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1 | # Copyright (c) 2016 Google, Inc |
2 | # | |
3 | # SPDX-License-Identifier: GPL-2.0+ | |
4 | # | |
5 | # Base class for all entries | |
6 | # | |
7 | ||
8 | # importlib was introduced in Python 2.7 but there was a report of it not | |
9 | # working in 2.7.12, so we work around this: | |
10 | # http://lists.denx.de/pipermail/u-boot/2016-October/269729.html | |
11 | try: | |
12 | import importlib | |
13 | have_importlib = True | |
14 | except: | |
15 | have_importlib = False | |
16 | ||
17 | import fdt_util | |
18 | import tools | |
19 | ||
20 | modules = {} | |
21 | ||
22 | class Entry(object): | |
23 | """An Entry in the image | |
24 | ||
25 | An entry corresponds to a single node in the device-tree description | |
26 | of the image. Each entry ends up being a part of the final image. | |
27 | Entries can be placed either right next to each other, or with padding | |
28 | between them. The type of the entry determines the data that is in it. | |
29 | ||
30 | This class is not used by itself. All entry objects are subclasses of | |
31 | Entry. | |
32 | ||
33 | Attributes: | |
34 | image: The image containing this entry | |
35 | node: The node that created this entry | |
36 | pos: Absolute position of entry within the image, None if not known | |
37 | size: Entry size in bytes, None if not known | |
38 | contents_size: Size of contents in bytes, 0 by default | |
39 | align: Entry start position alignment, or None | |
40 | align_size: Entry size alignment, or None | |
41 | align_end: Entry end position alignment, or None | |
42 | pad_before: Number of pad bytes before the contents, 0 if none | |
43 | pad_after: Number of pad bytes after the contents, 0 if none | |
44 | data: Contents of entry (string of bytes) | |
45 | """ | |
46 | def __init__(self, image, etype, node, read_node=True): | |
47 | self.image = image | |
48 | self.etype = etype | |
49 | self._node = node | |
50 | self.pos = None | |
51 | self.size = None | |
52 | self.contents_size = 0 | |
53 | self.align = None | |
54 | self.align_size = None | |
55 | self.align_end = None | |
56 | self.pad_before = 0 | |
57 | self.pad_after = 0 | |
58 | self.pos_unset = False | |
59 | if read_node: | |
60 | self.ReadNode() | |
61 | ||
62 | @staticmethod | |
63 | def Create(image, node, etype=None): | |
64 | """Create a new entry for a node. | |
65 | ||
66 | Args: | |
67 | image: Image object containing this node | |
68 | node: Node object containing information about the entry to create | |
69 | etype: Entry type to use, or None to work it out (used for tests) | |
70 | ||
71 | Returns: | |
72 | A new Entry object of the correct type (a subclass of Entry) | |
73 | """ | |
74 | if not etype: | |
75 | etype = fdt_util.GetString(node, 'type', node.name) | |
76 | module_name = etype.replace('-', '_') | |
77 | module = modules.get(module_name) | |
78 | ||
79 | # Import the module if we have not already done so. | |
80 | if not module: | |
81 | try: | |
82 | if have_importlib: | |
83 | module = importlib.import_module(module_name) | |
84 | else: | |
85 | module = __import__(module_name) | |
86 | except ImportError: | |
87 | raise ValueError("Unknown entry type '%s' in node '%s'" % | |
88 | (etype, node.path)) | |
89 | modules[module_name] = module | |
90 | ||
91 | # Call its constructor to get the object we want. | |
92 | obj = getattr(module, 'Entry_%s' % module_name) | |
93 | return obj(image, etype, node) | |
94 | ||
95 | def ReadNode(self): | |
96 | """Read entry information from the node | |
97 | ||
98 | This reads all the fields we recognise from the node, ready for use. | |
99 | """ | |
100 | self.pos = fdt_util.GetInt(self._node, 'pos') | |
101 | self.size = fdt_util.GetInt(self._node, 'size') | |
102 | self.align = fdt_util.GetInt(self._node, 'align') | |
103 | if tools.NotPowerOfTwo(self.align): | |
104 | raise ValueError("Node '%s': Alignment %s must be a power of two" % | |
105 | (self._node.path, self.align)) | |
106 | self.pad_before = fdt_util.GetInt(self._node, 'pad-before', 0) | |
107 | self.pad_after = fdt_util.GetInt(self._node, 'pad-after', 0) | |
108 | self.align_size = fdt_util.GetInt(self._node, 'align-size') | |
109 | if tools.NotPowerOfTwo(self.align_size): | |
110 | raise ValueError("Node '%s': Alignment size %s must be a power " | |
111 | "of two" % (self._node.path, self.align_size)) | |
112 | self.align_end = fdt_util.GetInt(self._node, 'align-end') | |
113 | self.pos_unset = fdt_util.GetBool(self._node, 'pos-unset') | |
114 | ||
115 | def ObtainContents(self): | |
116 | """Figure out the contents of an entry. | |
117 | ||
118 | Returns: | |
119 | True if the contents were found, False if another call is needed | |
120 | after the other entries are processed. | |
121 | """ | |
122 | # No contents by default: subclasses can implement this | |
123 | return True | |
124 | ||
125 | def Pack(self, pos): | |
126 | """Figure out how to pack the entry into the image | |
127 | ||
128 | Most of the time the entries are not fully specified. There may be | |
129 | an alignment but no size. In that case we take the size from the | |
130 | contents of the entry. | |
131 | ||
132 | If an entry has no hard-coded position, it will be placed at @pos. | |
133 | ||
134 | Once this function is complete, both the position and size of the | |
135 | entry will be know. | |
136 | ||
137 | Args: | |
138 | Current image position pointer | |
139 | ||
140 | Returns: | |
141 | New image position pointer (after this entry) | |
142 | """ | |
143 | if self.pos is None: | |
144 | if self.pos_unset: | |
145 | self.Raise('No position set with pos-unset: should another ' | |
146 | 'entry provide this correct position?') | |
147 | self.pos = tools.Align(pos, self.align) | |
148 | needed = self.pad_before + self.contents_size + self.pad_after | |
149 | needed = tools.Align(needed, self.align_size) | |
150 | size = self.size | |
151 | if not size: | |
152 | size = needed | |
153 | new_pos = self.pos + size | |
154 | aligned_pos = tools.Align(new_pos, self.align_end) | |
155 | if aligned_pos != new_pos: | |
156 | size = aligned_pos - self.pos | |
157 | new_pos = aligned_pos | |
158 | ||
159 | if not self.size: | |
160 | self.size = size | |
161 | ||
162 | if self.size < needed: | |
163 | self.Raise("Entry contents size is %#x (%d) but entry size is " | |
164 | "%#x (%d)" % (needed, needed, self.size, self.size)) | |
165 | # Check that the alignment is correct. It could be wrong if the | |
166 | # and pos or size values were provided (i.e. not calculated), but | |
167 | # conflict with the provided alignment values | |
168 | if self.size != tools.Align(self.size, self.align_size): | |
169 | self.Raise("Size %#x (%d) does not match align-size %#x (%d)" % | |
170 | (self.size, self.size, self.align_size, self.align_size)) | |
171 | if self.pos != tools.Align(self.pos, self.align): | |
172 | self.Raise("Position %#x (%d) does not match align %#x (%d)" % | |
173 | (self.pos, self.pos, self.align, self.align)) | |
174 | ||
175 | return new_pos | |
176 | ||
177 | def Raise(self, msg): | |
178 | """Convenience function to raise an error referencing a node""" | |
179 | raise ValueError("Node '%s': %s" % (self._node.path, msg)) | |
180 | ||
181 | def GetPath(self): | |
182 | """Get the path of a node | |
183 | ||
184 | Returns: | |
185 | Full path of the node for this entry | |
186 | """ | |
187 | return self._node.path | |
188 | ||
189 | def GetData(self): | |
190 | return self.data | |
191 | ||
192 | def GetPositions(self): | |
193 | return {} | |
194 | ||
195 | def SetPositionSize(self, pos, size): | |
196 | self.pos = pos | |
197 | self.size = size | |
198 | ||
199 | def ProcessContents(self): | |
200 | pass | |
19790632 SG |
201 | |
202 | def WriteSymbols(self, image): | |
203 | """Write symbol values into binary files for access at run time | |
204 | ||
205 | Args: | |
206 | image: Image containing the entry | |
207 | """ | |
208 | pass |