629f30..2d452244f7 100644
--- a/ports/raspberrypi/boards/adafruit_macropad_rp2040/board.c
+++ b/ports/raspberrypi/boards/adafruit_macropad_rp2040/board.c
@@ -31,6 +31,7 @@
 #include "shared-bindings/busio/SPI.h"
 #include "shared-bindings/microcontroller/Pin.h"
 #include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
+#include "supervisor/board.h"
 #include "supervisor/shared/board.h"
 
 displayio_fourwire_obj_t board_display_obj;
diff --git a/ports/raspberrypi/common-hal/alarm/SleepMemory.c b/ports/raspberrypi/common-hal/alarm/SleepMemory.c
index b8fcdfbccf..c1765296dc 100644
--- a/ports/raspberrypi/common-hal/alarm/SleepMemory.c
+++ b/ports/raspberrypi/common-hal/alarm/SleepMemory.c
@@ -28,6 +28,7 @@
 
 #include "py/runtime.h"
 #include "common-hal/alarm/SleepMemory.h"
+#include "shared-bindings/alarm/SleepMemory.h"
 
 void alarm_sleep_memory_reset(void) {
 }
diff --git a/ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c b/ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c
index 276e2e409a..53cbfca57b 100644
--- a/ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c
+++ b/ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c
@@ -42,7 +42,7 @@ STATIC bool _pinalarm_set = false;
 
 #define GPIO_IRQ_ALL_EVENTS 0x15u
 
-void gpio_callback(uint gpio, uint32_t events) {
+STATIC void gpio_callback(uint gpio, uint32_t events) {
     alarm_triggered_pins |= (1 << gpio);
     woke_up = true;
 
diff --git a/ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c b/ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c
index 65c2b680d8..16ac8fc31e 100644
--- a/ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c
+++ b/ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c
@@ -37,7 +37,7 @@
 STATIC bool woke_up = false;
 STATIC bool _timealarm_set = false;
 
-void timer_callback(void) {
+STATIC void timer_callback(void) {
     woke_up = true;
 }
 
diff --git a/ports/raspberrypi/common-hal/analogio/AnalogIn.c b/ports/raspberrypi/common-hal/analogio/AnalogIn.c
index 7db2956b03..1d77630063 100644
--- a/ports/raspberrypi/common-hal/analogio/AnalogIn.c
+++ b/ports/raspberrypi/common-hal/analogio/AnalogIn.c
@@ -25,6 +25,7 @@
  */
 
 #include "common-hal/analogio/AnalogIn.h"
+#include "shared-bindings/analogio/AnalogIn.h"
 #include "py/runtime.h"
 #include "supervisor/shared/translate.h"
 
diff --git a/ports/raspberrypi/common-hal/audiobusio/PDMIn.c b/ports/raspberrypi/common-hal/audiobusio/PDMIn.c
index 323a3dfbc8..f2775c2543 100644
--- a/ports/raspberrypi/common-hal/audiobusio/PDMIn.c
+++ b/ports/raspberrypi/common-hal/audiobusio/PDMIn.c
@@ -171,7 +171,3 @@ uint32_t common_hal_audiobusio_pdmin_record_to_buffer(audiobusio_pdmin_obj_t *se
 
     return output_count;
 }
-
-void common_hal_audiobusio_pdmin_record_to_file(audiobusio_pdmin_obj_t *self, uint8_t *buffer, uint32_t length) {
-
-}
diff --git a/ports/raspberrypi/common-hal/countio/Counter.c b/ports/raspberrypi/common-hal/countio/Counter.c
index 3d2d291b99..bbf71f996e 100644
--- a/ports/raspberrypi/common-hal/countio/Counter.c
+++ b/ports/raspberrypi/common-hal/countio/Counter.c
@@ -95,7 +95,7 @@ void common_hal_countio_counter_reset(countio_counter_obj_t *self) {
     self->count = 0;
 }
 
-void counter_interrupt_handler() {
+void counter_interrupt_handler(void) {
     uint32_t mask = pwm_get_irq_status_mask();
 
     uint8_t i = 1, pos = 1;
diff --git a/ports/raspberrypi/common-hal/countio/Counter.h b/ports/raspberrypi/common-hal/countio/Counter.h
index 78e00e0dd2..7469dd2d00 100644
--- a/ports/raspberrypi/common-hal/countio/Counter.h
+++ b/ports/raspberrypi/common-hal/countio/Counter.h
@@ -14,7 +14,7 @@ typedef struct {
 } countio_counter_obj_t;
 
 
-void counter_interrupt_handler();
+void counter_interrupt_handler(void);
 
 void reset_countio(void);
 
diff --git a/ports/raspberrypi/common-hal/imagecapture/ParallelImageCapture.c b/ports/raspberrypi/common-hal/imagecapture/ParallelImageCapture.c
index 280c87e234..9eabc9f967 100644
--- a/ports/raspberrypi/common-hal/imagecapture/ParallelImageCapture.c
+++ b/ports/raspberrypi/common-hal/imagecapture/ParallelImageCapture.c
@@ -68,7 +68,7 @@
         /* .wrap */ \
     }
 
-mcu_pin_obj_t *pin_from_number(uint8_t number) {
+STATIC mcu_pin_obj_t *pin_from_number(uint8_t number) {
     const mp_map_t *mcu_map = &mcu_pin_globals.map;
     for (uint8_t i = 0; i < mcu_map->alloc; i++) {
         mp_obj_t val = mcu_map->table[i].value;
diff --git a/ports/raspberrypi/common-hal/microcontroller/Processor.c b/ports/raspberrypi/common-hal/microcontroller/Processor.c
index 68518d75b3..8c5bc7ba75 100644
--- a/ports/raspberrypi/common-hal/microcontroller/Processor.c
+++ b/ports/raspberrypi/common-hal/microcontroller/Processor.c
@@ -29,6 +29,7 @@
 
 #include "py/mphal.h"
 #include "common-hal/microcontroller/Processor.h"
+#include "shared-bindings/microcontroller/Processor.h"
 #include "shared-bindings/microcontroller/ResetReason.h"
 
 #include "src/rp2_common/hardware_adc/include/hardware/adc.h"
diff --git a/ports/raspberrypi/common-hal/nvm/ByteArray.c b/ports/raspberrypi/common-hal/nvm/ByteArray.c
index 94d98d686f..6908cbeabf 100644
--- a/ports/raspberrypi/common-hal/nvm/ByteArray.c
+++ b/ports/raspberrypi/common-hal/nvm/ByteArray.c
@@ -25,6 +25,7 @@
  */
 
 #include "common-hal/nvm/ByteArray.h"
+#include "shared-bindings/nvm/ByteArray.h"
 
 #include <string.h>
 
@@ -36,7 +37,7 @@ static const uint32_t flash_binary_start = (uint32_t)&__flash_binary_start;
 
 #define RMV_OFFSET(addr) addr - flash_binary_start
 
-uint32_t common_hal_nvm_bytearray_get_length(nvm_bytearray_obj_t *self) {
+uint32_t common_hal_nvm_bytearray_get_length(const nvm_bytearray_obj_t *self) {
     return self->len;
 }
 
@@ -63,12 +64,12 @@ static void erase_and_write_sector(uint32_t address, uint32_t len, uint8_t *byte
     flash_range_program(RMV_OFFSET(CIRCUITPY_INTERNAL_NVM_START_ADDR), buffer, FLASH_SECTOR_SIZE);
 }
 
-void common_hal_nvm_bytearray_get_bytes(nvm_bytearray_obj_t *self,
+void common_hal_nvm_bytearray_get_bytes(const nvm_bytearray_obj_t *self,
     uint32_t start_index, uint32_t len, uint8_t *values) {
     memcpy(values, self->start_address + start_index, len);
 }
 
-bool common_hal_nvm_bytearray_set_bytes(nvm_bytearray_obj_t *self,
+bool common_hal_nvm_bytearray_set_bytes(const nvm_bytearray_obj_t *self,
     uint32_t start_index, uint8_t *values, uint32_t len) {
     uint8_t values_in[len];
     common_hal_nvm_bytearray_get_bytes(self, start_index, len, values_in);
diff --git a/ports/raspberrypi/common-hal/os/__init__.c b/ports/raspberrypi/common-hal/os/__init__.c
index 25fe317abe..805418288a 100644
--- a/ports/raspberrypi/common-hal/os/__init__.c
+++ b/ports/raspberrypi/common-hal/os/__init__.c
@@ -30,6 +30,8 @@
 #include "py/objtuple.h"
 #include "py/qstr.h"
 
+#include "shared-bindings/os/__init__.h"
+
 #include "lib/crypto-algorithms/sha256.h"
 
 #include "hardware/structs/rosc.h"
@@ -104,7 +106,7 @@ static void get_random_bits(BYTE out[SHA256_BLOCK_SIZE]) {
     sha256_final(&context, out);
 }
 
-bool common_hal_os_urandom(uint8_t *buffer, uint32_t length) {
+bool common_hal_os_urandom(uint8_t *buffer, mp_uint_t length) {
 #define ROSC_POWER_SAVE (1) // assume ROSC is not necessarily active all the time
     #if ROSC_POWER_SAVE
     uint32_t old_rosc_ctrl = rosc_hw->ctrl;
diff --git a/ports/raspberrypi/common-hal/pulseio/PulseIn.c b/ports/raspberrypi/common-hal/pulseio/PulseIn.c
index 53dfa008b8..9d3f614987 100644
--- a/ports/raspberrypi/common-hal/pulseio/PulseIn.c
+++ b/ports/raspberrypi/common-hal/pulseio/PulseIn.c
@@ -121,7 +121,8 @@ void common_hal_pulseio_pulsein_pause(pulseio_pulsein_obj_t *self) {
     self->level_count = 0;
     self->buf_index = 0;
 }
-void common_hal_pulseio_pulsein_interrupt(pulseio_pulsein_obj_t *self) {
+void common_hal_pulseio_pulsein_interrupt(void *self_in) {
+    pulseio_pulsein_obj_t *self = self_in;
 
     uint32_t rxfifo = 0;
 
diff --git a/ports/raspberrypi/common-hal/pulseio/PulseIn.h b/ports/raspberrypi/common-hal/pulseio/PulseIn.h
index 5386220911..f2c4fc0d06 100644
--- a/ports/raspberrypi/common-hal/pulseio/PulseIn.h
+++ b/ports/raspberrypi/common-hal/pulseio/PulseIn.h
@@ -48,6 +48,6 @@ typedef struct {
 } pulseio_pulsein_obj_t;
 
 void pulsein_reset(void);
-void common_hal_pulseio_pulsein_interrupt();
+void common_hal_pulseio_pulsein_interrupt(void *);
 
 #endif // MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_PULSEIO_PULSEIN_H
diff --git a/ports/raspberrypi/common-hal/pulseio/PulseOut.c b/ports/raspberrypi/common-hal/pulseio/PulseOut.c
index 2b4ab7185c..7704fdff6f 100644
--- a/ports/raspberrypi/common-hal/pulseio/PulseOut.c
+++ b/ports/raspberrypi/common-hal/pulseio/PulseOut.c
@@ -41,7 +41,7 @@
 
 volatile alarm_id_t cur_alarm = 0;
 
-void pulse_finish(pulseio_pulseout_obj_t *self) {
+static void pulse_finish(pulseio_pulseout_obj_t *self) {
     self->pulse_index++;
     // Turn pwm pin off by switching the GPIO mux to SIO (the cpu manual
     // control).
diff --git a/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c b/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c
index 649c9421e0..1105d357c5 100644
--- a/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c
+++ b/ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c
@@ -28,6 +28,7 @@
 
 #include <hardware/regs/pio.h>
 #include "common-hal/rotaryio/IncrementalEncoder.h"
+#include "shared-bindings/rotaryio/IncrementalEncoder.h"
 #include "shared-module/rotaryio/IncrementalEncoder.h"
 #include "bindings/rp2pio/__init__.h"
 #include "bindings/rp2pio/StateMachine.h"
diff --git a/ports/raspberrypi/common-hal/rp2pio/StateMachine.c b/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
index 27672f0de0..4479006d4e 100644
--- a/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
+++ b/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
@@ -70,7 +70,7 @@ static void rp2pio_statemachine_set_pull(uint32_t pull_pin_up, uint32_t pull_pin
     }
 }
 
-void _reset_statemachine(PIO pio, uint8_t sm, bool leave_pins) {
+STATIC void _reset_statemachine(PIO pio, uint8_t sm, bool leave_pins) {
     uint8_t pio_index = pio_get_index(pio);
     uint32_t program_id = _current_program_id[pio_index][sm];
     if (program_id == 0) {
@@ -587,7 +587,7 @@ bool common_hal_rp2pio_statemachine_deinited(rp2pio_statemachine_obj_t *self) {
     return self->state_machine == NUM_PIO_STATE_MACHINES;
 }
 
-enum dma_channel_transfer_size _stride_to_dma_size(uint8_t stride) {
+STATIC enum dma_channel_transfer_size _stride_to_dma_size(uint8_t stride) {
     switch (stride) {
         case 4:
             return DMA_SIZE_32;
diff --git a/ports/raspberrypi/common-hal/rtc/RTC.c b/ports/raspberrypi/common-hal/rtc/RTC.c
index 8647fc246c..9bd10abf70 100644
--- a/ports/raspberrypi/common-hal/rtc/RTC.c
+++ b/ports/raspberrypi/common-hal/rtc/RTC.c
@@ -24,6 +24,7 @@
  * THE SOFTWARE.
  */
 #include "shared-bindings/rtc/RTC.h"
+#include "common-hal/rtc/RTC.h"
 
 #include <sys/time.h>
 
diff --git a/ports/raspberrypi/supervisor/internal_flash.c b/ports/raspberrypi/supervisor/internal_flash.c
index fa18f24fe0..c128cb74b2 100644
--- a/ports/raspberrypi/supervisor/internal_flash.c
+++ b/ports/raspberrypi/supervisor/internal_flash.c
@@ -39,6 +39,7 @@
 #include "lib/oofatfs/ff.h"
 #include "shared-bindings/microcontroller/__init__.h"
 
+#include "supervisor/flash.h"
 #include "supervisor/usb.h"
 
 #include "src/rp2040/hardware_structs/include/hardware/structs/sio.h"
diff --git a/ports/raspberrypi/supervisor/port.c b/ports/raspberrypi/supervisor/port.c
index fca6d6554c..5041250c0a 100644
--- a/ports/raspberrypi/supervisor/port.c
+++ b/ports/raspberrypi/supervisor/port.c
@@ -248,6 +248,7 @@ void port_idle_until_interrupt(void) {
 /**
  * \brief Default interrupt handler for unused IRQs.
  */
+extern void HardFault_Handler(void); // provide a prototype to avoid a missing-prototypes diagnostic
 __attribute__((used)) void HardFault_Handler(void) {
     #ifdef ENABLE_MICRO_TRACE_BUFFER
     // Turn off the micro trace buffer so we don't fill it up in the infinite
diff --git a/py/circuitpy_defns.mk b/py/circuitpy_defns.mk
index c258317d18..d4980d78fe 100644
--- a/py/circuitpy_defns.mk
+++ b/py/circuitpy_defns.mk
@@ -635,7 +635,7 @@ ifeq ($(CIRCUITPY_RGBMATRIX),1)
 SRC_MOD += $(addprefix lib/protomatter/src/, \
 	core.c \
 )
-$(BUILD)/lib/protomatter/src/core.o: CFLAGS += -include "shared-module/rgbmatrix/allocator.h" -DCIRCUITPY -Wno-missing-braces
+$(BUILD)/lib/protomatter/src/core.o: CFLAGS += -include "shared-module/rgbmatrix/allocator.h" -DCIRCUITPY -Wno-missing-braces -Wno-missing-prototypes
 endif
 
 # All possible sources are listed here, and are filtered by SRC_PATTERNS.
@@ -685,6 +685,7 @@ $(addprefix lib/,\
 	libm/wf_tgamma.c \
 	)
 endif
+$(patsubst %.c,$(BUILD)/%.o,$(SRC_LIBM)): CFLAGS += -Wno-missing-prototypes
 endif
 
 SRC_CIRCUITPY_COMMON = \
diff --git a/shared-bindings/_bleio/CharacteristicBuffer.h b/shared-bindings/_bleio/CharacteristicBuffer.h
index 1fd9dd838c..de85f019bc 100644
--- a/shared-bindings/_bleio/CharacteristicBuffer.h
+++ b/shared-bindings/_bleio/CharacteristicBuffer.h
@@ -44,7 +44,7 @@ uint32_t common_hal_bleio_characteristic_buffer_read(bleio_characteristic_buffer
 uint32_t common_hal_bleio_characteristic_buffer_rx_characters_available(bleio_characteristic_buffer_obj_t *self);
 void common_hal_bleio_characteristic_buffer_clear_rx_buffer(bleio_characteristic_buffer_obj_t *self);
 bool common_hal_bleio_characteristic_buffer_deinited(bleio_characteristic_buffer_obj_t *self);
-int common_hal_bleio_characteristic_buffer_deinit(bleio_characteristic_buffer_obj_t *self);
+void common_hal_bleio_characteristic_buffer_deinit(bleio_characteristic_buffer_obj_t *self);
 bool common_hal_bleio_characteristic_buffer_connected(bleio_characteristic_buffer_obj_t *self);
 
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTICBUFFER_H
diff --git a/shared-bindings/_bleio/ScanEntry.h b/shared-bindings/_bleio/ScanEntry.h
index 35473fd50e..b376433027 100644
--- a/shared-bindings/_bleio/ScanEntry.h
+++ b/shared-bindings/_bleio/ScanEntry.h
@@ -39,6 +39,6 @@ mp_obj_t common_hal_bleio_scanentry_get_advertisement_bytes(bleio_scanentry_obj_
 mp_int_t common_hal_bleio_scanentry_get_rssi(bleio_scanentry_obj_t *self);
 bool common_hal_bleio_scanentry_get_connectable(bleio_scanentry_obj_t *self);
 bool common_hal_bleio_scanentry_get_scan_response(bleio_scanentry_obj_t *self);
-bool common_hal_bleio_scanentry_matches(bleio_scanentry_obj_t *self, uint8_t *prefixes, size_t prefixes_len, bool match_all);
+bool common_hal_bleio_scanentry_matches(bleio_scanentry_obj_t *self, const uint8_t *prefixes, size_t prefixes_len, bool match_all);
 
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_SCANENTRY_H
diff --git a/shared-bindings/_eve/__init__.h b/shared-bindings/_eve/__init__.h
index 883b1a15bf..96a10f010b 100644
--- a/shared-bindings/_eve/__init__.h
+++ b/shared-bindings/_eve/__init__.h
@@ -27,6 +27,8 @@
 #ifndef MICROPY_INCLUDED_SHARED_BINDINGS__EVE___INIT___H
 #define MICROPY_INCLUDED_SHARED_BINDINGS__EVE___INIT___H
 
+#include "shared-module/_eve/__init__.h"
+
 void common_hal__eve_flush(common_hal__eve_t *eve);
 void common_hal__eve_add(common_hal__eve_t *eve, size_t len, void *buf);
 void common_hal__eve_Vertex2f(common_hal__eve_t *eve, mp_float_t x, mp_float_t y);
diff --git a/shared-bindings/alarm/__init__.c b/shared-bindings/alarm/__init__.c
index 5d3c1a15f0..4160f6a334 100644
--- a/shared-bindings/alarm/__init__.c
+++ b/shared-bindings/alarm/__init__.c
@@ -70,7 +70,7 @@
 
 // wake_alarm is implemented as a dictionary entry, so there's no code here.
 
-void validate_objs_are_alarms(size_t n_args, const mp_obj_t *objs) {
+STATIC void validate_objs_are_alarms(size_t n_args, const mp_obj_t *objs) {
     for (size_t i = 0; i < n_args; i++) {
         if (mp_obj_is_type(objs[i], &alarm_pin_pinalarm_type) ||
             mp_obj_is_type(objs[i], &alarm_time_timealarm_type) ||
diff --git a/shared-bindings/alarm/time/TimeAlarm.c b/shared-bindings/alarm/time/TimeAlarm.c
index 2fdd6218bb..bd7502e891 100644
--- a/shared-bindings/alarm/time/TimeAlarm.c
+++ b/shared-bindings/alarm/time/TimeAlarm.c
@@ -29,8 +29,9 @@
 #include "py/objproperty.h"
 #include "py/runtime.h"
 
-#include "shared-bindings/time/__init__.h"
 #include "shared-bindings/alarm/time/TimeAlarm.h"
+#include "shared-bindings/rtc/__init__.h"
+#include "shared-bindings/time/__init__.h"
 
 #include "supervisor/shared/translate.h"
 
diff --git a/shared-bindings/board/__init__.h b/shared-bindings/board/__init__.h
index 837608fa9e..bc4d7df61f 100644
--- a/shared-bindings/board/__init__.h
+++ b/shared-bindings/board/__init__.h
@@ -47,6 +47,10 @@ mp_obj_t common_hal_board_get_uart(void);
 mp_obj_t common_hal_board_create_uart(void);
 MP_DECLARE_CONST_FUN_OBJ_0(board_uart_obj);
 
+mp_obj_t board_i2c(void);
+mp_obj_t board_spi(void);
+mp_obj_t board_uart(void);
+
 #define CIRCUITPYTHON_BOARD_DICT_STANDARD_ITEMS \
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_board) }, \
     { MP_ROM_QSTR(MP_QSTR_board_id), MP_ROM_PTR(&board_module_id_obj) },
diff --git a/shared-bindings/busio/UART.c b/shared-bindings/busio/UART.c
index a46ab6826e..90cd7c3aa6 100644
--- a/shared-bindings/busio/UART.c
+++ b/shared-bindings/busio/UART.c
@@ -152,7 +152,7 @@ STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, si
 #if CIRCUITPY_BUSIO_UART
 
 // Helper to ensure we have the native super class instead of a subclass.
-busio_uart_obj_t *native_uart(mp_obj_t uart_obj) {
+STATIC busio_uart_obj_t *native_uart(mp_obj_t uart_obj) {
     mp_obj_t native_uart = mp_obj_cast_to_native_base(uart_obj, &busio_uart_type);
     if (native_uart == MP_OBJ_NULL) {
         mp_raise_ValueError_varg(translate("Must be a %q subclass."), MP_QSTR_UART);
diff --git a/shared-bindings/os/__init__.c b/shared-bindings/os/__init__.c
index fc246582fd..02efd41988 100644
--- a/shared-bindings/os/__init__.c
+++ b/shared-bindings/os/__init__.c
@@ -68,7 +68,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_0(os_uname_obj, os_uname);
 //|     """Change current directory."""
 //|     ...
 //|
-mp_obj_t os_chdir(mp_obj_t path_in) {
+STATIC mp_obj_t os_chdir(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     common_hal_os_chdir(path);
     return mp_const_none;
@@ -79,7 +79,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(os_chdir_obj, os_chdir);
 //|     """Get the current directory."""
 //|     ...
 //|
-mp_obj_t os_getcwd(void) {
+STATIC mp_obj_t os_getcwd(void) {
     return common_hal_os_getcwd();
 }
 MP_DEFINE_CONST_FUN_OBJ_0(os_getcwd_obj, os_getcwd);
@@ -88,7 +88,7 @@ MP_DEFINE_CONST_FUN_OBJ_0(os_getcwd_obj, os_getcwd);
 //|     """With no argument, list the current directory.  Otherwise list the given directory."""
 //|     ...
 //|
-mp_obj_t os_listdir(size_t n_args, const mp_obj_t *args) {
+STATIC mp_obj_t os_listdir(size_t n_args, const mp_obj_t *args) {
     const char *path;
     if (n_args == 1) {
         path = mp_obj_str_get_str(args[0]);
@@ -103,7 +103,7 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(os_listdir_obj, 0, 1, os_listdir);
 //|     """Create a new directory."""
 //|     ...
 //|
-mp_obj_t os_mkdir(mp_obj_t path_in) {
+STATIC mp_obj_t os_mkdir(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     common_hal_os_mkdir(path);
     return mp_const_none;
@@ -114,7 +114,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(os_mkdir_obj, os_mkdir);
 //|     """Remove a file."""
 //|     ...
 //|
-mp_obj_t os_remove(mp_obj_t path_in) {
+STATIC mp_obj_t os_remove(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     common_hal_os_remove(path);
     return mp_const_none;
@@ -125,7 +125,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(os_remove_obj, os_remove);
 //|     """Remove a directory."""
 //|     ...
 //|
-mp_obj_t os_rename(mp_obj_t old_path_in, mp_obj_t new_path_in) {
+STATIC mp_obj_t os_rename(mp_obj_t old_path_in, mp_obj_t new_path_in) {
     const char *old_path = mp_obj_str_get_str(old_path_in);
     const char *new_path = mp_obj_str_get_str(new_path_in);
     common_hal_os_rename(old_path, new_path);
@@ -137,7 +137,7 @@ MP_DEFINE_CONST_FUN_OBJ_2(os_rename_obj, os_rename);
 //|     """Rename a file."""
 //|     ...
 //|
-mp_obj_t os_rmdir(mp_obj_t path_in) {
+STATIC mp_obj_t os_rmdir(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     common_hal_os_rmdir(path);
     return mp_const_none;
@@ -153,7 +153,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(os_rmdir_obj, os_rmdir);
 //|        which is the number of seconds corresponding to 1999-12-31."""
 //|     ...
 //|
-mp_obj_t os_stat(mp_obj_t path_in) {
+STATIC mp_obj_t os_stat(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     return common_hal_os_stat(path);
 }
@@ -180,7 +180,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(os_stat_obj, os_stat);
 //|     in a port-specific implementation."""
 //|     ...
 //|
-mp_obj_t os_statvfs(mp_obj_t path_in) {
+STATIC mp_obj_t os_statvfs(mp_obj_t path_in) {
     const char *path = mp_obj_str_get_str(path_in);
     return common_hal_os_statvfs(path);
 }
diff --git a/shared-bindings/sdcardio/SDCard.c b/shared-bindings/sdcardio/SDCard.c
index 14cf5f5b0d..757a1b8532 100644
--- a/shared-bindings/sdcardio/SDCard.c
+++ b/shared-bindings/sdcardio/SDCard.c
@@ -106,7 +106,7 @@ STATIC mp_obj_t sdcardio_sdcard_make_new(const mp_obj_type_t *type, size_t n_arg
 //|
 //|         :return: The number of 512-byte blocks, as a number"""
 //|
-mp_obj_t sdcardio_sdcard_count(mp_obj_t self_in) {
+STATIC mp_obj_t sdcardio_sdcard_count(mp_obj_t self_in) {
     sdcardio_sdcard_obj_t *self = (sdcardio_sdcard_obj_t *)self_in;
     return mp_obj_new_int_from_ull(common_hal_sdcardio_sdcard_get_blockcount(self));
 }
@@ -117,7 +117,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(sdcardio_sdcard_count_obj, sdcardio_sdcard_count);
 //|
 //|         :return: None"""
 //|
-mp_obj_t sdcardio_sdcard_deinit(mp_obj_t self_in) {
+STATIC mp_obj_t sdcardio_sdcard_deinit(mp_obj_t self_in) {
     sdcardio_sdcard_obj_t *self = (sdcardio_sdcard_obj_t *)self_in;
     common_hal_sdcardio_sdcard_deinit(self);
     return mp_const_none;
@@ -135,7 +135,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(sdcardio_sdcard_deinit_obj, sdcardio_sdcard_deinit);
 //|         :return: None"""
 //|
 
-mp_obj_t sdcardio_sdcard_readblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
+STATIC mp_obj_t sdcardio_sdcard_readblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
     uint32_t start_block = mp_obj_get_int(start_block_in);
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_WRITE);
@@ -154,7 +154,7 @@ MP_DEFINE_CONST_FUN_OBJ_3(sdcardio_sdcard_readblocks_obj, sdcardio_sdcard_readbl
 //|
 //|         :return: None"""
 //|         ...
-mp_obj_t sdcardio_sdcard_sync(mp_obj_t self_in) {
+STATIC mp_obj_t sdcardio_sdcard_sync(mp_obj_t self_in) {
     sdcardio_sdcard_obj_t *self = (sdcardio_sdcard_obj_t *)self_in;
     int result = common_hal_sdcardio_sdcard_sync(self);
     if (result < 0) {
@@ -176,7 +176,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(sdcardio_sdcard_sync_obj, sdcardio_sdcard_sync);
 //|         :return: None"""
 //|
 
-mp_obj_t sdcardio_sdcard_writeblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
+STATIC mp_obj_t sdcardio_sdcard_writeblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
     uint32_t start_block = mp_obj_get_int(start_block_in);
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ);
diff --git a/shared-bindings/sdioio/SDCard.c b/shared-bindings/sdioio/SDCard.c
index e03d180d7a..ba45af4576 100644
--- a/shared-bindings/sdioio/SDCard.c
+++ b/shared-bindings/sdioio/SDCard.c
@@ -168,7 +168,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(sdioio_sdcard_count_obj, sdioio_sdcard_count);
 //|         :param ~_typing.WriteableBuffer buf: The buffer to write into.  Length must be multiple of 512.
 //|
 //|         :return: None"""
-mp_obj_t sdioio_sdcard_readblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
+STATIC mp_obj_t sdioio_sdcard_readblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
     uint32_t start_block = mp_obj_get_int(start_block_in);
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_WRITE);
@@ -191,7 +191,7 @@ MP_DEFINE_CONST_FUN_OBJ_3(sdioio_sdcard_readblocks_obj, sdioio_sdcard_readblocks
 //|
 //|         :return: None"""
 //|
-mp_obj_t sdioio_sdcard_writeblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
+STATIC mp_obj_t sdioio_sdcard_writeblocks(mp_obj_t self_in, mp_obj_t start_block_in, mp_obj_t buf_in) {
     uint32_t start_block = mp_obj_get_int(start_block_in);
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ);
diff --git a/shared-bindings/storage/__init__.c b/shared-bindings/storage/__init__.c
index c5769b56b5..3c957468da 100644
--- a/shared-bindings/storage/__init__.c
+++ b/shared-bindings/storage/__init__.c
@@ -54,7 +54,7 @@
 //|     """
 //|     ...
 //|
-mp_obj_t storage_mount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+STATIC mp_obj_t storage_mount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_filesystem, ARG_mount_path, ARG_readonly };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_filesystem, MP_ARG_OBJ | MP_ARG_REQUIRED },
@@ -91,7 +91,7 @@ MP_DEFINE_CONST_FUN_OBJ_KW(storage_mount_obj, 0, storage_mount);
 //|     This is the CircuitPython analog to the UNIX ``umount`` command."""
 //|     ...
 //|
-mp_obj_t storage_umount(mp_obj_t mnt_in) {
+STATIC mp_obj_t storage_umount(mp_obj_t mnt_in) {
     if (mp_obj_is_str(mnt_in)) {
         common_hal_storage_umount_path(mp_obj_str_get_str(mnt_in));
     } else {
@@ -113,7 +113,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(storage_umount_obj, storage_umount);
 //|         filesystem will be corrupted."""
 //|     ...
 //|
-mp_obj_t storage_remount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+STATIC mp_obj_t storage_remount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_mount_path, ARG_readonly, ARG_disable_concurrent_write_protection };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_mount_path, MP_ARG_OBJ | MP_ARG_REQUIRED },
@@ -136,7 +136,7 @@ MP_DEFINE_CONST_FUN_OBJ_KW(storage_remount_obj, 0, storage_remount);
 //|     """Retrieves the mount object associated with the mount path"""
 //|     ...
 //|
-mp_obj_t storage_getmount(const mp_obj_t mnt_in) {
+STATIC mp_obj_t storage_getmount(const mp_obj_t mnt_in) {
     return common_hal_storage_getmount(mp_obj_str_get_str(mnt_in));
 }
 MP_DEFINE_CONST_FUN_OBJ_1(storage_getmount_obj, storage_getmount);
@@ -156,7 +156,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(storage_getmount_obj, storage_getmount);
 //|     ...
 //|
 
-mp_obj_t storage_erase_filesystem(void) {
+STATIC mp_obj_t storage_erase_filesystem(void) {
     common_hal_storage_erase_filesystem();
     return mp_const_none;
 }
diff --git a/shared-bindings/time/__init__.c b/shared-bindings/time/__init__.c
index 971d381ede..4b090fc34e 100644
--- a/shared-bindings/time/__init__.c
+++ b/shared-bindings/time/__init__.c
@@ -93,7 +93,7 @@ STATIC mp_obj_t time_sleep(mp_obj_t seconds_o) {
 MP_DEFINE_CONST_FUN_OBJ_1(time_sleep_obj, time_sleep);
 
 #if MICROPY_PY_COLLECTIONS
-mp_obj_t struct_time_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t struct_time_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 1, 1, false);
     size_t len;
     mp_obj_t *items;
diff --git a/shared-module/_bleio/ScanEntry.c b/shared-module/_bleio/ScanEntry.c
index 065d23d4f4..7a57d8aedc 100644
--- a/shared-module/_bleio/ScanEntry.c
+++ b/shared-module/_bleio/ScanEntry.c
@@ -29,6 +29,7 @@
 #include <string.h>
 
 #include "shared-bindings/_bleio/Address.h"
+#include "shared-bindings/_bleio/ScanEntry.h"
 #include "shared-module/_bleio/Address.h"
 #include "shared-module/_bleio/ScanEntry.h"
 
diff --git a/shared-module/_eve/__init__.c b/shared-module/_eve/__init__.c
index 0df77b65cb..a39e6f9ee8 100644
--- a/shared-module/_eve/__init__.c
+++ b/shared-module/_eve/__init__.c
@@ -27,6 +27,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include "py/runtime.h"
+#include "shared-bindings/_eve/__init__.h"
 #include "shared-module/_eve/__init__.h"
 
 STATIC void write(common_hal__eve_t *eve, size_t len, void *buf) {
diff --git a/shared-module/adafruit_pixelbuf/PixelBuf.c b/shared-module/adafruit_pixelbuf/PixelBuf.c
index 378efbfde5..bfeab4ae04 100644
--- a/shared-module/adafruit_pixelbuf/PixelBuf.c
+++ b/shared-module/adafruit_pixelbuf/PixelBuf.c
@@ -140,7 +140,7 @@ void common_hal_adafruit_pixelbuf_pixelbuf_set_brightness(mp_obj_t self_in, mp_f
     }
 }
 
-uint8_t _pixelbuf_get_as_uint8(mp_obj_t obj) {
+STATIC uint8_t _pixelbuf_get_as_uint8(mp_obj_t obj) {
     if (mp_obj_is_small_int(obj)) {
         return MP_OBJ_SMALL_INT_VALUE(obj);
     } else if (mp_obj_is_int(obj)) {
@@ -152,7 +152,7 @@ uint8_t _pixelbuf_get_as_uint8(mp_obj_t obj) {
         translate("can't convert %q to %q"), mp_obj_get_type_qstr(obj), MP_QSTR_int);
 }
 
-void _pixelbuf_parse_color(pixelbuf_pixelbuf_obj_t *self, mp_obj_t color, uint8_t *r, uint8_t *g, uint8_t *b, uint8_t *w) {
+STATIC void _pixelbuf_parse_color(pixelbuf_pixelbuf_obj_t *self, mp_obj_t color, uint8_t *r, uint8_t *g, uint8_t *b, uint8_t *w) {
     pixelbuf_byteorder_details_t *byteorder = &self->byteorder;
     // w is shared between white in NeoPixels and brightness in dotstars (so that DotStars can have
     // per-pixel brightness). Set the defaults here in case it isn't set below.
@@ -197,7 +197,7 @@ void _pixelbuf_parse_color(pixelbuf_pixelbuf_obj_t *self, mp_obj_t color, uint8_
     }
 }
 
-void _pixelbuf_set_pixel_color(pixelbuf_pixelbuf_obj_t *self, size_t index, uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
+STATIC void _pixelbuf_set_pixel_color(pixelbuf_pixelbuf_obj_t *self, size_t index, uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
     // DotStars don't have white, instead they have 5 bit brightness so pack it into w. Shift right
     // by three to leave the top five bits.
     if (self->bytes_per_pixel == 4 && self->byteorder.is_dotstar) {
@@ -235,7 +235,7 @@ void _pixelbuf_set_pixel_color(pixelbuf_pixelbuf_obj_t *self, size_t index, uint
     }
 }
 
-void _pixelbuf_set_pixel(pixelbuf_pixelbuf_obj_t *self, size_t index, mp_obj_t value) {
+STATIC void _pixelbuf_set_pixel(pixelbuf_pixelbuf_obj_t *self, size_t index, mp_obj_t value) {
     uint8_t r;
     uint8_t g;
     uint8_t b;
diff --git a/shared-module/audiocore/WaveFile.c b/shared-module/audiocore/WaveFile.c
index 14c92ca411..0cceb979a6 100644
--- a/shared-module/audiocore/WaveFile.c
+++ b/shared-module/audiocore/WaveFile.c
@@ -160,14 +160,6 @@ uint8_t common_hal_audioio_wavefile_get_channel_count(audioio_wavefile_obj_t *se
     return self->channel_count;
 }
 
-bool audioio_wavefile_samples_signed(audioio_wavefile_obj_t *self) {
-    return self->bits_per_sample > 8;
-}
-
-uint32_t audioio_wavefile_max_buffer_length(audioio_wavefile_obj_t *self) {
-    return 512;
-}
-
 void audioio_wavefile_reset_buffer(audioio_wavefile_obj_t *self,
     bool single_channel_output,
     uint8_t channel) {
diff --git a/shared-module/audiomixer/MixerVoice.c b/shared-module/audiomixer/MixerVoice.c
index 34fa907a5b..bb58b0c111 100644
--- a/shared-module/audiomixer/MixerVoice.c
+++ b/shared-module/audiomixer/MixerVoice.c
@@ -24,6 +24,7 @@
  * THE SOFTWARE.
  */
 #include "shared-bindings/audiomixer/Mixer.h"
+#include "shared-bindings/audiomixer/MixerVoice.h"
 #include "shared-module/audiomixer/MixerVoice.h"
 
 #include <stdint.h>
diff --git a/shared-module/audiomp3/MP3Decoder.c b/shared-module/audiomp3/MP3Decoder.c
index cc755d7d2f..5e1bce5924 100644
--- a/shared-module/audiomp3/MP3Decoder.c
+++ b/shared-module/audiomp3/MP3Decoder.c
@@ -290,10 +290,6 @@ uint8_t common_hal_audiomp3_mp3file_get_channel_count(audiomp3_mp3file_obj_t *se
     return self->channel_count;
 }
 
-bool audiomp3_mp3file_samples_signed(audiomp3_mp3file_obj_t *self) {
-    return true;
-}
-
 void audiomp3_mp3file_reset_buffer(audiomp3_mp3file_obj_t *self,
     bool single_channel_output,
     uint8_t channel) {
diff --git a/shared-module/bitmaptools/__init__.c b/shared-module/bitmaptools/__init__.c
index a9cb3ae978..0c577f0194 100644
--- a/shared-module/bitmaptools/__init__.c
+++ b/shared-module/bitmaptools/__init__.c
@@ -219,17 +219,6 @@ void common_hal_bitmaptools_rotozoom(displayio_bitmap_t *self, int16_t ox, int16
     }
 }
 
-int16_t constrain(int16_t input, int16_t min, int16_t max) {
-    // constrain the input between the min and max values
-    if (input < min) {
-        return min;
-    }
-    if (input > max) {
-        return max;
-    }
-    return input;
-}
-
 void common_hal_bitmaptools_fill_region(displayio_bitmap_t *destination,
     int16_t x1, int16_t y1,
     int16_t x2, int16_t y2,
diff --git a/shared-module/board/__init__.c b/shared-module/board/__init__.c
index 05900040d8..19d9e7ece0 100644
--- a/shared-module/board/__init__.c
+++ b/shared-module/board/__init__.c
@@ -24,7 +24,9 @@
  * THE SOFTWARE.
  */
 
+#include "shared-bindings/board/__init__.h"
 #include "shared-bindings/microcontroller/Pin.h"
+#include "shared-module/board/__init__.h"
 #include "supervisor/shared/translate.h"
 #include "mpconfigboard.h"
 #include "py/runtime.h"
diff --git a/shared-module/displayio/EPaperDisplay.c b/shared-module/displayio/EPaperDisplay.c
index 675691ed00..7d8fc0d26d 100644
--- a/shared-module/displayio/EPaperDisplay.c
+++ b/shared-module/displayio/EPaperDisplay.c
@@ -103,7 +103,7 @@ bool common_hal_displayio_epaperdisplay_show(displayio_epaperdisplay_obj_t *self
     return displayio_display_core_show(&self->core, root_group);
 }
 
-const displayio_area_t *displayio_epaperdisplay_get_refresh_areas(displayio_epaperdisplay_obj_t *self) {
+STATIC const displayio_area_t *displayio_epaperdisplay_get_refresh_areas(displayio_epaperdisplay_obj_t *self) {
     if (self->core.full_refresh) {
         self->core.area.next = NULL;
         return &self->core.area;
@@ -172,7 +172,7 @@ void displayio_epaperdisplay_change_refresh_mode_parameters(displayio_epaperdisp
     self->milliseconds_per_frame = seconds_per_frame * 1000;
 }
 
-void displayio_epaperdisplay_start_refresh(displayio_epaperdisplay_obj_t *self) {
+STATIC void displayio_epaperdisplay_start_refresh(displayio_epaperdisplay_obj_t *self) {
     // run start sequence
     self->core.bus_reset(self->core.bus);
 
@@ -192,7 +192,7 @@ uint32_t common_hal_displayio_epaperdisplay_get_time_to_refresh(displayio_epaper
     return self->milliseconds_per_frame - elapsed_time;
 }
 
-void displayio_epaperdisplay_finish_refresh(displayio_epaperdisplay_obj_t *self) {
+STATIC void displayio_epaperdisplay_finish_refresh(displayio_epaperdisplay_obj_t *self) {
     // Actually refresh the display now that all pixel RAM has been updated.
     displayio_display_core_begin_transaction(&self->core);
     self->core.send(self->core.bus, DISPLAY_COMMAND, self->chip_select, &self->refresh_display_command, 1);
@@ -230,7 +230,7 @@ uint16_t common_hal_displayio_epaperdisplay_get_rotation(displayio_epaperdisplay
 }
 
 
-bool displayio_epaperdisplay_refresh_area(displayio_epaperdisplay_obj_t *self, const displayio_area_t *area) {
+STATIC bool displayio_epaperdisplay_refresh_area(displayio_epaperdisplay_obj_t *self, const displayio_area_t *area) {
     uint16_t buffer_size = 128; // In uint32_ts
 
     displayio_area_t clipped;
diff --git a/shared-module/displayio/TileGrid.c b/shared-module/displayio/TileGrid.c
index 430cbc8409..044674f415 100644
--- a/shared-module/displayio/TileGrid.c
+++ b/shared-module/displayio/TileGrid.c
@@ -104,7 +104,7 @@ bool displayio_tilegrid_get_previous_area(displayio_tilegrid_t *self, displayio_
     return true;
 }
 
-void _update_current_x(displayio_tilegrid_t *self) {
+STATIC void _update_current_x(displayio_tilegrid_t *self) {
     uint16_t width;
     if (self->transpose_xy) {
         width = self->pixel_height;
@@ -137,7 +137,7 @@ void _update_current_x(displayio_tilegrid_t *self) {
     }
 }
 
-void _update_current_y(displayio_tilegrid_t *self) {
+STATIC void _update_current_y(displayio_tilegrid_t *self) {
     uint16_t height;
     if (self->transpose_xy) {
         height = self->pixel_width;
diff --git a/shared-module/keypad/EventQueue.c b/shared-module/keypad/EventQueue.c
index ddd1cd0e87..eeeceb78cf 100644
--- a/shared-module/keypad/EventQueue.c
+++ b/shared-module/keypad/EventQueue.c
@@ -25,6 +25,7 @@
  */
 
 #include "shared-bindings/keypad/Event.h"
+#include "shared-bindings/keypad/EventQueue.h"
 #include "shared-bindings/supervisor/__init__.h"
 #include "shared-module/keypad/EventQueue.h"
 
diff --git a/shared-module/msgpack/__init__.c b/shared-module/msgpack/__init__.c
index 1e865385d7..7a6892c51f 100644
--- a/shared-module/msgpack/__init__.c
+++ b/shared-module/msgpack/__init__.c
@@ -38,6 +38,8 @@
 
 #include "supervisor/shared/translate.h"
 #include "shared-bindings/msgpack/ExtType.h"
+#include "shared-bindings/msgpack/__init__.h"
+#include "shared-module/msgpack/__init__.h"
 
 ////////////////////////////////////////////////////////////////
 // stream management
diff --git a/shared-module/random/__init__.c b/shared-module/random/__init__.c
index 95ac3bc659..438eb24696 100644
--- a/shared-module/random/__init__.c
+++ b/shared-module/random/__init__.c
@@ -30,6 +30,7 @@
 
 #include "py/runtime.h"
 #include "shared-bindings/os/__init__.h"
+#include "shared-bindings/random/__init__.h"
 #include "shared-bindings/time/__init__.h"
 
 // Yasmarang random number generator
diff --git a/shared-module/rotaryio/IncrementalEncoder.c b/shared-module/rotaryio/IncrementalEncoder.c
index 89dea01cfe..27b9cdb64d 100644
--- a/shared-module/rotaryio/IncrementalEncoder.c
+++ b/shared-module/rotaryio/IncrementalEncoder.c
@@ -25,6 +25,7 @@
  */
 
 #if CIRCUITPY_ROTARYIO && CIRCUITPY_ROTARYIO_SOFTENCODER
+#include "shared-bindings/rotaryio/IncrementalEncoder.h"
 #include "shared-module/rotaryio/IncrementalEncoder.h"
 #include "common-hal/rotaryio/IncrementalEncoder.h"
 
diff --git a/shared-module/sdcardio/SDCard.c b/shared-module/sdcardio/SDCard.c
index f5ab97ebe5..9cbbf40819 100644
--- a/shared-module/sdcardio/SDCard.c
+++ b/shared-module/sdcardio/SDCard.c
@@ -28,6 +28,7 @@
 
 #include "shared-bindings/busio/SPI.h"
 #include "shared-bindings/digitalio/DigitalInOut.h"
+#include "shared-bindings/sdcardio/SDCard.h"
 #include "shared-bindings/time/__init__.h"
 #include "shared-bindings/util.h"
 #include "shared-module/sdcardio/SDCard.h"
@@ -325,7 +326,7 @@ void common_hal_sdcardio_sdcard_deinit(sdcardio_sdcard_obj_t *self) {
     common_hal_digitalio_digitalinout_deinit(&self->cs);
 }
 
-void common_hal_sdcardio_check_for_deinit(sdcardio_sdcard_obj_t *self) {
+STATIC void common_hal_sdcardio_check_for_deinit(sdcardio_sdcard_obj_t *self) {
     if (!self->bus) {
         raise_deinited_error();
     }
@@ -336,7 +337,7 @@ int common_hal_sdcardio_sdcard_get_blockcount(sdcardio_sdcard_obj_t *self) {
     return self->sectors;
 }
 
-int readinto(sdcardio_sdcard_obj_t *self, void *buf, size_t size) {
+STATIC int readinto(sdcardio_sdcard_obj_t *self, void *buf, size_t size) {
     uint8_t aux[2] = {0, 0};
     while (aux[0] != 0xfe) {
         common_hal_busio_spi_read(self->bus, aux, 1, 0xff);
@@ -349,7 +350,7 @@ int readinto(sdcardio_sdcard_obj_t *self, void *buf, size_t size) {
     return 0;
 }
 
-int readblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) {
+STATIC int readblocks(sdcardio_sdcard_obj_t *self, uint32_t start_block, mp_buffer_info_t *buf) {
     uint32_t nblocks = buf->len / 512;
     if (nblocks == 1) {
         //  Use CMD17 to read a single block
diff --git a/shared-module/sharpdisplay/SharpMemoryFramebuffer.c b/shared-module/sharpdisplay/SharpMemoryFramebuffer.c
index 14f4908222..9012a5ac89 100644
--- a/shared-module/sharpdisplay/SharpMemoryFramebuffer.c
+++ b/shared-module/sharpdisplay/SharpMemoryFramebuffer.c
@@ -53,19 +53,19 @@ int common_hal_sharpdisplay_framebuffer_get_height(sharpdisplay_framebuffer_obj_
     return self->height;
 }
 
-int common_hal_sharpdisplay_framebuffer_get_row_stride(sharpdisplay_framebuffer_obj_t *self) {
+STATIC int common_hal_sharpdisplay_framebuffer_get_row_stride(sharpdisplay_framebuffer_obj_t *self) {
     return (self->width + 7) / 8 + 2;
 }
 
-int common_hal_sharpdisplay_framebuffer_get_first_pixel_offset(sharpdisplay_framebuffer_obj_t *self) {
+STATIC int common_hal_sharpdisplay_framebuffer_get_first_pixel_offset(sharpdisplay_framebuffer_obj_t *self) {
     return 2;
 }
 
-bool common_hal_sharpdisplay_framebuffer_get_reverse_pixels_in_byte(sharpdisplay_framebuffer_obj_t *self) {
+STATIC bool common_hal_sharpdisplay_framebuffer_get_reverse_pixels_in_byte(sharpdisplay_framebuffer_obj_t *self) {
     return true;
 }
 
-bool common_hal_sharpdisplay_framebuffer_get_pixels_in_byte_share_row(sharpdisplay_framebuffer_obj_t *self) {
+STATIC bool common_hal_sharpdisplay_framebuffer_get_pixels_in_byte_share_row(sharpdisplay_framebuffer_obj_t *self) {
     return true;
 }
 
@@ -143,7 +143,7 @@ void common_hal_sharpdisplay_framebuffer_construct(sharpdisplay_framebuffer_obj_
     common_hal_sharpdisplay_framebuffer_get_bufinfo(self, NULL);
 }
 
-void common_hal_sharpdisplay_framebuffer_swapbuffers(sharpdisplay_framebuffer_obj_t *self, uint8_t *dirty_row_bitmask) {
+STATIC void common_hal_sharpdisplay_framebuffer_swapbuffers(sharpdisplay_framebuffer_obj_t *self, uint8_t *dirty_row_bitmask) {
     // claim SPI bus
     if (!common_hal_busio_spi_try_lock(self->bus)) {
         return;
diff --git a/shared-module/struct/__init__.c b/shared-module/struct/__init__.c
index b3b0096174..a0abd16408 100644
--- a/shared-module/struct/__init__.c
+++ b/shared-module/struct/__init__.c
@@ -32,8 +32,9 @@
 #include "py/binary.h"
 #include "py/parsenum.h"
 #include "supervisor/shared/translate.h"
+#include "shared-bindings/struct/__init__.h"
 
-void struct_validate_format(char fmt) {
+STATIC void struct_validate_format(char fmt) {
     #if MICROPY_NONSTANDARD_TYPECODES
     if (fmt == 'S' || fmt == 'O') {
         mp_raise_RuntimeError(translate("'S' and 'O' are not supported format types"));
@@ -41,7 +42,7 @@ void struct_validate_format(char fmt) {
     #endif
 }
 
-char get_fmt_type(const char **fmt) {
+STATIC char get_fmt_type(const char **fmt) {
     char t = **fmt;
     switch (t) {
         case '!':
@@ -60,7 +61,7 @@ char get_fmt_type(const char **fmt) {
     return t;
 }
 
-mp_uint_t get_fmt_num(const char **p) {
+STATIC mp_uint_t get_fmt_num(const char **p) {
     const char *num = *p;
     uint len = 1;
     while (unichar_isdigit(*++num)) {
@@ -71,7 +72,7 @@ mp_uint_t get_fmt_num(const char **p) {
     return val;
 }
 
-mp_uint_t calcsize_items(const char *fmt) {
+STATIC mp_uint_t calcsize_items(const char *fmt) {
     mp_uint_t cnt = 0;
     while (*fmt) {
         int num = 1;
diff --git a/shared-module/terminalio/Terminal.c b/shared-module/terminalio/Terminal.c
index 48010aa650..f0a69bde39 100644
--- a/shared-module/terminalio/Terminal.c
+++ b/shared-module/terminalio/Terminal.c
@@ -28,6 +28,7 @@
 
 #include "shared-module/fontio/BuiltinFont.h"
 #include "shared-bindings/displayio/TileGrid.h"
+#include "shared-bindings/terminalio/Terminal.h"
 
 void common_hal_terminalio_terminal_construct(terminalio_terminal_obj_t *self, displayio_tilegrid_t *tilegrid, const fontio_builtinfont_t *font) {
     self->cursor_x = 0;
diff --git a/shared-module/time/__init__.c b/shared-module/time/__init__.c
index c79a5f3ae7..b4575b18a2 100644
--- a/shared-module/time/__init__.c
+++ b/shared-module/time/__init__.c
@@ -27,6 +27,7 @@
 #include "py/mphal.h"
 #include "supervisor/port.h"
 #include "supervisor/shared/tick.h"
+#include "shared-bindings/time/__init__.h"
 
 uint64_t common_hal_time_monotonic_ms(void) {
     return supervisor_ticks_ms64();
diff --git a/shared-module/vectorio/Rectangle.c b/shared-module/vectorio/Rectangle.c
index 2471daa608..bcaa0092f8 100644
--- a/shared-module/vectorio/Rectangle.c
+++ b/shared-module/vectorio/Rectangle.c
@@ -28,11 +28,6 @@ void common_hal_vectorio_rectangle_get_area(void *rectangle, displayio_area_t *o
 }
 
 
-uint32_t common_hal_vectorio_rectangle_get_height(void *rectangle) {
-    vectorio_rectangle_t *self = rectangle;
-    return self->height;
-}
-
 mp_obj_t common_hal_vectorio_rectangle_get_draw_protocol(void *rectangle) {
     vectorio_rectangle_t *self = rectangle;
     return self->draw_protocol_instance;
diff --git a/shared/runtime/interrupt_char.c b/shared/runtime/interrupt_char.c
index 4ac099f41e..21e5a06358 100644
--- a/shared/runtime/interrupt_char.c
+++ b/shared/runtime/interrupt_char.c
@@ -26,6 +26,7 @@
 
 #include "py/obj.h"
 #include "py/mpstate.h"
+#include "shared/runtime/interrupt_char.h"
 
 #if MICROPY_KBD_EXCEPTION
 
diff --git a/shared/runtime/sys_stdio_mphal.c b/shared/runtime/sys_stdio_mphal.c
index 228529ce3d..580d97f614 100644
--- a/shared/runtime/sys_stdio_mphal.c
+++ b/shared/runtime/sys_stdio_mphal.c
@@ -52,7 +52,7 @@ typedef struct _sys_stdio_obj_t {
 STATIC const sys_stdio_obj_t stdio_buffer_obj;
 #endif
 
-void stdio_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+STATIC void stdio_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     sys_stdio_obj_t *self = MP_OBJ_TO_PTR(self_in);
     mp_printf(print, "<io.FileIO %d>", self->fd);
 }