binman: Add a test to catch use of the old 'pos' property

This property has been changed to 'offset'. To help downstream users who
might still be using 'pos', add a check that this is not used by mistake.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index 6ce5dbd..77cfab9 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -143,6 +143,8 @@
 
         This reads all the fields we recognise from the node, ready for use.
         """
+        if 'pos' in self._node.props:
+            self.Raise("Please use 'offset' instead of 'pos'")
         self.offset = fdt_util.GetInt(self._node, 'offset')
         self.size = fdt_util.GetInt(self._node, 'size')
         self.align = fdt_util.GetInt(self._node, 'align')
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index ce473df..3d5f235 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -1361,6 +1361,13 @@
         data = self._DoReadFile('78_u_boot_tpl.dts')
         self.assertEqual(U_BOOT_TPL_DATA + U_BOOT_TPL_DTB_DATA, data)
 
+    def testUsesPos(self):
+        """Test that the 'pos' property cannot be used anymore"""
+        with self.assertRaises(ValueError) as e:
+           data = self._DoReadFile('79_uses_pos.dts')
+        self.assertIn("Node '/binman/u-boot': Please use 'offset' instead of "
+                      "'pos'", str(e.exception))
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/tools/binman/test/79_uses_pos.dts b/tools/binman/test/79_uses_pos.dts
new file mode 100644
index 0000000..7638b9b
--- /dev/null
+++ b/tools/binman/test/79_uses_pos.dts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
+/dts-v1/;
+
+/ {
+	binman {
+		u-boot {
+			pos = <10>;
+		};
+	};
+};