It is common to want to set a property to a nul-terminated string in a
device tree. Add python methods to handle this.
Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx>
---
Changes in v2:
- Add support for unicode strings
- Check for invalid embedded nul characters in as_str()
- Check for nul termination in as_str()
- Make the as_str() function a non-member of Property
pylibfdt/libfdt.i | 30 ++++++++++++++++++++++++++++++
tests/pylibfdt_tests.py | 27 +++++++++++++++++++++++++++
2 files changed, 57 insertions(+)
diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
index 0eefc5a..ae63263 100644
--- a/pylibfdt/libfdt.i
+++ b/pylibfdt/libfdt.i
@@ -170,6 +170,14 @@ def as_uint64(bytes):
def as_int64(bytes):
return as_cell(bytes, 'q')
+def as_str(self):
+ """Unicode is supposed by decoding from UTF-8"""
+ if self[-1] != 0:
+ raise ValueError('Property lacks nul termination')
+ if 0 in self[:-1]:
+ raise ValueError('Property contains embedded nul characters')
+ return self[:-1].decode('utf-8')
+
class Fdt:
"""Device tree class, supporting all operations
@@ -601,6 +609,28 @@ class Fdt:
return check_err(fdt_setprop_u64(self._fdt, nodeoffset, prop_name, val),
quiet)
+ def setprop_str(self, nodeoffset, prop_name, val, quiet=()):
+ """Set the string value of a property
+
+ The property is set to the string, with a nul terminator added
+
+ Args:
+ nodeoffset: Node offset containing the property to create/update
+ prop_name: Name of property
+ val: Value to write (string without nul terminator). Unicode is
+ supposed by encoding to UTF-8
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Returns:
+ Error code, or 0 if OK
+
+ Raises:
+ FdtException if no parent found or other error occurs
+ """
+ val = (val + '\0').encode('utf-8')
+ return check_err(fdt_setprop(self._fdt, nodeoffset, prop_name,
+ val, len(val)), quiet)
+
def delprop(self, nodeoffset, prop_name):
"""Delete a property from a node
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index 2badef2..738210f 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -68,6 +68,8 @@ TEST_VALUE64_1L = 0x01abcdef
TEST_VALUE64_1 = (TEST_VALUE64_1H << 32) | TEST_VALUE64_1L
TEST_STRING_1 = 'hello world'
+TEST_STRING_2 = 'hi world'
+TEST_STRING_3 = u'unicode ' + unichr(467)
def get_err(err_code):
@@ -441,6 +443,31 @@ class PyLibfdtTests(unittest.TestCase):
self.assertEquals(struct.pack('>Q', TEST_VALUE64_1),
self.fdt.getprop(node, prop))
+ def testSetPropStr(self):
+ """Test that we can set a property to a particular string"""
+ node = 0
+ prop = 'prop-str'
+ self.assertEquals(TEST_STRING_1,
+ libfdt.as_str(self.fdt.getprop(node, prop)))
+ self.fdt.setprop_str(node, prop, TEST_STRING_2)
+ self.assertEquals(TEST_STRING_2,
+ libfdt.as_str(self.fdt.getprop(node, prop)))
+ with self.assertRaises(ValueError) as e:
+ libfdt.as_str(self.fdt.getprop(node, 'prop-int'))
+ self.assertIn('lacks nul termination', str(e.exception))
+
+ node2 = self.fdt.path_offset('/subnode@1/subsubnode')
+ with self.assertRaises(ValueError) as e:
+ libfdt.as_str(self.fdt.getprop(node2, 'compatible'))
+ self.assertIn('embedded nul', str(e.exception))
+
+ # Expand the device tree so we now have room
+ self.fdt.resize(self.fdt.totalsize() + 50)
+ prop = 'prop-unicode'
+ self.fdt.setprop_str(node, prop, TEST_STRING_3)
+ self.assertEquals(TEST_STRING_3,
+ libfdt.as_str(self.fdt.getprop(node, prop)))
+
if __name__ == "__main__":
unittest.main()
--
2.17.1.1185.g55be947832-goog
--
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