X-Git-Url: https://robinkrens.nl/gitweb/?a=blobdiff_plain;f=systick.c;h=05f515fde9be2b0f00ae4964ccc0319fc330095e;hb=d98e5505c9433565ebb71fa6a843997ea0e0cda6;hp=b9c87568f62f9a3563d6a6f5f6be491875ec3f58;hpb=2ad654f037bae2ec8f0223179c4b96c23308c34d;p=cortex-from-scratch

diff --git a/systick.c b/systick.c
index b9c8756..05f515f 100644
--- a/systick.c
+++ b/systick.c
@@ -1,28 +1,53 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <stm32.h>
-#include <mmap.h>
 
+#include <sys/robsys.h>
+#include <sys/mmap.h>
 
-void * systick_handler() {
+#include <lib/regfunc.h>
+#include <lib/stdio.h>
 
-	*RANDOM_ADDR = (volatile uint32_t) 0x10101010 ;
-}
+struct interrupt_frame {
 
-void systick_init() {
+        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
+};
+
+//__attribute__ ((interrupt))
+void * systick_handler(/* struct interrupt_frame * frame */) {
+
+//	cputs("TICKING\n");
+//	for(;;);
+}
 
-	/* Enable the counter and enable the interrupt
-	 * associated with it */
-	*STK_CTRL = (volatile uint32_t) 0x00000003;
 
-	/* The counter reload register here holds 
-	 * 0x1000 -- that's 4096 clock cycles -- if 
-	 * it is down to zero it is restores the value */
-	*STK_RELOAD = (volatile uint32_t) 0x00000400; 
+void systick_init() {
 
 	/* Every time the counter counts down to zero
 	 * a systick exception is asserted. Systick has
 	 * exception number 15. in the vector table  */
 	ivt_set_gate(15, systick_handler, 0); 
+
+	/* Get calibration and set this to 1 sec
+	 * !Most boards have a 1 ms or 10 ms 
+	 * calibration value */
+	int calib = (*STK_CALIB << 0) * 500;
+
+	/* The counter reload registers counts down to zero
+	 * and then it is restores the value */
+	rwrite(STK_RELOAD, calib);
+	
+	/* Enable the counter and enable the interrupt
+	 * associated with it */
+	rsetbit(STK_CTRL, 0);
+	rsetbit(STK_CTRL, 1);
+
+
 }