initial

FIRMWARE/test_rdcycle.c

@@ -0,0 +1,13 @@
+#include "perf.h"
+
+int main() {
+   for(int i=0; i<100; ++i) {
+      uint64_t cycles = rdcycle();
+      uint64_t instret = rdinstret();      
+      printf("i=%d    cycles=%d     instret=%d\n", i, (int)cycles, (int)instret);
+   }
+   uint64_t instret = rdinstret();      
+   uint64_t cycles = rdcycle();
+   printf("cycles=%d     instret=%d    100CPI=%d\n", (int)cycles, (int)instret, (int)(100*cycles/instret));
+   
+}