utils: Add unit tests for util.rs

src/utils/util.rs

@@ -46,3 +46,46 @@ pub fn zero_mem_region(start: VirtAddr, end: VirtAddr) {
     // Zero region
     unsafe { start.as_mut_ptr::<u8>().write_bytes(0, size) }
 }
+
+#[cfg(test)]
+mod tests {
+
+    use crate::utils::util::*;
+
+    #[test]
+    fn test_mem_utils() {
+        // Align up
+        assert_eq!(align_up(7, 4), 8);
+        assert_eq!(align_up(15, 8), 16);
+        assert_eq!(align_up(10, 2), 10);
+        // Align down
+        assert_eq!(align_down(7, 4), 4);
+        assert_eq!(align_down(15, 8), 8);
+        assert_eq!(align_down(10, 2), 10);
+        // Page align up
+        assert_eq!(page_align_up(4096), 4096);
+        assert_eq!(page_align_up(4097), 8192);
+        assert_eq!(page_align_up(0), 0);
+        // Page offset
+        assert_eq!(page_offset(4096), 0);
+        assert_eq!(page_offset(4097), 1);
+        assert_eq!(page_offset(0), 0);
+        // Overlaps
+        assert!(overlap(1, 5, 3, 6));
+        assert!(overlap(0, 10, 5, 15));
+        assert!(!overlap(1, 5, 6, 8));
+    }
+
+    #[test]
+    fn test_zero_mem_region() {
+        let mut data: [u8; 10] = [1; 10];
+        let start = VirtAddr::new(&mut data[0] as *mut u8 as usize);
+        let end = start + 10;
+
+        zero_mem_region(start, end);
+
+        for byte in &data {
+            assert_eq!(*byte, 0);
+        }
+    }
+}