xref: /openbmc/u-boot/tools/binman/entry.py (revision d6736689)
1# SPDX-License-Identifier: GPL-2.0+
2# Copyright (c) 2016 Google, Inc
3#
4# Base class for all entries
5#
6
7from __future__ import print_function
8
9# importlib was introduced in Python 2.7 but there was a report of it not
10# working in 2.7.12, so we work around this:
11# http://lists.denx.de/pipermail/u-boot/2016-October/269729.html
12try:
13    import importlib
14    have_importlib = True
15except:
16    have_importlib = False
17
18import fdt_util
19import os
20import sys
21import tools
22
23modules = {}
24
25our_path = os.path.dirname(os.path.realpath(__file__))
26
27class Entry(object):
28    """An Entry in the section
29
30    An entry corresponds to a single node in the device-tree description
31    of the section. Each entry ends up being a part of the final section.
32    Entries can be placed either right next to each other, or with padding
33    between them. The type of the entry determines the data that is in it.
34
35    This class is not used by itself. All entry objects are subclasses of
36    Entry.
37
38    Attributes:
39        section: The section containing this entry
40        node: The node that created this entry
41        pos: Absolute position of entry within the section, None if not known
42        size: Entry size in bytes, None if not known
43        contents_size: Size of contents in bytes, 0 by default
44        align: Entry start position alignment, or None
45        align_size: Entry size alignment, or None
46        align_end: Entry end position alignment, or None
47        pad_before: Number of pad bytes before the contents, 0 if none
48        pad_after: Number of pad bytes after the contents, 0 if none
49        data: Contents of entry (string of bytes)
50    """
51    def __init__(self, section, etype, node, read_node=True, name_prefix=''):
52        self.section = section
53        self.etype = etype
54        self._node = node
55        self.name = node and (name_prefix + node.name) or 'none'
56        self.pos = None
57        self.size = None
58        self.data = ''
59        self.contents_size = 0
60        self.align = None
61        self.align_size = None
62        self.align_end = None
63        self.pad_before = 0
64        self.pad_after = 0
65        self.pos_unset = False
66        if read_node:
67            self.ReadNode()
68
69    @staticmethod
70    def Create(section, node, etype=None):
71        """Create a new entry for a node.
72
73        Args:
74            section:  Image object containing this node
75            node:   Node object containing information about the entry to create
76            etype:  Entry type to use, or None to work it out (used for tests)
77
78        Returns:
79            A new Entry object of the correct type (a subclass of Entry)
80        """
81        if not etype:
82            etype = fdt_util.GetString(node, 'type', node.name)
83
84        # Convert something like 'u-boot@0' to 'u_boot' since we are only
85        # interested in the type.
86        module_name = etype.replace('-', '_')
87        if '@' in module_name:
88            module_name = module_name.split('@')[0]
89        module = modules.get(module_name)
90
91        # Also allow entry-type modules to be brought in from the etype directory.
92
93        # Import the module if we have not already done so.
94        if not module:
95            old_path = sys.path
96            sys.path.insert(0, os.path.join(our_path, 'etype'))
97            try:
98                if have_importlib:
99                    module = importlib.import_module(module_name)
100                else:
101                    module = __import__(module_name)
102            except ImportError:
103                raise ValueError("Unknown entry type '%s' in node '%s'" %
104                        (etype, node.path))
105            finally:
106                sys.path = old_path
107            modules[module_name] = module
108
109        # Call its constructor to get the object we want.
110        obj = getattr(module, 'Entry_%s' % module_name)
111        return obj(section, etype, node)
112
113    def ReadNode(self):
114        """Read entry information from the node
115
116        This reads all the fields we recognise from the node, ready for use.
117        """
118        self.pos = fdt_util.GetInt(self._node, 'pos')
119        self.size = fdt_util.GetInt(self._node, 'size')
120        self.align = fdt_util.GetInt(self._node, 'align')
121        if tools.NotPowerOfTwo(self.align):
122            raise ValueError("Node '%s': Alignment %s must be a power of two" %
123                             (self._node.path, self.align))
124        self.pad_before = fdt_util.GetInt(self._node, 'pad-before', 0)
125        self.pad_after = fdt_util.GetInt(self._node, 'pad-after', 0)
126        self.align_size = fdt_util.GetInt(self._node, 'align-size')
127        if tools.NotPowerOfTwo(self.align_size):
128            raise ValueError("Node '%s': Alignment size %s must be a power "
129                             "of two" % (self._node.path, self.align_size))
130        self.align_end = fdt_util.GetInt(self._node, 'align-end')
131        self.pos_unset = fdt_util.GetBool(self._node, 'pos-unset')
132
133    def AddMissingProperties(self):
134        """Add new properties to the device tree as needed for this entry"""
135        for prop in ['pos', 'size']:
136            if not prop in self._node.props:
137                self._node.AddZeroProp(prop)
138
139    def SetCalculatedProperties(self):
140        """Set the value of device-tree properties calculated by binman"""
141        self._node.SetInt('pos', self.pos)
142        self._node.SetInt('size', self.size)
143
144    def ProcessFdt(self, fdt):
145        return True
146
147    def SetPrefix(self, prefix):
148        """Set the name prefix for a node
149
150        Args:
151            prefix: Prefix to set, or '' to not use a prefix
152        """
153        if prefix:
154            self.name = prefix + self.name
155
156    def SetContents(self, data):
157        """Set the contents of an entry
158
159        This sets both the data and content_size properties
160
161        Args:
162            data: Data to set to the contents (string)
163        """
164        self.data = data
165        self.contents_size = len(self.data)
166
167    def ProcessContentsUpdate(self, data):
168        """Update the contens of an entry, after the size is fixed
169
170        This checks that the new data is the same size as the old.
171
172        Args:
173            data: Data to set to the contents (string)
174
175        Raises:
176            ValueError if the new data size is not the same as the old
177        """
178        if len(data) != self.contents_size:
179            self.Raise('Cannot update entry size from %d to %d' %
180                       (len(data), self.contents_size))
181        self.SetContents(data)
182
183    def ObtainContents(self):
184        """Figure out the contents of an entry.
185
186        Returns:
187            True if the contents were found, False if another call is needed
188            after the other entries are processed.
189        """
190        # No contents by default: subclasses can implement this
191        return True
192
193    def Pack(self, pos):
194        """Figure out how to pack the entry into the section
195
196        Most of the time the entries are not fully specified. There may be
197        an alignment but no size. In that case we take the size from the
198        contents of the entry.
199
200        If an entry has no hard-coded position, it will be placed at @pos.
201
202        Once this function is complete, both the position and size of the
203        entry will be know.
204
205        Args:
206            Current section position pointer
207
208        Returns:
209            New section position pointer (after this entry)
210        """
211        if self.pos is None:
212            if self.pos_unset:
213                self.Raise('No position set with pos-unset: should another '
214                           'entry provide this correct position?')
215            self.pos = tools.Align(pos, self.align)
216        needed = self.pad_before + self.contents_size + self.pad_after
217        needed = tools.Align(needed, self.align_size)
218        size = self.size
219        if not size:
220            size = needed
221        new_pos = self.pos + size
222        aligned_pos = tools.Align(new_pos, self.align_end)
223        if aligned_pos != new_pos:
224            size = aligned_pos - self.pos
225            new_pos = aligned_pos
226
227        if not self.size:
228            self.size = size
229
230        if self.size < needed:
231            self.Raise("Entry contents size is %#x (%d) but entry size is "
232                       "%#x (%d)" % (needed, needed, self.size, self.size))
233        # Check that the alignment is correct. It could be wrong if the
234        # and pos or size values were provided (i.e. not calculated), but
235        # conflict with the provided alignment values
236        if self.size != tools.Align(self.size, self.align_size):
237            self.Raise("Size %#x (%d) does not match align-size %#x (%d)" %
238                  (self.size, self.size, self.align_size, self.align_size))
239        if self.pos != tools.Align(self.pos, self.align):
240            self.Raise("Position %#x (%d) does not match align %#x (%d)" %
241                  (self.pos, self.pos, self.align, self.align))
242
243        return new_pos
244
245    def Raise(self, msg):
246        """Convenience function to raise an error referencing a node"""
247        raise ValueError("Node '%s': %s" % (self._node.path, msg))
248
249    def GetPath(self):
250        """Get the path of a node
251
252        Returns:
253            Full path of the node for this entry
254        """
255        return self._node.path
256
257    def GetData(self):
258        return self.data
259
260    def GetPositions(self):
261        return {}
262
263    def SetPositionSize(self, pos, size):
264        self.pos = pos
265        self.size = size
266
267    def ProcessContents(self):
268        pass
269
270    def WriteSymbols(self, section):
271        """Write symbol values into binary files for access at run time
272
273        Args:
274          section: Section containing the entry
275        """
276        pass
277
278    def CheckPosition(self):
279        """Check that the entry positions are correct
280
281        This is used for entries which have extra position requirements (other
282        than having to be fully inside their section). Sub-classes can implement
283        this function and raise if there is a problem.
284        """
285        pass
286
287    def WriteMap(self, fd, indent):
288        """Write a map of the entry to a .map file
289
290        Args:
291            fd: File to write the map to
292            indent: Curent indent level of map (0=none, 1=one level, etc.)
293        """
294        print('%s%08x  %08x  %s' % (' ' * indent, self.pos, self.size,
295                                    self.name), file=fd)
296