adafruit · tannewt · Jan 14, 2026 · Sep 17, 2026 · Sep 17, 2026 · Sep 17, 2026
diff --git a/main.c b/main.c
@@ -410,22 +410,20 @@ static void cleanup_after_vm(mp_obj_t exception) {
     wifi_user_reset();
     #endif
 
-    // reset_board_buses() first because it may release pins from the never_reset state, so that
-    // reset_port() can reset them.
+    // reset_board_buses() first to preserve display buses and deinit others.
     #if CIRCUITPY_BOARD
     reset_board_buses();
     #endif
-    reset_port();
-    reset_board();
 
-    // Free the heap last because other modules may reference heap memory and need to shut down.
+    // Flush before GC might free file objects.
     filesystem_flush();
 
-    // Runs finalisers while shutting down the heap.
+    // Runs finalisers while shutting down the heap. Finalizers call deinit on all user objects.
     stop_mp();
 
-    // Don't reset pins until finalisers have run.
-    reset_all_pins();
+    // Port-wide cleanup after finalizers have run.
+    reset_port();
+    reset_board();
 
     // Let the workflows know we've reset in case they want to restart.
     supervisor_workflow_reset();
@@ -804,8 +802,6 @@ static bool __attribute__((noinline)) run_code_py(safe_mode_t safe_mode, bool *s
         #if CIRCUITPY_ALARM_PRESERVE_DIOS
         common_hal_alarm_clear_pin_preservations();
         #endif
-        // Reset pins, as if there was a hard reset.
-        reset_all_pins();
         // Pretend that the next run is the first run, as if we were reset.
         *simulate_reset = true;
     }
@@ -1020,9 +1016,6 @@ int __attribute__((used)) main(void) {
     // initialise the cpu and peripherals
     set_safe_mode(port_init());
 
-    // All ports need pins reset, after never-reset pins are marked in port_init();
-    reset_all_pins();
-
     port_heap_init();
 
 

diff --git a/ports/analog/common-hal/busio/I2C.c b/ports/analog/common-hal/busio/I2C.c
@@ -96,12 +96,6 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
     return;
 }
 
-// Never reset I2C obj when reload
-void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
-    common_hal_never_reset_pin(self->sda);
-    common_hal_never_reset_pin(self->scl);
-}
-
 // Check I2C status, deinited or not
 bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
     return self->sda == NULL;

diff --git a/ports/analog/common-hal/busio/SPI.c b/ports/analog/common-hal/busio/SPI.c
@@ -114,14 +114,6 @@ void common_hal_busio_spi_construct(busio_spi_obj_t *self,
     return;
 }
 
-// Never reset SPI when reload
-void common_hal_busio_spi_never_reset(busio_spi_obj_t *self) {
-    common_hal_never_reset_pin(self->mosi);
-    common_hal_never_reset_pin(self->miso);
-    common_hal_never_reset_pin(self->sck);
-    common_hal_never_reset_pin(self->nss);
-}
-
 // Check SPI status, deinited or not
 bool common_hal_busio_spi_deinited(busio_spi_obj_t *self) {
     return self->sck == NULL;

diff --git a/ports/analog/common-hal/busio/UART.c b/ports/analog/common-hal/busio/UART.c
@@ -64,7 +64,6 @@ typedef enum {
 typedef enum {
     UART_FREE = 0,
     UART_BUSY,
-    UART_NEVER_RESET,
 } uart_status_t;
 
 static uint32_t timeout_ms = 0;
@@ -74,7 +73,6 @@ static uint32_t timeout_ms = 0;
 static uint8_t uarts_active = 0;
 static uart_status_t uart_status[NUM_UARTS];
 static volatile int uart_err;
-static uint8_t uart_never_reset_mask = 0;
 static busio_uart_obj_t *context;
 
 static bool isValidBaudrate(uint32_t baudrate) {
@@ -449,12 +447,4 @@ bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
     return !(MXC_UART_GetStatus(self->uart_regs) & (MXC_F_UART_STATUS_TX_BUSY));
 }
 
-void common_hal_busio_uart_never_reset(busio_uart_obj_t *self) {
-    common_hal_never_reset_pin(self->tx_pin);
-    common_hal_never_reset_pin(self->rx_pin);
-    common_hal_never_reset_pin(self->cts_pin);
-    common_hal_never_reset_pin(self->rts_pin);
-    uart_never_reset_mask |= (1 << (self->uart_id));
-}
-
 #endif // CIRCUITPY_BUSIO_UART
diff --git a/ports/analog/common-hal/digitalio/DigitalInOut.c b/ports/analog/common-hal/digitalio/DigitalInOut.c
@@ -14,11 +14,6 @@
 
 extern mxc_gpio_regs_t *gpio_ports[NUM_GPIO_PORTS];
 
-void common_hal_digitalio_digitalinout_never_reset(
-    digitalio_digitalinout_obj_t *self) {
-    common_hal_never_reset_pin(self->pin);
-}
-
 bool common_hal_digitalio_digitalinout_deinited(digitalio_digitalinout_obj_t *self) {
     return self->pin == NULL;
 }

diff --git a/ports/analog/common-hal/microcontroller/Pin.c b/ports/analog/common-hal/microcontroller/Pin.c
@@ -19,22 +19,8 @@ static uint32_t claimed_pins[NUM_GPIO_PORTS];
 // defined in board.c
 extern mxc_gpio_regs_t *gpio_ports[NUM_GPIO_PORTS];
 
-static uint32_t never_reset_pins[NUM_GPIO_PORTS];
-
 #define INVALID_PIN 0xFF // id for invalid pin
 
-void reset_all_pins(void) {
-    // reset all pins except for never_reset_pins
-    for (int i = 0; i < NUM_GPIO_PORTS; i++) {
-        for (int j = 0; j < 32; j++) {
-            if (!(never_reset_pins[i] & (1 << j))) {
-                reset_pin_number(i, j);
-            }
-        }
-        // set claimed pins to never_reset pins
-        claimed_pins[i] = never_reset_pins[i];
-    }
-}
 
 void reset_pin_number(uint8_t pin_port, uint8_t pin_pad) {
     if ((pin_port == INVALID_PIN) || (pin_port > NUM_GPIO_PORTS)) {
@@ -84,15 +70,6 @@ bool common_hal_mcu_pin_is_free(const mcu_pin_obj_t *pin) {
     return !(claimed_pins[pin->port] & (pin->mask));
 }
 
-void common_hal_never_reset_pin(const mcu_pin_obj_t *pin) {
-    if ((pin != NULL) && (pin->mask != INVALID_PIN)) {
-        never_reset_pins[pin->port] |= (1 << pin->mask);
-
-        // any never reset pin must also be claimed
-        claimed_pins[pin->port] |= (1 << pin->mask);
-    }
-}
-
 void common_hal_reset_pin(const mcu_pin_obj_t *pin) {
     if (pin == NULL) {
         return;

diff --git a/ports/analog/common-hal/microcontroller/Pin.h b/ports/analog/common-hal/microcontroller/Pin.h
@@ -10,7 +10,6 @@
 
 #include "peripherals/pins.h"
 
-void reset_all_pins(void);
 // reset_pin_number takes the pin number instead of the pointer so that objects don't
 // need to store a full pointer.
 void reset_pin_number(uint8_t pin_port, uint8_t pin_pad);
diff --git a/ports/analog/supervisor/usb.c b/ports/analog/supervisor/usb.c
@@ -19,7 +19,6 @@
 
 void init_usb_hardware(void) {
     // USB GPIOs are non-configurable on MAX32 devices
-    // No need to add them to the never_reset list for mcu/Pin API.
 
     // 1 ms SysTick initialized in board.c
 

diff --git a/ports/atmel-samd/boards/aloriumtech_evo_m51/board.c b/ports/atmel-samd/boards/aloriumtech_evo_m51/board.c
@@ -13,7 +13,6 @@
 #include "common-hal/microcontroller/Pin.h"
 
 void board_init(void) {
-    never_reset_pin_number(PIN_PB20);
     REG_PORT_DIRSET1 = PORT_PB20; // PB20 as output
     REG_PORT_OUTCLR1 = PORT_PB20; // PB20 cleared
     PORT->Group[1].PINCFG[20].reg |= PORT_PINCFG_PMUXEN;  // Mux enabled on PB20

diff --git a/ports/atmel-samd/boards/hallowing_m0_express/board.c b/ports/atmel-samd/boards/hallowing_m0_express/board.c
@@ -51,7 +51,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     bus->base.type = &fourwire_fourwire_type;
     busio_spi_obj_t *spi = common_hal_board_create_spi(0);
-    common_hal_busio_spi_never_reset(spi);
     common_hal_fourwire_fourwire_construct(bus,
         spi,
         MP_OBJ_FROM_PTR(&pin_PA28), // Command or data

diff --git a/ports/atmel-samd/boards/hallowing_m4_express/board.c b/ports/atmel-samd/boards/hallowing_m4_express/board.c
@@ -30,7 +30,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PA01, &pin_PA00, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/monster_m4sk/board.c b/ports/atmel-samd/boards/monster_m4sk/board.c
@@ -30,7 +30,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PA13, &pin_PA12, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/openbook_m4/board.c b/ports/atmel-samd/boards/openbook_m4/board.c
@@ -39,7 +39,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PB13, &pin_PB15, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/pewpew_lcd/board.c b/ports/atmel-samd/boards/pewpew_lcd/board.c
@@ -49,7 +49,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PA23, &pin_PA22, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/pewpew_m4/board.c b/ports/atmel-samd/boards/pewpew_m4/board.c
@@ -78,7 +78,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PA13, &pin_PA15, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/pybadge/board.c b/ports/atmel-samd/boards/pybadge/board.c
@@ -51,7 +51,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PB13, &pin_PB15, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/pycubed/board.c b/ports/atmel-samd/boards/pycubed/board.c
@@ -13,7 +13,6 @@
 void board_init(void) {
     pwmio_pwmout_obj_t pwm;
     common_hal_pwmio_pwmout_construct(&pwm, &pin_PA23, 4096, 2, false);
-    common_hal_pwmio_pwmout_never_reset(&pwm);
 }
 
 // Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/atmel-samd/boards/pycubed_mram/board.c b/ports/atmel-samd/boards/pycubed_mram/board.c
@@ -13,7 +13,6 @@
 void board_init(void) {
     pwmio_pwmout_obj_t pwm;
     common_hal_pwmio_pwmout_construct(&pwm, &pin_PA23, 4096, 2, false);
-    common_hal_pwmio_pwmout_never_reset(&pwm);
 }
 
 // Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/atmel-samd/boards/pycubed_mram_v05/board.c b/ports/atmel-samd/boards/pycubed_mram_v05/board.c
@@ -13,7 +13,6 @@
 void board_init(void) {
     pwmio_pwmout_obj_t pwm;
     common_hal_pwmio_pwmout_construct(&pwm, &pin_PA23, 4096, 2, false);
-    common_hal_pwmio_pwmout_never_reset(&pwm);
 }
 
 // Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/atmel-samd/boards/pycubed_v05/board.c b/ports/atmel-samd/boards/pycubed_v05/board.c
@@ -13,7 +13,6 @@
 void board_init(void) {
     pwmio_pwmout_obj_t pwm;
     common_hal_pwmio_pwmout_construct(&pwm, &pin_PA23, 4096, 2, false);
-    common_hal_pwmio_pwmout_never_reset(&pwm);
 }
 
 // Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/atmel-samd/boards/pygamer/board.c b/ports/atmel-samd/boards/pygamer/board.c
@@ -52,7 +52,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PB13, &pin_PB15, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,

diff --git a/ports/atmel-samd/boards/seeeduino_wio_terminal/board.c b/ports/atmel-samd/boards/seeeduino_wio_terminal/board.c
@@ -47,7 +47,6 @@ void board_init(void) {
     fourwire_fourwire_obj_t *bus = &allocate_display_bus()->fourwire_bus;
     busio_spi_obj_t *spi = &bus->inline_bus;
     common_hal_busio_spi_construct(spi, &pin_PB20, &pin_PB19, NULL, false);
-    common_hal_busio_spi_never_reset(spi);
 
     bus->base.type = &fourwire_fourwire_type;
     common_hal_fourwire_fourwire_construct(bus,
@@ -104,9 +103,6 @@ void board_init(void) {
     common_hal_digitalio_digitalinout_set_value(&USB_HOST_ENABLE, false);
 
     // Never reset
-    common_hal_digitalio_digitalinout_never_reset(&CTR_5V);
-    common_hal_digitalio_digitalinout_never_reset(&CTR_3V3);
-    common_hal_digitalio_digitalinout_never_reset(&USB_HOST_ENABLE);
 
     // reset pin after fake deep sleep
     reset_pin_number(pin_PA18.number);

diff --git a/ports/atmel-samd/boards/sparkfun_samd51_micromod/board.c b/ports/atmel-samd/boards/sparkfun_samd51_micromod/board.c
@@ -12,8 +12,6 @@
 
 void external_flash_setup(void) {
     // Do not reset the external flash write-protect and hold pins high
-    never_reset_pin_number(PIN_PB22);
-    never_reset_pin_number(PIN_PB23);
 
     // note: using output instead of input+pullups because the pullups are a little weak
     // Set the WP pin high

diff --git a/ports/atmel-samd/boards/uchip/board.c b/ports/atmel-samd/boards/uchip/board.c
@@ -13,13 +13,9 @@
 
 void board_init(void) {
     // BOOST_ENABLE
-    never_reset_pin_number(PIN_PA14);
     // VEXT_SELECT
-    never_reset_pin_number(PIN_PA15);
     // USB_DETECT
-    never_reset_pin_number(PIN_PA28);
     // USB_HOST_EN
-    never_reset_pin_number(PIN_PA27);
 }
 
 // Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/atmel-samd/boards/winterbloom_big_honking_button/usermods/_bhb/bhb.c b/ports/atmel-samd/boards/winterbloom_big_honking_button/usermods/_bhb/bhb.c
@@ -14,7 +14,6 @@ static mp_obj_t _bhb_read_adc(void);
 
 static mp_obj_t _bhb_init_adc(void) {
     claim_pin(&pin_PB08);
-    common_hal_never_reset_pin(&pin_PB08);
 
     /* Enable the APB clock for the ADC. */
     PM->APBCMASK.reg |= PM_APBCMASK_ADC;

diff --git a/ports/atmel-samd/common-hal/busio/I2C.c b/ports/atmel-samd/common-hal/busio/I2C.c
@@ -118,9 +118,6 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
     self->scl_pin = scl->number;
     claim_pin(sda);
     claim_pin(scl);
-
-    // Prevent bulk sercom reset from resetting us. The finalizer will instead.
-    never_reset_sercom(self->i2c_desc.device.hw);
 }
 
 bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
@@ -135,7 +132,6 @@ void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
     if (common_hal_busio_i2c_deinited(self)) {
         return;
     }
-    allow_reset_sercom(self->i2c_desc.device.hw);
 
     i2c_m_sync_disable(&self->i2c_desc);
     i2c_m_sync_deinit(&self->i2c_desc);
@@ -242,8 +238,3 @@ mp_negative_errno_t common_hal_busio_i2c_write_read(busio_i2c_obj_t *self, uint1
 
     return common_hal_busio_i2c_read(self, addr, in_data, in_len);
 }
-
-void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
-    never_reset_pin_number(self->scl_pin);
-    never_reset_pin_number(self->sda_pin);
-}
diff --git a/ports/atmel-samd/common-hal/busio/SPI.c b/ports/atmel-samd/common-hal/busio/SPI.c
@@ -172,13 +172,6 @@ void common_hal_busio_spi_construct(busio_spi_obj_t *self,
     spi_m_sync_enable(&self->spi_desc);
 }
 
-void common_hal_busio_spi_never_reset(busio_spi_obj_t *self) {
-    never_reset_sercom(self->spi_desc.dev.prvt);
-
-    never_reset_pin_number(self->clock_pin);
-    never_reset_pin_number(self->MOSI_pin);
-    never_reset_pin_number(self->MISO_pin);
-}
 
 bool common_hal_busio_spi_deinited(busio_spi_obj_t *self) {
     return self->clock_pin == NO_PIN;
@@ -192,7 +185,6 @@ void common_hal_busio_spi_deinit(busio_spi_obj_t *self) {
     if (common_hal_busio_spi_deinited(self)) {
         return;
     }
-    allow_reset_sercom(self->spi_desc.dev.prvt);
 
     spi_m_sync_disable(&self->spi_desc);
     spi_m_sync_deinit(&self->spi_desc);

diff --git a/ports/atmel-samd/common-hal/busio/UART.c b/ports/atmel-samd/common-hal/busio/UART.c
@@ -326,22 +326,6 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     usart_async_enable(usart_desc_p);
 }
 
-void common_hal_busio_uart_never_reset(busio_uart_obj_t *self) {
-    for (size_t i = 0; i < MP_ARRAY_SIZE(sercom_insts); i++) {
-        const Sercom *sercom = sercom_insts[i];
-        Sercom *hw = (Sercom *)(self->usart_desc.device.hw);
-
-        // Reserve pins for active UART only
-        if (sercom == hw) {
-            never_reset_sercom(hw);
-            never_reset_pin_number(self->rx_pin);
-            never_reset_pin_number(self->tx_pin);
-            never_reset_pin_number(self->rts_pin);
-            never_reset_pin_number(self->cts_pin);
-        }
-    }
-    return;
-}
 
 bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
     return self->rx_pin == NO_PIN && self->tx_pin == NO_PIN;