implement cu_memtest for cheacking if memory is zeroed

cutil.c

@@ -24,3 +24,21 @@ void cutil_init()
 void cutil_exit()
 {
 }
+
+const void* cu_memtest(const void* mem, uint size)
+{
+    unsigned i;
+    for (i = 0; i < size / sizeof(uword); i++)
+    {
+        if (*(uword*)mem) return mem;
+        *(uword*)mem++;
+    }
+
+    for (i = 0; i < size % sizeof(uword); i++)
+    {
+        if (*(uint8_t*)mem) return mem;
+        *(uint8_t*)mem++;
+    }
+
+    return NULL;
+}

cutil.h

@@ -21,4 +21,6 @@ extern void* (*cu_memmove)(void*,const void*,size_t);
 void cutil_init();
 void cutil_exit();
 
+const void* cu_memtest(const void* mem, uint size);
+
 #endif

test.c

@@ -101,6 +101,10 @@ int main()
 
     printf("[cutil]\n");
     printf("cutil_arch\t%u\n", CU_ARCH);
+    uint64_t val1 = 0;
+    printf("val1\t%u\tcu_memtest\t%p\n", val1, cu_memtest(&val1, sizeof(val1)));
+    char val2[] = {0,0,0,1,0,0,0,0,0,0,4,0,0};
+    printf("val2\tcu_memtest\t%p\n", cu_memtest(val2, sizeof(val2)));
 
     printf("[endian]\n");
     printf("cutil_endian\t%u\n", cu_endian);