1# pylibfdt - Tests for Flat Device Tree manipulation in Python
2# Copyright (C) 2017 Google, Inc.
3# Written by Simon Glass <sjg@chromium.org>
4#
5# libfdt is dual licensed: you can use it either under the terms of
6# the GPL, or the BSD license, at your option.
7#
8#  a) This library is free software; you can redistribute it and/or
9#     modify it under the terms of the GNU General Public License as
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12#
13#     This library is distributed in the hope that it will be useful,
14#     but WITHOUT ANY WARRANTY; without even the implied warranty of
15#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16#     GNU General Public License for more details.
17#
18#     You should have received a copy of the GNU General Public
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51
52import sys
53import types
54import unittest
55
56sys.path.append('../pylibfdt')
57import libfdt
58from libfdt import FdtException, QUIET_NOTFOUND, QUIET_ALL
59
60def get_err(err_code):
61    """Convert an error code into an error message
62
63    Args:
64        err_code: Error code value (FDT_ERR_...)
65
66    Returns:
67        String error code
68    """
69    return 'pylibfdt error %d: %s' % (-err_code, libfdt.fdt_strerror(-err_code))
70
71def _ReadFdt(fname):
72    """Read a device tree file into an Fdt object, ready for use
73
74    Args:
75        fname: Filename to read from
76
77    Returns:
78        Fdt bytearray suitable for passing to libfdt functions
79    """
80    return libfdt.Fdt(open(fname).read())
81
82class PyLibfdtTests(unittest.TestCase):
83    """Test class for pylibfdt
84
85    Properties:
86        fdt: Device tree file used for testing
87    """
88
89    def setUp(self):
90        """Read in the device tree we use for testing"""
91        self.fdt = _ReadFdt('test_tree1.dtb')
92
93    def GetPropList(self, node_path):
94        """Read a list of properties from a node
95
96        Args:
97            node_path: Full path to node, e.g. '/subnode@1/subsubnode'
98
99        Returns:
100            List of property names for that node, e.g. ['compatible', 'reg']
101        """
102        prop_list = []
103        node = self.fdt.path_offset(node_path)
104        poffset = self.fdt.first_property_offset(node, QUIET_NOTFOUND)
105        while poffset > 0:
106            prop = self.fdt.get_property_by_offset(poffset)
107            prop_list.append(prop.name)
108            poffset = self.fdt.next_property_offset(poffset, QUIET_NOTFOUND)
109        return prop_list
110
111    def testImport(self):
112        """Check that we can import the library correctly"""
113        self.assertEquals(type(libfdt), types.ModuleType)
114
115    def testBadFdt(self):
116        """Check that a filename provided accidentally is not accepted"""
117        with self.assertRaises(FdtException) as e:
118            fdt = libfdt.Fdt('a string')
119        self.assertEquals(e.exception.err, -libfdt.BADMAGIC)
120
121    def testPathOffset(self):
122        """Check that we can find the offset of a node"""
123        self.assertEquals(self.fdt.path_offset('/'), 0)
124        self.assertTrue(self.fdt.path_offset('/subnode@1') > 0)
125        with self.assertRaises(FdtException) as e:
126            self.fdt.path_offset('/wibble')
127        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
128        self.assertEquals(self.fdt.path_offset('/wibble', QUIET_NOTFOUND),
129                          -libfdt.NOTFOUND)
130
131    def testPropertyOffset(self):
132        """Walk through all the properties in the root node"""
133        offset = self.fdt.first_property_offset(0)
134        self.assertTrue(offset > 0)
135        for i in range(5):
136            next_offset = self.fdt.next_property_offset(offset)
137            self.assertTrue(next_offset > offset)
138            offset = next_offset
139        self.assertEquals(self.fdt.next_property_offset(offset, QUIET_NOTFOUND),
140                          -libfdt.NOTFOUND)
141
142    def testPropertyOffsetExceptions(self):
143        """Check that exceptions are raised as expected"""
144        with self.assertRaises(FdtException) as e:
145            self.fdt.first_property_offset(107)
146        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
147
148        # Quieten the NOTFOUND exception and check that a BADOFFSET
149        # exception is still raised.
150        with self.assertRaises(FdtException) as e:
151            self.fdt.first_property_offset(107, QUIET_NOTFOUND)
152        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
153        with self.assertRaises(FdtException) as e:
154            self.fdt.next_property_offset(107, QUIET_NOTFOUND)
155        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
156
157        # Check that NOTFOUND can be quietened.
158        node = self.fdt.path_offset('/subnode@1/ss1')
159        self.assertEquals(self.fdt.first_property_offset(node, QUIET_NOTFOUND),
160                          -libfdt.NOTFOUND)
161        with self.assertRaises(FdtException) as e:
162            self.fdt.first_property_offset(node)
163        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
164
165    def testGetName(self):
166        """Check that we can get the name of a node"""
167        self.assertEquals(self.fdt.get_name(0), '')
168        node = self.fdt.path_offset('/subnode@1/subsubnode')
169        self.assertEquals(self.fdt.get_name(node), 'subsubnode')
170
171        with self.assertRaises(FdtException) as e:
172            self.fdt.get_name(-2)
173        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
174
175    def testGetPropertyByOffset(self):
176        """Check that we can read the name and contents of a property"""
177        root = 0
178        poffset = self.fdt.first_property_offset(root)
179        prop = self.fdt.get_property_by_offset(poffset)
180        self.assertEquals(prop.name, 'compatible')
181        self.assertEquals(prop.value, 'test_tree1\0')
182
183        with self.assertRaises(FdtException) as e:
184            self.fdt.get_property_by_offset(-2)
185        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
186        self.assertEquals(
187                -libfdt.BADOFFSET,
188                self.fdt.get_property_by_offset(-2, [libfdt.BADOFFSET]))
189
190    def testGetProp(self):
191        """Check that we can read the contents of a property by name"""
192        root = self.fdt.path_offset('/')
193        value = self.fdt.getprop(root, "compatible")
194        self.assertEquals(value, 'test_tree1\0')
195        self.assertEquals(-libfdt.NOTFOUND, self.fdt.getprop(root, 'missing',
196                                                             QUIET_NOTFOUND))
197
198        with self.assertRaises(FdtException) as e:
199            self.fdt.getprop(root, 'missing')
200        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
201
202        node = self.fdt.path_offset('/subnode@1/subsubnode')
203        value = self.fdt.getprop(node, "compatible")
204        self.assertEquals(value, 'subsubnode1\0subsubnode\0')
205
206    def testStrError(self):
207        """Check that we can get an error string"""
208        self.assertEquals(libfdt.strerror(-libfdt.NOTFOUND),
209                          'FDT_ERR_NOTFOUND')
210
211    def testFirstNextSubnodeOffset(self):
212        """Check that we can walk through subnodes"""
213        node_list = []
214        node = self.fdt.first_subnode(0, QUIET_NOTFOUND)
215        while node >= 0:
216            node_list.append(self.fdt.get_name(node))
217            node = self.fdt.next_subnode(node, QUIET_NOTFOUND)
218        self.assertEquals(node_list, ['subnode@1', 'subnode@2'])
219
220    def testFirstNextSubnodeOffsetExceptions(self):
221        """Check except handling for first/next subnode functions"""
222        node = self.fdt.path_offset('/subnode@1/subsubnode', QUIET_NOTFOUND)
223        self.assertEquals(self.fdt.first_subnode(node, QUIET_NOTFOUND),
224                          -libfdt.NOTFOUND)
225        with self.assertRaises(FdtException) as e:
226            self.fdt.first_subnode(node)
227        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
228
229        node = self.fdt.path_offset('/subnode@1/ss1', QUIET_NOTFOUND)
230        self.assertEquals(self.fdt.next_subnode(node, QUIET_NOTFOUND),
231                          -libfdt.NOTFOUND)
232        with self.assertRaises(FdtException) as e:
233            self.fdt.next_subnode(node)
234        self.assertEquals(e.exception.err, -libfdt.NOTFOUND)
235
236    def testDeleteProperty(self):
237        """Test that we can delete a property"""
238        node_name = '/subnode@1'
239        self.assertEquals(self.GetPropList(node_name),
240                          ['compatible', 'reg', 'prop-int'])
241        node = self.fdt.path_offset('/%s' % node_name)
242        self.assertEquals(self.fdt.delprop(node, 'reg'), 0)
243        self.assertEquals(self.GetPropList(node_name),
244                          ['compatible', 'prop-int'])
245
246    def testHeader(self):
247        """Test that we can access the header values"""
248        self.assertEquals(self.fdt.totalsize(), len(self.fdt._fdt))
249        self.assertEquals(self.fdt.off_dt_struct(), 88)
250
251    def testPack(self):
252        """Test that we can pack the tree after deleting something"""
253        orig_size = self.fdt.totalsize()
254        node = self.fdt.path_offset('/subnode@2', QUIET_NOTFOUND)
255        self.assertEquals(self.fdt.delprop(node, 'prop-int'), 0)
256        self.assertEquals(orig_size, self.fdt.totalsize())
257        self.assertEquals(self.fdt.pack(), 0)
258        self.assertTrue(self.fdt.totalsize() < orig_size)
259
260    def testBadPropertyOffset(self):
261        """Test that bad property offsets are detected"""
262        with self.assertRaises(FdtException) as e:
263            self.fdt.get_property_by_offset(13)
264        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
265        with self.assertRaises(FdtException) as e:
266            self.fdt.first_property_offset(3)
267        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
268        with self.assertRaises(FdtException) as e:
269            self.fdt.next_property_offset(3)
270        self.assertEquals(e.exception.err, -libfdt.BADOFFSET)
271
272    def testBadPathOffset(self):
273        """Test that bad path names are detected"""
274        with self.assertRaisesRegexp(FdtException, get_err(libfdt.BADPATH)):
275            self.fdt.path_offset('not-present')
276
277    def testQuietAll(self):
278        """Check that exceptions can be masked by QUIET_ALL"""
279        self.assertEquals(-libfdt.NOTFOUND,
280                          self.fdt.path_offset('/missing', QUIET_ALL))
281        self.assertEquals(-libfdt.BADOFFSET,
282                          self.fdt.get_property_by_offset(13, QUIET_ALL))
283        self.assertEquals(-libfdt.BADPATH,
284                          self.fdt.path_offset('missing', QUIET_ALL))
285
286
287if __name__ == "__main__":
288    unittest.main()
289