efm32: make all interrupts usable in vector table

* define weak symbol for ${irq_name}_isr
* put them in the rom vector table
* declare reset_vector weak in case someone wants to insert code there
* remove null_handler (null handlers should be only requested
  explicitly, and finding out why the chip gets stuck is easier than
  determining whether or not a no-op interrupt handler was executed)

lib/efm32/tinygecko/vector.c

@@ -18,6 +18,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <libopencm3/efm32/tinygecko/irq.h>
 #include <libopencm3/efm32/vector.h>
 
 #define WEAK __attribute__ ((weak))
@@ -26,10 +27,9 @@
 extern unsigned _etext, _data, _edata, _ebss, _stack;
 
 void main(void);
-void reset_handler(void);
 void blocking_handler(void);
-void null_handler(void);
 
+void WEAK reset_handler(void);
 void WEAK nmi_handler(void);
 void WEAK hard_fault_handler(void);
 void WEAK mem_manage_handler(void);
@@ -40,6 +40,29 @@ void WEAK debug_monitor_handler(void);
 void WEAK pend_sv_handler(void);
 void WEAK sys_tick_handler(void);
 
+void WEAK dma_isr(void);
+void WEAK gpio_even_isr(void);
+void WEAK timer0_isr(void);
+void WEAK usart0_rx_isr(void);
+void WEAK usart0_tx_isr(void);
+void WEAK acmp01_isr(void);
+void WEAK adc0_isr(void);
+void WEAK dac0_isr(void);
+void WEAK i2c0_isr(void);
+void WEAK gpio_odd_isr(void);
+void WEAK timer1_isr(void);
+void WEAK usart1_rx_isr(void);
+void WEAK usart1_tx_isr(void);
+void WEAK lesense_isr(void);
+void WEAK leuart0_isr(void);
+void WEAK letimer0_isr(void);
+void WEAK pcnt0_isr(void);
+void WEAK rtc_isr(void);
+void WEAK cmu_isr(void);
+void WEAK vcmp_isr(void);
+void WEAK lcd_isr(void);
+void WEAK msc_isr(void);
+void WEAK aes_isr(void);
 
 __attribute__ ((section(".vectors")))
 efm32_vector_table_t vector_table = {
@@ -53,9 +76,34 @@ efm32_vector_table_t vector_table = {
 	.sv_call = sv_call_handler,
 	.pend_sv = pend_sv_handler,
 	.systick = sys_tick_handler,
+	.irq = {
+		[IRQ_DMA] = dma_isr,
+		[IRQ_GPIO_EVEN] = gpio_even_isr,
+		[IRQ_TIMER0] = timer0_isr,
+		[IRQ_USART0_RX] = usart0_rx_isr,
+		[IRQ_USART0_TX] = usart0_tx_isr,
+		[IRQ_ACMP01] = acmp01_isr,
+		[IRQ_ADC0] = adc0_isr,
+		[IRQ_DAC0] = dac0_isr,
+		[IRQ_I2C0] = i2c0_isr,
+		[IRQ_GPIO_ODD] = gpio_odd_isr,
+		[IRQ_TIMER1] = timer1_isr,
+		[IRQ_USART1_RX] = usart1_rx_isr,
+		[IRQ_USART1_TX] = usart1_tx_isr,
+		[IRQ_LESENSE] = lesense_isr,
+		[IRQ_LEUART0] = leuart0_isr,
+		[IRQ_LETIMER0] = letimer0_isr,
+		[IRQ_PCNT0] = pcnt0_isr,
+		[IRQ_RTC] = rtc_isr,
+		[IRQ_CMU] = cmu_isr,
+		[IRQ_VCMP] = vcmp_isr,
+		[IRQ_LCD] = lcd_isr,
+		[IRQ_MSC] = msc_isr,
+		[IRQ_AES] = aes_isr,
+	}
 };
 
-void reset_handler(void)
+void WEAK reset_handler(void)
 {
 	volatile unsigned *src, *dest;
 
@@ -76,17 +124,36 @@ void blocking_handler(void)
 	while (1) ;
 }
 
-void null_handler(void)
-{
-	/* Do nothing. */
-}
-
-#pragma weak nmi_handler = null_handler
+#pragma weak nmi_handler = blocking_handler
 #pragma weak hard_fault_handler = blocking_handler
 #pragma weak mem_manage_handler = blocking_handler
 #pragma weak bus_fault_handler = blocking_handler
 #pragma weak usage_fault_handler = blocking_handler
-#pragma weak sv_call_handler = null_handler
-#pragma weak debug_monitor_handler = null_handler
-#pragma weak pend_sv_handler = null_handler
-#pragma weak sys_tick_handler = null_handler
+#pragma weak sv_call_handler = blocking_handler
+#pragma weak debug_monitor_handler = blocking_handler
+#pragma weak pend_sv_handler = blocking_handler
+#pragma weak sys_tick_handler = blocking_handler
+
+#pragma weak dma_isr = blocking_handler
+#pragma weak gpio_even_isr = blocking_handler
+#pragma weak timer0_isr = blocking_handler
+#pragma weak usart0_rx_isr = blocking_handler
+#pragma weak usart0_tx_isr = blocking_handler
+#pragma weak acmp01_isr = blocking_handler
+#pragma weak adc0_isr = blocking_handler
+#pragma weak dac0_isr = blocking_handler
+#pragma weak i2c0_isr = blocking_handler
+#pragma weak gpio_odd_isr = blocking_handler
+#pragma weak timer1_isr = blocking_handler
+#pragma weak usart1_rx_isr = blocking_handler
+#pragma weak usart1_tx_isr = blocking_handler
+#pragma weak lesense_isr = blocking_handler
+#pragma weak leuart0_isr = blocking_handler
+#pragma weak letimer0_isr = blocking_handler
+#pragma weak pcnt0_isr = blocking_handler
+#pragma weak rtc_isr = blocking_handler
+#pragma weak cmu_isr = blocking_handler
+#pragma weak vcmp_isr = blocking_handler
+#pragma weak lcd_isr = blocking_handler
+#pragma weak msc_isr = blocking_handler
+#pragma weak aes_isr = blocking_handler