| # Copyright (c) 2016 Google, Inc | |
| # | |
| # SPDX-License-Identifier: GPL-2.0+ | |
| # | |
| # Base class for all entries | |
| # | |
| # importlib was introduced in Python 2.7 but there was a report of it not | |
| # working in 2.7.12, so we work around this: | |
| # http://lists.denx.de/pipermail/u-boot/2016-October/269729.html | |
| try: | |
| import importlib | |
| have_importlib = True | |
| except: | |
| have_importlib = False | |
| import fdt_util | |
| import tools | |
| modules = {} | |
| class Entry(object): | |
| """An Entry in the image | |
| An entry corresponds to a single node in the device-tree description | |
| of the image. Each entry ends up being a part of the final image. | |
| Entries can be placed either right next to each other, or with padding | |
| between them. The type of the entry determines the data that is in it. | |
| This class is not used by itself. All entry objects are subclasses of | |
| Entry. | |
| Attributes: | |
| image: The image containing this entry | |
| node: The node that created this entry | |
| pos: Absolute position of entry within the image, None if not known | |
| size: Entry size in bytes, None if not known | |
| contents_size: Size of contents in bytes, 0 by default | |
| align: Entry start position alignment, or None | |
| align_size: Entry size alignment, or None | |
| align_end: Entry end position alignment, or None | |
| pad_before: Number of pad bytes before the contents, 0 if none | |
| pad_after: Number of pad bytes after the contents, 0 if none | |
| data: Contents of entry (string of bytes) | |
| """ | |
| def __init__(self, image, etype, node, read_node=True): | |
| self.image = image | |
| self.etype = etype | |
| self._node = node | |
| self.pos = None | |
| self.size = None | |
| self.contents_size = 0 | |
| self.align = None | |
| self.align_size = None | |
| self.align_end = None | |
| self.pad_before = 0 | |
| self.pad_after = 0 | |
| self.pos_unset = False | |
| if read_node: | |
| self.ReadNode() | |
| @staticmethod | |
| def Create(image, node, etype=None): | |
| """Create a new entry for a node. | |
| Args: | |
| image: Image object containing this node | |
| node: Node object containing information about the entry to create | |
| etype: Entry type to use, or None to work it out (used for tests) | |
| Returns: | |
| A new Entry object of the correct type (a subclass of Entry) | |
| """ | |
| if not etype: | |
| etype = fdt_util.GetString(node, 'type', node.name) | |
| module_name = etype.replace('-', '_') | |
| module = modules.get(module_name) | |
| # Import the module if we have not already done so. | |
| if not module: | |
| try: | |
| if have_importlib: | |
| module = importlib.import_module(module_name) | |
| else: | |
| module = __import__(module_name) | |
| except ImportError: | |
| raise ValueError("Unknown entry type '%s' in node '%s'" % | |
| (etype, node.path)) | |
| modules[module_name] = module | |
| # Call its constructor to get the object we want. | |
| obj = getattr(module, 'Entry_%s' % module_name) | |
| return obj(image, etype, node) | |
| def ReadNode(self): | |
| """Read entry information from the node | |
| This reads all the fields we recognise from the node, ready for use. | |
| """ | |
| self.pos = fdt_util.GetInt(self._node, 'pos') | |
| self.size = fdt_util.GetInt(self._node, 'size') | |
| self.align = fdt_util.GetInt(self._node, 'align') | |
| if tools.NotPowerOfTwo(self.align): | |
| raise ValueError("Node '%s': Alignment %s must be a power of two" % | |
| (self._node.path, self.align)) | |
| self.pad_before = fdt_util.GetInt(self._node, 'pad-before', 0) | |
| self.pad_after = fdt_util.GetInt(self._node, 'pad-after', 0) | |
| self.align_size = fdt_util.GetInt(self._node, 'align-size') | |
| if tools.NotPowerOfTwo(self.align_size): | |
| raise ValueError("Node '%s': Alignment size %s must be a power " | |
| "of two" % (self._node.path, self.align_size)) | |
| self.align_end = fdt_util.GetInt(self._node, 'align-end') | |
| self.pos_unset = fdt_util.GetBool(self._node, 'pos-unset') | |
| def ObtainContents(self): | |
| """Figure out the contents of an entry. | |
| Returns: | |
| True if the contents were found, False if another call is needed | |
| after the other entries are processed. | |
| """ | |
| # No contents by default: subclasses can implement this | |
| return True | |
| def Pack(self, pos): | |
| """Figure out how to pack the entry into the image | |
| Most of the time the entries are not fully specified. There may be | |
| an alignment but no size. In that case we take the size from the | |
| contents of the entry. | |
| If an entry has no hard-coded position, it will be placed at @pos. | |
| Once this function is complete, both the position and size of the | |
| entry will be know. | |
| Args: | |
| Current image position pointer | |
| Returns: | |
| New image position pointer (after this entry) | |
| """ | |
| if self.pos is None: | |
| if self.pos_unset: | |
| self.Raise('No position set with pos-unset: should another ' | |
| 'entry provide this correct position?') | |
| self.pos = tools.Align(pos, self.align) | |
| needed = self.pad_before + self.contents_size + self.pad_after | |
| needed = tools.Align(needed, self.align_size) | |
| size = self.size | |
| if not size: | |
| size = needed | |
| new_pos = self.pos + size | |
| aligned_pos = tools.Align(new_pos, self.align_end) | |
| if aligned_pos != new_pos: | |
| size = aligned_pos - self.pos | |
| new_pos = aligned_pos | |
| if not self.size: | |
| self.size = size | |
| if self.size < needed: | |
| self.Raise("Entry contents size is %#x (%d) but entry size is " | |
| "%#x (%d)" % (needed, needed, self.size, self.size)) | |
| # Check that the alignment is correct. It could be wrong if the | |
| # and pos or size values were provided (i.e. not calculated), but | |
| # conflict with the provided alignment values | |
| if self.size != tools.Align(self.size, self.align_size): | |
| self.Raise("Size %#x (%d) does not match align-size %#x (%d)" % | |
| (self.size, self.size, self.align_size, self.align_size)) | |
| if self.pos != tools.Align(self.pos, self.align): | |
| self.Raise("Position %#x (%d) does not match align %#x (%d)" % | |
| (self.pos, self.pos, self.align, self.align)) | |
| return new_pos | |
| def Raise(self, msg): | |
| """Convenience function to raise an error referencing a node""" | |
| raise ValueError("Node '%s': %s" % (self._node.path, msg)) | |
| def GetPath(self): | |
| """Get the path of a node | |
| Returns: | |
| Full path of the node for this entry | |
| """ | |
| return self._node.path | |
| def GetData(self): | |
| return self.data | |
| def GetPositions(self): | |
| return {} | |
| def SetPositionSize(self, pos, size): | |
| self.pos = pos | |
| self.size = size | |
| def ProcessContents(self): | |
| pass | |
| def WriteSymbols(self, image): | |
| """Write symbol values into binary files for access at run time | |
| Args: | |
| image: Image containing the entry | |
| """ | |
| pass |