diff --git a/.gitignore b/.gitignore
index 9226a25..628444f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,8 @@
 project.elf
 *.o
 *.map
-
+*.bin
+*.hex
 *.user
 *.user*
 *.user.*
diff --git a/main.c b/main.c
index 1261905..f6ef94d 100644
--- a/main.c
+++ b/main.c
@@ -5,7 +5,15 @@ unsigned int i = 0x12345678;
 unsigned char c = 2;
 
 int main(void) {
+	RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN;
+	GPIOB->MODER |= (1<<14*2) | (1<<7*2) | (1<<0*2);
+	GPIOB->ODR |= (1<<14) | (1<<0);
+	SysTick_Config(800000);
 	while(1) {
 		i++;
 	}
 }
+
+void SysTick_Handler(void) {
+	GPIOB->ODR ^= (1<<14) | (1<<7) | 1;
+}
diff --git a/setup/system_init.c b/setup/system_init.c
index 27b89a3..00304f7 100644
--- a/setup/system_init.c
+++ b/setup/system_init.c
@@ -1,16 +1,77 @@
 #include <stm32f7xx.h>
 
+const signed char __pll_main_div_q_val[] = {-1, -1, 2, 3, 4, 5, 6, 7, 8 ,9, 10, 11, 12, 13, 14, 15};
+const signed char __pll_main_div_p_val[] = {-1, -1, 0, -1, 1, -1, 2, -1, 3};
+const signed char __mco_div_val[] = {-1, 0, 4, 5, 6, 7};
+const signed char __apb_presc_val[] = {-1, 0, 4, -1, 5, -1, -1, -1, 6, -1, -1, -1, -1, -1, -1, -1, 7};
+#define SYSINIT_MAIN_I2S_PLL_DIV_M_MIN (2)
+#define SYSINIT_MAIN_I2S_PLL_DIV_M_MAX (63)
+#define SYSINIT_MAIN_I2S_PLL_MULT_N_MIN (2)
+#define SYSINIT_MAIN_I2S_PLL_MULT_N_MAX (432)
+#define SYSINIT_MAIN_I2S_PLL_SRC_HSE (1)
+#define SYSINIT_MAIN_I2S_PLL_SRC_HSI (0)
+
+#define SYSINIT_MCO2_SRC_SYSCLK (0)
+#define SYSINIT_MCO2_SRC_PLLI2S (1)
+#define SYSINIT_MCO2_SRC_HSE (2)
+#define SYSINIT_MCO2_SRC_PLL (3)
+
+#define SYSINIT_MCO1_SRC_HSI (0)
+#define SYSINIT_MCO1_SRC_LSE (1)
+#define SYSINIT_MCO1_SRC_HSE (2)
+#define SYSINIT_MCO1_SRC_PLL (3)
+
+#define SYSINIT_I2S_SRC_PLLI2S (0)
+#define SYSINIT_I2S_SRC_CKIN (1)
+
+#define SYSINIT_SYSCLK_SRC_HSI (0)
+#define SYSINIT_SYSCLK_SRC_HSE (1)
+#define SYSINIT_SYSCLK_SRC_PLL (2)
+
+enum sysinit_ahb_presc {DIV1 = 0, DIV2 = 8, DIV4 = 9, DIV8 = 10, DIV16 = 11, DIV64 =12, DIV128 = 13, DIV256 = 14, DIV512 = 15};
+
+struct clock_config {
+	uint32_t hsi_enable : 1;
+	uint32_t hse_enable : 1;
+	uint32_t lsi_enable : 1;
+	uint32_t lse_enable : 1;
+	uint32_t pll_sai_on : 1;
+	uint32_t pll_i2s_on : 1;
+	uint32_t pll_main_on : 1;
+	uint32_t css_on	: 1;
+	uint32_t hse_bypass : 1;
+	uint32_t hsi_trim : 5;
+	/* Main PLL Conf */
+	uint32_t pll_main_i2s_src : 1;
+	uint32_t pll_main_div_q : 4; /* true value */
+	uint32_t pll_main_div_p : 3; /* true value */
+	uint32_t pll_main_mult_n : 9;
+	uint32_t pll_main_div_m : 6;
+	/* MCO Outputs */
+	uint32_t mco2_sel : 2;
+	uint32_t mco2_presc : 3;
+	uint32_t mco1_sel : 2;
+	/* I2S clock selection */
+	uint32_t i2s_src : 1;
+	/* RTC */
+	uint32_t rtc_hse_div_1_meg : 5;
+	/* APB */
+	uint32_t apb1_presc : 5;
+	uint32_t apb2_presc : 5;
+	/* Systemclock */
+	uint32_t sysclk_src : 2;
+	
+	
+	/* AHB */
+	enum sysinit_ahb_presc ahb_presc;
+};
+
 
 #define VECT_TAB_OFFSET (0x0)
 
-
-
-void __system_init(void) {
-	/* FPU settings ------------------------------------------------------------*/
-  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
-    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */
-  #endif
-  /* Reset the RCC clock configuration to the default reset state ------------*/
+static void __init_default_clocks(void)
+{
+	 /* Reset the RCC clock configuration to the default reset state ------------*/
   /* Set HSION bit */
   RCC->CR |= (uint32_t)0x00000001;
 
@@ -36,3 +97,15 @@ void __system_init(void) {
   SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
 #endif
 }
+
+
+void __system_init(void)
+{
+	/* FPU settings ------------------------------------------------------------*/
+  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
+    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */
+  #endif
+
+ __init_default_clocks();
+ 
+}