tools/binman/image.py

# SPDX-License-Identifier: GPL-2.0+
# Copyright (c) 2016 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
# Class for an image, the output of binman
#

from __future__ import print_function

from collections import OrderedDict
from operator import attrgetter
import re
import sys

from etype import fdtmap
from etype import image_header
import fdt
import fdt_util
import bsection
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
        _filename: Output filename for image
        _sections: Sections present in this image (may be one or more)

    Args:
        test: True if this is being called from a test of Images. This this case
            there is no device tree defining the structure of the section, so
            we create a section manually.
    """
    def __init__(self, name, node, test=False):
        self._node = node
        self._name = name
        self._size = None
        self._filename = '%s.bin' % self._name
        if test:
            self._section = bsection.Section('main-section', None, self._node,
                                             self, True)
        else:
            self._ReadNode()

    @classmethod
    def FromFile(cls, fname):
        """Convert an image file into an Image for use in binman

        Args:
            fname: Filename of image file to read

        Returns:
            Image object on success

        Raises:
            ValueError if something goes wrong
        """
        data = tools.ReadFile(fname)
        size = len(data)

        # First look for an image header
        pos = image_header.LocateHeaderOffset(data)
        if pos is None:
            # Look for the FDT map
            pos = fdtmap.LocateFdtmap(data)
        if pos is None:
            raise ValueError('Cannot find FDT map in image')

        # We don't know the FDT size, so check its header first
        probe_dtb = fdt.Fdt.FromData(
            data[pos + fdtmap.FDTMAP_HDR_LEN:pos + 256])
        dtb_size = probe_dtb.GetFdtObj().totalsize()
        fdtmap_data = data[pos:pos + dtb_size + fdtmap.FDTMAP_HDR_LEN]
        dtb = fdt.Fdt.FromData(fdtmap_data[fdtmap.FDTMAP_HDR_LEN:])
        dtb.Scan()

        # Return an Image with the associated nodes
        return Image('image', dtb.GetRoot())

    def _ReadNode(self):
        """Read properties from the image node"""
        self._size = fdt_util.GetInt(self._node, 'size')
        filename = fdt_util.GetString(self._node, 'filename')
        if filename:
            self._filename = filename
        self._section = bsection.Section('main-section', None, self._node, self)

    def Raise(self, msg):
        """Convenience function to raise an error referencing an image"""
        raise ValueError("Image '%s': %s" % (self._node.path, msg))

    def GetFdtSet(self):
        """Get the set of device tree files used by this image"""
        return self._section.GetFdtSet()

    def ExpandEntries(self):
        """Expand out any entries which have calculated sub-entries

        Some entries are expanded out at runtime, e.g. 'files', which produces
        a section containing a list of files. Process these entries so that
        this information is added to the device tree.
        """
        self._section.ExpandEntries()

    def AddMissingProperties(self):
        """Add properties that are not present in the device tree

        When binman has completed packing the entries the offset and size of
        each entry are known. But before this the device tree may not specify
        these. Add any missing properties, with a dummy value, so that the
        size of the entry is correct. That way we can insert the correct values
        later.
        """
        self._section.AddMissingProperties()

    def ProcessFdt(self, fdt):
        """Allow entries to adjust the device tree

        Some entries need to adjust the device tree for their purposes. This
        may involve adding or deleting properties.
        """
        return self._section.ProcessFdt(fdt)

    def GetEntryContents(self):
        """Call ObtainContents() for the section
        """
        self._section.GetEntryContents()

    def GetEntryOffsets(self):
        """Handle entries that want to set the offset/size of other entries

        This calls each entry's GetOffsets() method. If it returns a list
        of entries to update, it updates them.
        """
        self._section.GetEntryOffsets()

    def ResetForPack(self):
        """Reset offset/size fields so that packing can be done again"""
        self._section.ResetForPack()

    def PackEntries(self):
        """Pack all entries into the image"""
        self._section.PackEntries()

    def CheckSize(self):
        """Check that the image contents does not exceed its size, etc."""
        self._size = self._section.CheckSize()

    def CheckEntries(self):
        """Check that entries do not overlap or extend outside the image"""
        self._section.CheckEntries()

    def SetCalculatedProperties(self):
        self._section.SetCalculatedProperties()

    def SetImagePos(self):
        self._section.SetImagePos(0)

    def ProcessEntryContents(self):
        """Call the ProcessContents() method for each entry

        This is intended to adjust the contents as needed by the entry type.

        Returns:
            True if the new data size is OK, False if expansion is needed
        """
        return self._section.ProcessEntryContents()

    def WriteSymbols(self):
        """Write symbol values into binary files for access at run time"""
        self._section.WriteSymbols()

    def BuildImage(self):
        """Write the image to a file"""
        fname = tools.GetOutputFilename(self._filename)
        with open(fname, 'wb') as fd:
            self._section.BuildSection(fd, 0)

    def GetEntries(self):
        return self._section.GetEntries()

    def WriteMap(self):
        """Write a map of the image to a .map file

        Returns:
            Filename of map file written
        """
        filename = '%s.map' % self._name
        fname = tools.GetOutputFilename(filename)
        with open(fname, 'w') as fd:
            print('%8s  %8s  %8s  %s' % ('ImagePos', 'Offset', 'Size', 'Name'),
                  file=fd)
            self._section.WriteMap(fd, 0)
        return fname

    def BuildEntryList(self):
        """List the files in an image

        Returns:
            List of entry.EntryInfo objects describing all entries in the image
        """
        entries = []
        self._section.ListEntries(entries, 0)
        return entries