diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -142,7 +142,7 @@ SYSTEM_BUILD_DIR = $(BUILD_DIR)/system
 #OBJECTS = $(addprefix $(BUILD_DIR)/,$(notdir $(SOURCES:.c=.o)))
 OBJECTS = $(addprefix $(BUILD_DIR)/,$(SOURCES:.c=.o))
 # add an object for the startup code
-OBJECTS += $(BUILD_DIR)/startup_stm32f042x6.o
+OBJECTS += $(BUILD_DIR)/system/startup_stm32f042x6.o
 
 # use the periphlib core library, plus generic ones (libc, libm, libnosys)
 LIBS = -lstm32cube -lc -lm -lnosys
diff --git a/display.c b/display.c
--- a/display.c
+++ b/display.c
@@ -8,14 +8,14 @@
 #include "flash.h"
 #include "gpio.h"
 
-uint8_t goto_mode = 2;
+static uint8_t goto_mode = 2;
 
 // State machine
-uint8_t sw_btn_last = 0;
-uint8_t sw_up_last = 0;
-uint8_t sw_down_last = 0;
-uint8_t sw_left_last = 0;
-uint8_t sw_right_last = 0;
+static uint8_t sw_btn_last = 0;
+static uint8_t sw_up_last = 0;
+static uint8_t sw_down_last = 0;
+static uint8_t sw_left_last = 0;
+static uint8_t sw_right_last = 0;
 
 #define SW_BTN_PRESSED (sw_btn_last == 0 && sw_btn == 1) // rising edge on buttonpress
 #define SW_UP_PRESSED (sw_up_last == 0 && sw_up == 1)
@@ -24,9 +24,9 @@ uint8_t sw_right_last = 0;
 #define SW_RIGHT_PRESSED (sw_right_last == 0 && sw_right == 1)
 
 
-uint8_t trigger_drawsetpoint = 1;
+static uint8_t trigger_drawsetpoint = 1;
 
-int16_t last_temp = 21245;
+static int16_t last_temp = 21245;
 
 void display_process(therm_settings_t* set, therm_status_t* status)
 {
@@ -505,8 +505,8 @@ void display_process(therm_settings_t* s
 }
 
 
-int32_t temp_last = 43002;
-int32_t setpoint_last = 10023;
+static int32_t temp_last = 43002;
+static int32_t setpoint_last = 10023;
 void draw_setpoint(therm_status_t* status) {
     // FIXME: need to do this when switching modes too
     if(status->temp != temp_last || trigger_drawsetpoint) { 
diff --git a/gpio.c b/gpio.c
--- a/gpio.c
+++ b/gpio.c
@@ -36,7 +36,7 @@ void user_input_signed(int16_t* to_modif
 }
 
 
-void init_gpio(void) {
+void gpio_init(void) {
 
   GPIO_InitTypeDef GPIO_InitStruct;
 
diff --git a/gpio.h b/gpio.h
--- a/gpio.h
+++ b/gpio.h
@@ -10,7 +10,7 @@
 
 void user_input(uint16_t* to_modify);
 void user_input_signed(int16_t* to_modify);
-void init_gpio(void);
+void gpio_init(void);
 
 #endif
 
diff --git a/main.c b/main.c
--- a/main.c
+++ b/main.c
@@ -23,29 +23,21 @@ therm_settings_t set;
 therm_status_t status;
 
 // Globalish setting vars
-SPI_HandleTypeDef hspi1;
 static __IO uint32_t TimingDelay;
 
-void deinit(void)
-{
-    HAL_DeInit();
-}
-
-volatile int i=0;
 int main(void)
 {
-
     // Initialize HAL
     hal_init();
 
     // Configure the system clock
-    systemclock_config();
+    systemclock_init();
 
     // Unset bootloader option bytes (if set)
     void bootloader_unset(void);
 
     // Init GPIO
-    init_gpio();
+    gpio_init();
 
     // Init USB (TODO: Handle plugged/unplugged with external power)
     MX_USB_DEVICE_Init();
@@ -60,7 +52,7 @@ int main(void)
         bootloader_enter(); 
 
     // Init SPI busses
-    init_spi();
+    spi_init();
 
     // Init OLED over SPI
     ssd1306_Init();
@@ -189,7 +181,7 @@ void process()
     if((ticks - last_pid > PID_PERIOD))
     {
         #ifdef MAX31855_TC_SENSOR
-        max31855_readtemp(&hspi1, &set, &status); // Read MAX31855
+        max31855_readtemp(spi_get(), &set, &status); // Read MAX31855
         #endif
 
         #ifdef MAX31865_RTD_SENSOR
diff --git a/spi.c b/spi.c
--- a/spi.c
+++ b/spi.c
@@ -1,9 +1,9 @@
 
 #include "stm32f0xx_hal_conf.h"
 #include "stm32f0xx_hal_gpio_ex.h"
-extern SPI_HandleTypeDef hspi1;
+SPI_HandleTypeDef hspi1;
 
-void init_spi()
+void spi_init()
 {
     hspi1.Instance = SPI1;
     hspi1.Init.Mode = SPI_MODE_MASTER;
@@ -20,4 +20,9 @@ void init_spi()
     HAL_SPI_Init(&hspi1);
 }    
     
+SPI_HandleTypeDef* spi_get()
+{
+    return &hspi1;
+}
+
 // vim:softtabstop=4 shiftwidth=4 expandtab 
diff --git a/spi.h b/spi.h
--- a/spi.h
+++ b/spi.h
@@ -3,7 +3,8 @@
 
 #include "stm32f0xx_hal_conf.h"
 
-void init_spi();
+void spi_init();
+SPI_HandleTypeDef* spi_get();
 
 #endif
 
diff --git a/ssd1306.c b/ssd1306.c
--- a/ssd1306.c
+++ b/ssd1306.c
@@ -62,7 +62,7 @@ void ssd1306_Init(void)
 
 
 // Times New Roman font
-const char fontData[][5] =
+static const char fontData[][5] =
 {                                       // Refer to "Times New Roman" Font Database
                                         //   Basic Characters
     {0x00,0x00,0x00,0x00,0x00},         //   (  0)    - 0x0020 No-Break Space
diff --git a/system/interrupts.c b/system/interrupts.c
--- a/system/interrupts.c
+++ b/system/interrupts.c
@@ -1,81 +1,17 @@
-/**
-  ******************************************************************************
-  * @file    stm32f0xx_it.c
-  * @date    05/12/2014 20:22:27
-  * @brief   Interrupt Service Routines.
-  ******************************************************************************
-  *
-  * COPYRIGHT(c) 2014 STMicroelectronics
-  *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-  *
-  ******************************************************************************
-  */
-/* Includes ------------------------------------------------------------------*/
 #include "stm32f0xx_hal.h"
 #include "stm32f0xx.h"
 #include "interrupts.h"
-/* USER CODE BEGIN 0 */
-
-/* USER CODE END 0 */
-/* External variables --------------------------------------------------------*/
 
 extern PCD_HandleTypeDef hpcd_USB_FS;
 
-/******************************************************************************/
-/*            Cortex-M0 Processor Interruption and Exception Handlers         */ 
-/******************************************************************************/
-
-/**
-* @brief This function handles USB global Interrupt (combined with EXTI line 18).
-*/
 void USB_IRQHandler(void)
 {
-  /* USER CODE BEGIN USB_IRQn 0 */
-
-  /* USER CODE END USB_IRQn 0 */
   HAL_PCD_IRQHandler(&hpcd_USB_FS);
-  /* USER CODE BEGIN USB_IRQn 1 */
-
-  /* USER CODE END USB_IRQn 1 */
 }
 
-/**
-* @brief This function handles System tick timer.
-*/
 void SysTick_Handler(void)
 {
-  /* USER CODE BEGIN SysTick_IRQn 0 */
-
-  /* USER CODE END SysTick_IRQn 0 */
   HAL_IncTick();
   HAL_SYSTICK_IRQHandler();
-  /* USER CODE BEGIN SysTick_IRQn 1 */
-
-  /* USER CODE END SysTick_IRQn 1 */
 }
 
-/* USER CODE BEGIN 1 */
-
-/* USER CODE END 1 */
-/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
diff --git a/system/interrupts.h b/system/interrupts.h
--- a/system/interrupts.h
+++ b/system/interrupts.h
@@ -1,38 +1,3 @@
-/**
-  ******************************************************************************
-  * @file    stm32f0xx_it.h
-  * @date    05/12/2014 20:22:27
-  * @brief   This file contains the headers of the interrupt handlers.
-  ******************************************************************************
-  *
-  * COPYRIGHT(c) 2014 STMicroelectronics
-  *
-  * Redistribution and use in source and binary forms, with or without modification,
-  * are permitted provided that the following conditions are met:
-  *   1. Redistributions of source code must retain the above copyright notice,
-  *      this list of conditions and the following disclaimer.
-  *   2. Redistributions in binary form must reproduce the above copyright notice,
-  *      this list of conditions and the following disclaimer in the documentation
-  *      and/or other materials provided with the distribution.
-  *   3. Neither the name of STMicroelectronics nor the names of its contributors
-  *      may be used to endorse or promote products derived from this software
-  *      without specific prior written permission.
-  *
-  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
-  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-  *
-  ******************************************************************************
-  */
-
-/* Define to prevent recursive inclusion -------------------------------------*/
 #ifndef __STM32F0xx_IT_H
 #define __STM32F0xx_IT_H
 
@@ -40,12 +5,6 @@
  extern "C" {
 #endif 
 
-/* Includes ------------------------------------------------------------------*/
-/* Exported types ------------------------------------------------------------*/
-/* Exported constants --------------------------------------------------------*/
-/* Exported macro ------------------------------------------------------------*/
-/* Exported functions ------------------------------------------------------- */
-
 void USB_IRQHandler(void);
 void SysTick_Handler(void);
 
@@ -54,5 +13,3 @@ void SysTick_Handler(void);
 #endif
 
 #endif /* __STM32F0xx_IT_H */
-
-/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
diff --git a/system/syslib.c b/system/syslib.c
--- a/system/syslib.c
+++ b/system/syslib.c
@@ -62,7 +62,7 @@ void bootloader_enter(void) {
 
 
 // Clock configuration
-void systemclock_config(void)
+void systemclock_init(void)
 {
 
   RCC_OscInitTypeDef RCC_OscInitStruct;
diff --git a/system/syslib.h b/system/syslib.h
--- a/system/syslib.h
+++ b/system/syslib.h
@@ -3,6 +3,6 @@
 
 void bootloader_unset(void);
 void bootloader_enter(void);
-void systemclock_config(void);
+void systemclock_init(void);
 
 #endif
diff --git a/system/usbd_conf.c b/system/usbd_conf.c
--- a/system/usbd_conf.c
+++ b/system/usbd_conf.c
@@ -53,7 +53,7 @@ PCD_HandleTypeDef hpcd_USB_FS;
 static void SystemClockConfig_Resume(void);
 /* USER CODE END 1 */
 void HAL_PCDEx_SetConnectionState(PCD_HandleTypeDef *hpcd, uint8_t state);
-extern void systemclock_config(void);
+extern void systemclock_init(void);
 
 /*******************************************************************************
 		       LL Driver Callbacks (PCD -> USB Device Library)
@@ -502,7 +502,7 @@ void USBD_static_free(void *p)
   */
 static void SystemClockConfig_Resume(void)
 {
-	systemclock_config();
+	systemclock_init();
 }
 /* USER CODE END 4 */