ReadBytes function in AMemory, with cleaner range check. (#136)

Memory/AMemory.cs

@@ -301,6 +301,15 @@ namespace ChocolArm64.Memory
             return *((ulong*)(RamPtr + (uint)Position));
         }
 
+        public byte[] ReadBytes(long Position, long Size)
+        {
+            EnsureRangeIsValid(Position, Size, AMemoryPerm.Read);
+
+            byte[] Result = new byte[Size];
+            Marshal.Copy((IntPtr)(RamPtr + (uint)Position), Result, 0, (int)Size);
+            return Result;
+        }
+
         public Vector128<float> ReadVector8Unchecked(long Position)
         {
             if (Sse2.IsSupported)
@@ -611,6 +620,17 @@ namespace ChocolArm64.Memory
             }
         }
 
+        private void EnsureRangeIsValid(long Position, long Size, AMemoryPerm Perm)
+        {
+            long EndPos = (Position + Size);
+            Position = Position & ~AMemoryMgr.PageMask; //check base of each page
+            while (Position < EndPos)
+            {
+                EnsureAccessIsValid(Position, Perm);
+                Position += AMemoryMgr.PageSize;
+            }
+        }
+
         public void Dispose()
         {
             Dispose(true);

Memory/AMemoryHelper.cs

@@ -22,18 +22,6 @@ namespace ChocolArm64.Memory
             }
         }
 
-        public static byte[] ReadBytes(AMemory Memory, long Position, long Size)
-        {
-            byte[] Data = new byte[Size];
-
-            for (long Offs = 0; Offs < Size; Offs++)
-            {
-                Data[Offs] = (byte)Memory.ReadByte(Position + Offs);
-            }
-
-            return Data;
-        }
-
         public static void WriteBytes(AMemory Memory, long Position, byte[] Data)
         {
             for (int Offs = 0; Offs < Data.Length; Offs++)