tests: add oraclebp mmio test (#31)

tests/oracletest/Makefile

+NAME := oracletest
+SRCS := $(shell find -L ./src/ -name "*.[cS]")
+
+include $(AM_HOME)/Makefile.app

tests/oracletest/README.md

+# OracleBP Test
+
+## Purpose
+
+A fully functional OracleBP should predict well even after some unpredictable events like interrupt and MMIO accessing happen. This test wants to verify if the oracle predictor still works after a MMIO access that affects the control flow.
+
+## Verification
+
+Change final loop iteration count to see if there are too many mispredictions.
\ No newline at end of file

tests/oracletest/include/test.h

+#ifndef __AMUNIT_H__
+#define __AMUNIT_H__
+
+#include <am.h>
+#include <klib.h>
+#include <klib-macros.h>
+
+#endif

tests/oracletest/src/main.c

+#include <test.h>
+
+#if defined(__ARCH_RISCV64_NOOP) || defined(__ARCH_RISCV32_NOOP) || defined(__ARCH_RISCV64_XS)
+# define RTC_ADDR     0x3800bff8
+#endif
+
+#define TESTDUP 100
+#define FINALITERATION 8000
+
+volatile int counter;
+
+void loop(int n) {
+    for (volatile int i = 0; i < n; i++) {
+        counter += 1;
+    }
+}
+
+uint64_t get_time() {
+    return *(uint64_t *)(RTC_ADDR);
+}
+
+int main() {
+    printf("Oracle BP test shall always pass\n");
+    printf("Check perf counter for OracleBP correctness\n");
+    
+    for (int i = 0; i < TESTDUP; i++) {
+        int a = get_time() % 10;
+        switch (a)
+        {
+        case 0:
+            loop(5);
+            break;
+        case 1:
+            loop(10);
+            break;
+        case 2:
+            loop(15);
+            break;
+        case 3:
+            loop(20);
+            break;
+        case 4:
+            loop(25);
+            break;
+        case 5:
+            loop(30);
+            break;
+        case 6:
+            loop(35);
+            break;
+        case 7:
+            loop(40);
+            break;
+        case 8:
+            loop(45);
+            break;
+        case 9:
+            loop(50);
+            break;
+        default:
+            printf("Should not reach here! Check your test environment\n");
+            break;
+        }
+    }
+
+    for (volatile int i = 0; i < FINALITERATION; i++) {
+        counter += i;
+    }
+
+    return 0;
+}