#include <mmap.h>
/*
+ * These values are pushed on the stack just before
+ * entering the ISR. Normally, this would require
+ * assembly or inline assembly code. I use a so-called
+ * 'naked function' __attribute__ ((interrupt)) which
+ * gives me a little bit more control over the caller
+ *
+ * The following register are pushed to the stack
+ * in reverse order
+ *
+ * */
+struct interrupt_frame {
+
+ uint32_t r0; // N-32
+ uint32_t r1;
+ uint32_t r2;
+ uint32_t r3;
+ uint32_t r12;
+ uint32_t lr;
+ uint32_t pc;
+ uint32_t psr; // N-4
+};
+
+/*
* Vector table, each entry contains an interrupt
- * service routine: *
+ * service routine:
*
* interrupt vector 1-15: processor exceptions
- * interrupt vector 16-32: irq0 - irq ..
+ * interrupt vector 16-92: irq0 - irq ..
* */
-uint32_t ivt[32];
+uint32_t ivt[92];
+/* each message corresponds to each and every exception.
+ * We get the correct message by accessing
+ * exception_message[interrupt_number]
+ * exception_message[0] is not used (=MSP)*/
+
+char * exception_message(uint8_t intnr) {
+
+ char * messages[] = {
+ "--",
+ "RESET",
+ "NMI",
+ "HARD FAULT",
+ "MEMMANAGE FAULT",
+ "BUS FAULT",
+ "USAGE FAULT",
+ "RESERVED",
+ "SVC",
+ "DEBUG MONITOR",
+ "RESERVED",
+ "RESERVED",
+ "RESERVED",
+ "RESERVED",
+ "PENDSV",
+ "SYSTICK",
+ "IRQ1",
+ "IRQ2",
+ "IRQ3",
+ "IRQ4",
+ // add more if needed
+ };
+
+ if (intnr < 20) // TODO: strlen
+ return messages[intnr];
+
+ return NULL;
+}
void ivt_set_gate(unsigned char num, void * isr(), short pri) {
/* Dummy interrupt */
-void * dummy_isr() {
+// __attribute__ ((interrupt))
+void * dummy_isr(/* struct interrupt_frame * frame */) {
+ uint8_t nr = *SCB_VTOR_ST & 0xFF;
+
+ uart_puts("EXCEPTION: ");
+ uart_puts(exception_message(nr));
+ uart_puts("\nSYSTEM HALTED\n");
+
+ for(;;);
}
/* Initialize interrupt vector */
void ivt_init() {
/* clear entiry IVT, in SRAM location for SRAM + .data (in .bss section) */
- memset(&ivt, 0, (sizeof(uint32_t) * 87));
+ memset(&ivt, 0, (sizeof(uint32_t) * 92));
// stack top is loaded from the first entry table on boot/reset
// don't need to relocate or init this here
extern void * reset, * nmi, * hardfault;
- ivt_set_gate(1, dummy_isr, 0);
- ivt_set_gate(2, dummy_isr, 0);
- ivt_set_gate(3, dummy_isr, 0);
+ for (int i = 1; i <= 6 ; i++) {
+ ivt_set_gate(i, dummy_isr, 0);
+ }
/* the vector table starts at 0x0. Since the address 0x0 point to
* bootcode, it is on ROM or FLASH. The vector table can be
* relocated to other memory locations. We can do this by setting
* a register in the NVIC called the vector table offset register */
- *SCB_VTOR = (volatile uint32_t) &ivt;
+ //*SCB_VTOR = (volatile uint32_t) &ivt;
+ regw_u32(SCB_VTOR, (uint32_t) &ivt, 0, 0x01);
}