u-boot/tools/binman/image.py

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# Copyright (c) 2016 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
# SPDX-License-Identifier: GPL-2.0+
#
# Class for an image, the output of binman
#
from collections import OrderedDict
from operator import attrgetter
import entry
from entry import Entry
import fdt_util
import tools
class Image:
"""A Image, representing an output from binman
An image is comprised of a collection of entries each containing binary
data. The image size must be large enough to hold all of this data.
This class implements the various operations needed for images.
Atrtributes:
_node: Node object that contains the image definition in device tree
_name: Image name
_size: Image size in bytes, or None if not known yet
_align_size: Image size alignment, or None
_pad_before: Number of bytes before the first entry starts. This
effectively changes the place where entry position 0 starts
_pad_after: Number of bytes after the last entry ends. The last
entry will finish on or before this boundary
_pad_byte: Byte to use to pad the image where there is no entry
_filename: Output filename for image
_sort: True if entries should be sorted by position, False if they
must be in-order in the device tree description
_skip_at_start: Number of bytes before the first entry starts. These
effecively adjust the starting position of entries. For example,
if _pad_before is 16, then the first entry would start at 16.
An entry with pos = 20 would in fact be written at position 4
in the image file.
_end_4gb: Indicates that the image ends at the 4GB boundary. This is
used for x86 images, which want to use positions such that a
memory address (like 0xff800000) is the first entry position.
This causes _skip_at_start to be set to the starting memory
address.
_entries: OrderedDict() of entries
"""
def __init__(self, name, node):
self._node = node
self._name = name
self._size = None
self._align_size = None
self._pad_before = 0
self._pad_after = 0
self._pad_byte = 0
self._filename = '%s.bin' % self._name
self._sort = False
self._skip_at_start = 0
self._end_4gb = False
self._entries = OrderedDict()
self._ReadNode()
self._ReadEntries()
def _ReadNode(self):
"""Read properties from the image node"""
self._size = fdt_util.GetInt(self._node, 'size')
self._align_size = fdt_util.GetInt(self._node, 'align-size')
if tools.NotPowerOfTwo(self._align_size):
self._Raise("Alignment size %s must be a power of two" %
self._align_size)
self._pad_before = fdt_util.GetInt(self._node, 'pad-before', 0)
self._pad_after = fdt_util.GetInt(self._node, 'pad-after', 0)
self._pad_byte = fdt_util.GetInt(self._node, 'pad-byte', 0)
filename = fdt_util.GetString(self._node, 'filename')
if filename:
self._filename = filename
self._sort = fdt_util.GetBool(self._node, 'sort-by-pos')
self._end_4gb = fdt_util.GetBool(self._node, 'end-at-4gb')
if self._end_4gb and not self._size:
self._Raise("Image size must be provided when using end-at-4gb")
if self._end_4gb:
self._skip_at_start = 0x100000000 - self._size
def CheckSize(self):
"""Check that the image contents does not exceed its size, etc."""
contents_size = 0
for entry in self._entries.values():
contents_size = max(contents_size, entry.pos + entry.size)
contents_size -= self._skip_at_start
size = self._size
if not size:
size = self._pad_before + contents_size + self._pad_after
size = tools.Align(size, self._align_size)
if self._size and contents_size > self._size:
self._Raise("contents size %#x (%d) exceeds image size %#x (%d)" %
(contents_size, contents_size, self._size, self._size))
if not self._size:
self._size = size
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))
def _Raise(self, msg):
"""Raises an error for this image
Args:
msg: Error message to use in the raise string
Raises:
ValueError()
"""
raise ValueError("Image '%s': %s" % (self._node.path, msg))
def _ReadEntries(self):
for node in self._node.subnodes:
self._entries[node.name] = Entry.Create(self, node)
def FindEntryType(self, etype):
"""Find an entry type in the image
Args:
etype: Entry type to find
Returns:
entry matching that type, or None if not found
"""
for entry in self._entries.values():
if entry.etype == etype:
return entry
return None
def GetEntryContents(self):
"""Call ObtainContents() for each entry
This calls each entry's ObtainContents() a few times until they all
return True. We stop calling an entry's function once it returns
True. This allows the contents of one entry to depend on another.
After 3 rounds we give up since it's likely an error.
"""
todo = self._entries.values()
for passnum in range(3):
next_todo = []
for entry in todo:
if not entry.ObtainContents():
next_todo.append(entry)
todo = next_todo
if not todo:
break
def _SetEntryPosSize(self, name, pos, size):
"""Set the position and size of an entry
Args:
name: Entry name to update
pos: New position
size: New size
"""
entry = self._entries.get(name)
if not entry:
self._Raise("Unable to set pos/size for unknown entry '%s'" % name)
entry.SetPositionSize(self._skip_at_start + pos, size)
def GetEntryPositions(self):
"""Handle entries that want to set the position/size of other entries
This calls each entry's GetPositions() method. If it returns a list
of entries to update, it updates them.
"""
for entry in self._entries.values():
pos_dict = entry.GetPositions()
for name, info in pos_dict.iteritems():
self._SetEntryPosSize(name, *info)
def PackEntries(self):
"""Pack all entries into the image"""
pos = self._skip_at_start
for entry in self._entries.values():
pos = entry.Pack(pos)
def _SortEntries(self):
"""Sort entries by position"""
entries = sorted(self._entries.values(), key=lambda entry: entry.pos)
self._entries.clear()
for entry in entries:
self._entries[entry._node.name] = entry
def CheckEntries(self):
"""Check that entries do not overlap or extend outside the image"""
if self._sort:
self._SortEntries()
pos = 0
prev_name = 'None'
for entry in self._entries.values():
if (entry.pos < self._skip_at_start or
entry.pos >= self._skip_at_start + self._size):
entry.Raise("Position %#x (%d) is outside the image starting "
"at %#x (%d)" %
(entry.pos, entry.pos, self._skip_at_start,
self._skip_at_start))
if entry.pos < pos:
entry.Raise("Position %#x (%d) overlaps with previous entry '%s' "
"ending at %#x (%d)" %
(entry.pos, entry.pos, prev_name, pos, pos))
pos = entry.pos + entry.size
prev_name = entry.GetPath()
def ProcessEntryContents(self):
"""Call the ProcessContents() method for each entry
This is intended to adjust the contents as needed by the entry type.
"""
for entry in self._entries.values():
entry.ProcessContents()
def BuildImage(self):
"""Write the image to a file"""
fname = tools.GetOutputFilename(self._filename)
with open(fname, 'wb') as fd:
fd.write(chr(self._pad_byte) * self._size)
for entry in self._entries.values():
data = entry.GetData()
fd.seek(self._pad_before + entry.pos - self._skip_at_start)
fd.write(data)