#include <stdio.h>
 #include <stdint.h>

 #define armv6_read_ccr( val ) \
         asm volatile("mrc   p15, 0, %0, c15, c12, 1" : "=r"(val))
 #define armv6_read_cr0( val ) \
         asm volatile("mrc   p15, 0, %0, c15, c12, 2" : "=r"(val))
 #define armv6_read_cr1( val ) \
         asm volatile("mrc   p15, 0, %0, c15, c12, 3" : "=r"(val))
 #define armv6_read_pmcr( val ) \
         asm volatile("mrc   p15, 0, %0, c15, c12, 0" : "=r"(val))
 #define armv6_write_pmcr( val ) \
         asm volatile("mcr   p15, 0, %0, c15, c12, 0" : : "r"(val))

 int main( int argc, char** argv, char** envp )
 {
         uint32_t cr1;
         uint32_t before_ccr, after_ccr;
         uint32_t before_cr0, after_cr0;
         uint32_t before_cr1, after_cr1;
         unsigned int i;

         armv6_read_cr1( cr1 );
         printf("PMCR=%x\n", cr1 );

         armv6_write_pmcr( 0x00705707 );
         armv6_read_cr1( before_cr1 );
         armv6_read_ccr( before_ccr );
         armv6_read_cr0( before_cr0 );
         // Beginn auszumessende Codesequenz
         for (i=0; i<10; i++ )
                 ;
         // Ende auszumessende Codesequenz
         armv6_read_cr0( after_cr0 );
         armv6_read_ccr( after_ccr );
         armv6_read_cr1( after_cr1 );

         printf("ccr: %d (before: %d after: %d) CYCLES\n",
                 after_ccr-before_ccr, before_ccr, after_ccr);
         printf("cr0: %d (before: %d after: %d) INSTRUCTIONS\n",
                 after_cr0-before_cr0, before_cr0, after_cr0);
         printf("cr1: %d (before: %d after: %d) BRANCHES\n",
                 after_cr1-before_cr1, before_cr1, after_cr1);

         armv6_read_cr1( cr1 );
         printf("PMCR=%x\n", cr1 );
         return 0;
 }