| # SPDX-License-Identifier: GPL-2.0+ |
| # Copyright (c) 2016 Google, Inc |
| # |
| # 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 |
