add custom IO initialization code

- add custom IO initialization code (overridable)

uCNC/src/cnc.c

@@ -112,6 +112,7 @@ void cnc_init(void)
 	cnc_state.loop_state = LOOP_STARTUP_RESET;
 	// initializes all systems
 	mcu_init();											// mcu
+	mcu_io_reset();									// add custom logic to set pins initial state
 	io_enable_steppers(~g_settings.step_enable_invert); // disables steppers at start
 	io_disable_probe();									// forces probe isr disabling
 	serial_init();										// serial

uCNC/src/hal/mcus/mcu.c

@@ -716,6 +716,12 @@ void __attribute__((weak)) mcu_io_init(void)
 #endif
 }
 
+#ifndef mcu_io_reset
+void __attribute__((weak)) mcu_io_reset(void)
+{
+}
+#endif
+
 #ifdef BOARD_HAS_CUSTOM_SYSTEM_COMMANDS
 uint8_t __attribute__((weak)) mcu_custom_grbl_cmd(uint8_t *grbl_cmd_str, uint8_t grbl_cmd_len, uint8_t next_char)
 {
@@ -776,7 +782,7 @@ MCU_RX_CALLBACK void __attribute__((weak)) mcu_uart_rx_cb(uint8_t c) {}
 
 #ifdef MCU_HAS_UART2
 #ifdef DETACH_UART2_FROM_MAIN_PROTOCOL
-MCU_RX_CALLBACK void __attribute__((weak)) mcu_uart2_rx_cb(uint8_t c){}
+MCU_RX_CALLBACK void __attribute__((weak)) mcu_uart2_rx_cb(uint8_t c) {}
 #endif
 #endif
 

uCNC/src/hal/mcus/mcu.h

@@ -164,6 +164,13 @@ extern "C"
 	 * */
 	void mcu_io_init(void);
 
+	/**
+	 * This can be used to set the defaults state of IO pins on reset. (overridable)
+	 * */
+#ifndef mcu_io_reset
+	void mcu_io_reset(void);
+#endif
+
 	/**
 	 * initializes the mcu
 	 * this function needs to: