/*   
 *    *  hello.c ­ The simplest kernel module. 
 *     */ 
#include <stdio.h>

#define ARMV7_PMNC_E		(1 << 0) /* Enable all counters */
#define ARMV7_PMNC_P		(1 << 1) /* Reset all counters */
#define ARMV7_PMNC_C		(1 << 2) /* Cycle counter reset */
#define ARMV7_PMNC_D		(1 << 3) /* CCNT counts every 64th cpu cycle */
#define ARMV7_PMNC_X		(1 << 4) /* Export to ETM */
#define ARMV7_PMNC_DP		(1 << 5) /* Disable CCNT if non-invasive debug*/
#define	ARMV7_PMNC_N_SHIFT	11	 /* Number of counters supported */
#define	ARMV7_PMNC_N_MASK	0x1f
#define	ARMV7_PMNC_MASK		0x3f	 /* Mask for writable bits */

/*101b9173
static u32 armv7_pmnc_read(void)
{
	u32 val;
	asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r"(val));
	return val;
}

static void armv7_pmnc_write(u32 val)
{
	val &= ARMV7_PMNC_MASK;
	isb();
	asm volatile("mcr p15, 0, %0, c9, c12, 0" :: "r"(val));
}
*/

static void dummy()
{
}

int main() 
{ 
	unsigned int regr;
	unsigned int i;
	unsigned int a, b;

	printf("CSE237A: Hello world.\n"); 
	asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (regr));
	printf("regr: %x\n", regr);

	for (i = 0; i < 10; i++) {
		asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (a));
		asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (b));
		printf("c[%u]: %u\n", i, b - a);
	}


	return 1; 
}