diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py index e7703c1..9d69b42 100644 --- a/tools/dtoc/fdt.py +++ b/tools/dtoc/fdt.py @@ -270,6 +270,33 @@ class Node: del self.props[prop_name] self._fdt.Invalidate() + def AddZeroProp(self, prop_name): + """Add a new property to the device tree with an integer value of 0. + + Args: + prop_name: Name of property + """ + fdt_obj = self._fdt._fdt_obj + if fdt_obj.setprop_u32(self.Offset(), prop_name, 0, + (libfdt.NOSPACE,)) == -libfdt.NOSPACE: + fdt_obj.open_into(fdt_obj.totalsize() + 1024) + fdt_obj.setprop_u32(self.Offset(), prop_name, 0) + self.props[prop_name] = Prop(self, -1, prop_name, '\0' * 4) + self._fdt.Invalidate() + + def SetInt(self, prop_name, val): + """Update an integer property int the device tree. + + This is not allowed to change the size of the FDT. + + Args: + prop_name: Name of property + val: Value to set + """ + fdt_obj = self._fdt._fdt_obj + fdt_obj.setprop_u32(self.Offset(), prop_name, val) + + class Fdt: """Provides simple access to a flat device tree blob using libfdts. diff --git a/tools/dtoc/test_fdt.py b/tools/dtoc/test_fdt.py index 49d188b..f085b1d 100755 --- a/tools/dtoc/test_fdt.py +++ b/tools/dtoc/test_fdt.py @@ -319,6 +319,26 @@ class TestProp(unittest.TestCase): self.assertTrue(isinstance(prop.value, list)) self.assertEqual(3, len(prop.value)) + def testAdd(self): + """Test adding properties""" + self.fdt.pack() + # This function should automatically expand the device tree + self.node.AddZeroProp('one') + self.node.AddZeroProp('two') + self.node.AddZeroProp('three') + + # Updating existing properties should be OK, since the device-tree size + # does not change + self.fdt.pack() + self.node.SetInt('one', 1) + self.node.SetInt('two', 2) + self.node.SetInt('three', 3) + + # This should fail since it would need to increase the device-tree size + with self.assertRaises(libfdt.FdtException) as e: + self.node.SetInt('four', 4) + self.assertIn('FDT_ERR_NOSPACE', str(e.exception)) + class TestFdtUtil(unittest.TestCase): """Tests for the fdt_util module