1 files changed, 82 insertions, 0 deletions
diff --git a/src/STM32F0xx_init.c b/src/STM32F0xx_init.c
new file mode 100644
index 0000000..904d9c0
--- /dev/null
+++ b/src/STM32F0xx_init.c
@@ -0,0 +1,82 @@
+#include "STM32F0xx.h"
+#include "common.h"
+
+/**
+ * Initialize the HSI clock source and reset the PLL configuration. This
+ * function is called by the startup_common.s file, just before calling the
+ * main() function.
+ */
+void SystemInit (void) {
+  // Set HSION bit
+  RCC->CR |= (uint32_t)0x00000001U;
+
+#if defined (STM32F051x8) || \
+    defined (STM32F058x8)
+  // Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE and MCOSEL[2:0] bits
+  RCC->CFGR &= (uint32_t)0xF8FFB80CU;
+#else
+  // Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE, MCOSEL[2:0], MCOPRE[2:0] and PLLNODIV bits
+  RCC->CFGR &= (uint32_t)0x08FFB80CU;
+#endif
+
+  // Reset HSEON, CSSON and PLLON bits
+  RCC->CR &= (uint32_t)0xFEF6FFFFU;
+
+  // Reset HSEBYP bit
+  RCC->CR &= (uint32_t)0xFFFBFFFFU;
+
+  // Reset PLLSRC, PLLXTPRE and PLLMUL[3:0] bits
+  RCC->CFGR &= (uint32_t)0xFFC0FFFFU;
+
+  // Reset PREDIV[3:0] bits
+  RCC->CFGR2 &= (uint32_t)0xFFFFFFF0U;
+
+#if defined (STM32F072xB) || \
+    defined (STM32F078xx)
+  // Reset USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFCFE2CU;
+
+#elif defined (STM32F071xB)
+  // Reset USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFFCEACU;
+
+#elif defined (STM32F091xC) || \
+      defined (STM32F098xx)
+  // Reset USART3SW[1:0], USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFF0FEACU;
+
+#elif defined (STM32F030x6) || \
+      defined (STM32F030x8) || \
+      defined (STM32F031x6) || \
+      defined (STM32F038xx) || \
+      defined (STM32F030xC)
+  // Reset USART1SW[1:0], I2C1SW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFFFEECU;
+
+#elif defined (STM32F051x8) || \
+      defined (STM32F058xx)
+  // Reset USART1SW[1:0], I2C1SW, CECSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFFFEACU;
+
+#elif defined (STM32F042x6) || \
+      defined (STM32F048xx)
+  // Reset USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFFFE2CU;
+
+#elif defined (STM32F070x6) || \
+      defined (STM32F070xB)
+  // Reset USART1SW[1:0], I2C1SW, USBSW and ADCSW bits
+  RCC->CFGR3 &= (uint32_t)0xFFFFFE6CU;
+  // Set default USB clock to PLLCLK, since there is no HSI48
+  RCC->CFGR3 |= (uint32_t)0x00000080U;
+
+#else
+  #warning "No target selected"
+#endif
+
+  // Reset HSI14 bit
+  RCC->CR2 &= (uint32_t)0xFFFFFFFEU;
+
+  // Disable all interrupts
+  RCC->CIR = 0x00000000U;
+}