Start clock on F0 and F0, and handle USB interrupts.

hw/bsp/stm32f070rbnucleo/board.mk

@@ -3,7 +3,7 @@ CFLAGS += \
 	-DSTM32F070xB \
 	-mthumb \
 	-mabi=aapcs-linux \
-	-mcpu=cortex-m4 \
+	-mcpu=cortex-m0 \
 	-mfloat-abi=soft \
 	-nostdlib -nostartfiles \
 	-DCFG_TUSB_MCU=OPT_MCU_STM32_FSDEV

hw/bsp/stm32f070rbnucleo/stm32f070rbnucleo.c

@@ -91,6 +91,14 @@ void board_init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
+  // Start USB clock
+  __HAL_RCC_USB_CLK_ENABLE();
+}
+
+void dcd_fs_irqHandler(void);
+void USB_IRQHandler(void)
+{
+	dcd_fs_irqHandler();
 }
 
 //--------------------------------------------------------------------+

hw/bsp/stm32f303disco/stm32f303disco.c

@@ -86,6 +86,10 @@ void board_init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
+
+  // Start USB clock
+  __HAL_RCC_USB_CLK_ENABLE();
+
 #if 0
   RCC->AHB2ENR |= RCC_AHB2ENR_OTGFSEN;
 
@@ -105,6 +109,31 @@ void board_init(void)
 #endif
 }
 
+// USB defaults to using interrupts 19, 20, and 42 (based on SYSCFG_CFGR1.USB_IT_RMP)
+// FIXME: Do all three need to be handled, or just the LP one?
+void dcd_fs_irqHandler(void);
+// USB high-priority interrupt (Channel 19): Triggered only by a correct
+// transfer event for isochronous and double-buffer bulk transfer to reach
+// the highest possible transfer rate.
+void USB_HP_CAN_TX_IRQHandler(void)
+{
+	dcd_fs_irqHandler();
+}
+
+// USB low-priority interrupt (Channel 20): Triggered by all USB events
+// (Correct transfer, USB reset, etc.). The firmware has to check the
+// interrupt source before serving the interrupt.
+void USB_LP_CAN_RX0_IRQHandler(void)
+{
+	dcd_fs_irqHandler();
+}
+// USB wakeup interrupt (Channel 42): Triggered by the wakeup event from the USB
+// Suspend mode.
+void USBWakeUp_IRQHandler(void)
+{
+	dcd_fs_irqHandler();
+}
+
 //--------------------------------------------------------------------+
 // Board porting API
 //--------------------------------------------------------------------+