1# SPDX-License-Identifier: GPL-2.0+
2# Copyright (c) 2016 Google, Inc
3# Written by Simon Glass <sjg@chromium.org>
4#
5# Entry-type module for blobs, which are binary objects read from files
6#
7
8from binman.entry import Entry
9from dtoc import fdt_util
10from patman import tools
11from patman import tout
12
13class Entry_blob(Entry):
14    """Entry containing an arbitrary binary blob
15
16    Note: This should not be used by itself. It is normally used as a parent
17    class by other entry types.
18
19    Properties / Entry arguments:
20        - filename: Filename of file to read into entry
21        - compress: Compression algorithm to use:
22            none: No compression
23            lz4: Use lz4 compression (via 'lz4' command-line utility)
24
25    This entry reads data from a file and places it in the entry. The
26    default filename is often specified specified by the subclass. See for
27    example the 'u_boot' entry which provides the filename 'u-boot.bin'.
28
29    If compression is enabled, an extra 'uncomp-size' property is written to
30    the node (if enabled with -u) which provides the uncompressed size of the
31    data.
32    """
33    def __init__(self, section, etype, node):
34        super().__init__(section, etype, node)
35        self._filename = fdt_util.GetString(self._node, 'filename', self.etype)
36
37    def ObtainContents(self):
38        self._filename = self.GetDefaultFilename()
39        self._pathname = tools.GetInputFilename(self._filename,
40            self.external and self.section.GetAllowMissing())
41        # Allow the file to be missing
42        if not self._pathname:
43            self.SetContents(b'')
44            self.missing = True
45            return True
46
47        self.ReadBlobContents()
48        return True
49
50    def ReadBlobContents(self):
51        """Read blob contents into memory
52
53        This function compresses the data before storing if needed.
54
55        We assume the data is small enough to fit into memory. If this
56        is used for large filesystem image that might not be true.
57        In that case, Image.BuildImage() could be adjusted to use a
58        new Entry method which can read in chunks. Then we could copy
59        the data in chunks and avoid reading it all at once. For now
60        this seems like an unnecessary complication.
61        """
62        indata = tools.ReadFile(self._pathname)
63        data = self.CompressData(indata)
64        self.SetContents(data)
65        return True
66
67    def GetDefaultFilename(self):
68        return self._filename
69
70    def ProcessContents(self):
71        # The blob may have changed due to WriteSymbols()
72        return self.ProcessContentsUpdate(self.data)
73