Add prelude code for mockup

files/mockup_prelude.cc

+#include "os.h"
+#include "test/test.h"
+#include "machine.h"
+#include <stdio.h>
+
+void os_main(void) {
+        StartOS(0);
+}
+
+void PreIdleHook() {
+        ShutdownMachine();
+}
+
+int _decisionMaker(int i) {
+	printf("Decision %d: ", i);
+	int res = (getchar() == '0') ? 0 : 1;
+
+	getchar(); // newline
+
+	return res;
+}
+
+extern "C" {
+extern const uint32_t _sdata_os_canonical, _edata_os_canonical;
+extern const uint32_t _sdata_arch_canonical, _edata_arch_canonical;
+}
+
+// **********************************************************************
+// Murmur3 implementation
+//
+// See https://en.wikipedia.org/wiki/MurmurHash and
+// http://programmers.stackexchange.com/a/145633
+//
+// Adapted almost literally from:
+// https://github.com/aappleby/smhasher/blob/61a0530f28277f2e850bfc39600ce61d02b518de/src/MurmurHash3.cpp
+// **********************************************************************
+#define ROTL32(x, y) ((x << y) | (x >> (32 - y)))
+
+uint32_t murmur3_32(const char *key, uint32_t len, uint32_t seed) {
+    const uint8_t *data = (const uint8_t*)key;
+    const int nblocks = len / 4;
+
+    uint32_t h1 = seed;
+
+    const uint32_t c1 = 0xcc9e2d51;
+    const uint32_t c2 = 0x1b873593;
+
+    // body
+
+    const uint32_t *blocks = (const uint32_t*)(data + nblocks*4);
+
+    for (int i = -nblocks; i < 0; i++) {
+        uint32_t k1 = blocks[i];
+
+        k1 *= c1;
+        k1 = ROTL32(k1, 15);
+        k1 *= c2;
+
+        h1 ^= k1;
+        h1 = ROTL32(h1, 13);
+        h1 = h1*5+0xe6546b64;
+    }
+
+    // tail
+
+    const uint8_t *tail = (const uint8_t*)(data + nblocks*4);
+
+    uint32_t k1 = 0;
+
+    switch (len & 3) {
+    case 3:
+        k1 ^= tail[2] << 16;
+        // intentional fallthrough
+    case 2:
+        k1 ^= tail[1] << 8;
+        // intentional fallthrough
+    case 1:
+        k1 ^= tail[0];
+        k1 *= c1;
+        k1 = ROTL32(k1, 15);
+        k1 *= c2;
+        h1 ^= k1;
+    }
+
+    // finalization
+
+    h1 ^= len;
+
+    h1 ^= h1 >> 16;
+    h1 *= 0x85ebca6b;
+    h1 ^= h1 >> 13;
+    h1 *= 0xc2b2ae35;
+    h1 ^= h1 >> 16;
+
+    return h1;
+}
+
+// **********************************************************************
+// End Murmur3
+// **********************************************************************
+
+uint32_t hash_os_state() {
+    const char *start = (const char*)&_sdata_os_canonical;
+    const char *end = (const char*)&_edata_os_canonical;
+    uint32_t len = end-start;
+    uint32_t seed = 0; // be deterministic
+
+    uint32_t first_hash = murmur3_32(start, len, seed);
+
+    start = (const char*)&_sdata_arch_canonical;
+    end = (const char*)&_edata_arch_canonical;
+    len = end - start;
+
+    uint32_t second_hash = murmur3_32(start, len, seed);
+
+    return first_hash ^ second_hash;
+}
+
+void _print_os_state(int line) {
+	kout << "Line " << line << " in state ";
+	kout << "0x" << hex << hash_os_state() << dec << endl;
+}