+/* (CC-BY-NC-SA) ROBIN KRENS - ROBIN @ ROBINKRENS.NL
+ *
+ * $LOG$
+ * 2019/7/20 - ROBIN KRENS
+ * Initial version
+ *
+ * $DESCRIPTION$
+ * Set up of basic exceptions and interrupts. These interrupts
+ * don't do much, except for halting the system.
+ * ivt_set_gate(interrupt nr, function, priority) can be used
+ * later to define more appropriate handling. See timer (timer.c)
+ * or serial or (uart.c) handling for non-trivial examples.
+ *
+ * The actual code is not much, but there are a lot of details
+ * to consider. Besides that, in case more control is desired over
+ * entering and exiting interrupts (what is pushed on the stack)
+ * A so-called naked function can be used. See below for more
+ * details.
+ *
+ *
+ * */
+
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
-#include <stm32.h>
-#include <mmap.h>
+
+#include <sys/robsys.h>
+#include <sys/mmap.h>
+
+#include <lib/stdio.h>
+#include <lib/string.h>
+#include <lib/regfunc.h>
/*
* These values are pushed on the stack just before
* gives me a little bit more control over the caller
*
* The following register are pushed to the stack
- * in reverse order
+ * in reverse order:
*
* */
struct interrupt_frame {
* service routine:
*
* interrupt vector 1-15: processor exceptions
- * interrupt vector 16-64: irq0 - irq ..
+ * interrupt vector 16-92: irq0 - irq ..
+ *
+ * Vector table needs to be aligned in memory.
* */
-uint32_t ivt[64];
+uint32_t __attribute__((aligned(0x100))) 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)*/
-unsigned char *exception_messages[] =
-{
- "--",
- "RESET",
- "NMI",
- "HARD FAULT",
- "MEMMANAGE FAULT",
- "BUS FAULT",
- "USAGE FAULT",
- "RESERVED",
- "SVC",
- "DEBUG MONITOR",
- "RESERVED",
- "PENDSV",
- "SYSTICK",
- "IRQ1",
- "IRQ2",
- "IRQ3",
- "IRQ4",
- // add more if needed
-};
+
+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 */
-__attribute__ ((interrupt))
-void * dummy_isr(struct interrupt_frame * frame) {
-
+/* Dummy interrupt: comment out the comment to use a naked f
+ * function */
- uint32_t * p = (volatile uint32_t *) 0x21000000;
+// __attribute__ ((interrupt))
+void * dummy_isr(/* struct interrupt_frame * frame */) {
- addrtohex(frame->r0);
- addrtohex(frame->r1);
- addrtohex(frame->r2);
- addrtohex(frame->r3);
- addrtohex(frame->r12);
- addrtohex(frame->lr);
- addrtohex(frame->pc);
- addrtohex(frame->psr);
+ uint8_t nr = *SCB_VTOR_ST & 0xFF;
- //__asm__ __volatile__ ("MRS r0, IPSR");
- //addrtohex(frame->r0);
- uart_puts("EXCEPTION X: SYSTEM HALTED\n");
+ cputs("EXCEPTION: ");
+ cputs(exception_message(nr));
+ cputs("\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));
+ /* clear entire IVT, in SRAM location for SRAM + .data (in .bss section) */
+ 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;
- for (int i = 1; i < 7; i++) {
+ for (int i = 1; i <= 64 ; 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
+ /* The vector table is intially at 0x0. 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;
- regw_u32(SCB_VTOR, (uint32_t) &ivt, 0, 0x01);
+ regw_u32(SCB_VTOR, (uint32_t) &ivt, 0, OWRITE);
}