xref: /openbmc/u-boot/tools/dtoc/fdt_util.py (revision 85fc970d) 
1#!/usr/bin/python
2#
3# Copyright (C) 2016 Google, Inc
4# Written by Simon Glass <sjg@chromium.org>
5#
6# SPDX-License-Identifier:      GPL-2.0+
7#
8
9import os
10import struct
11import sys
12import tempfile
13
14import command
15import tools
16
17def fdt32_to_cpu(val):
18    """Convert a device tree cell to an integer
19
20    Args:
21        Value to convert (4-character string representing the cell value)
22
23    Return:
24        A native-endian integer value
25    """
26    if sys.version_info > (3, 0):
27        if isinstance(val, bytes):
28            val = val.decode('utf-8')
29        val = val.encode('raw_unicode_escape')
30    return struct.unpack('>I', val)[0]
31
32def EnsureCompiled(fname):
33    """Compile an fdt .dts source file into a .dtb binary blob if needed.
34
35    Args:
36        fname: Filename (if .dts it will be compiled). It not it will be
37            left alone
38
39    Returns:
40        Filename of resulting .dtb file
41    """
42    _, ext = os.path.splitext(fname)
43    if ext != '.dts':
44        return fname
45
46    dts_input = tools.GetOutputFilename('source.dts')
47    dtb_output = tools.GetOutputFilename('source.dtb')
48
49    search_paths = [os.path.join(os.getcwd(), 'include')]
50    root, _ = os.path.splitext(fname)
51    args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
52    args += ['-Ulinux']
53    for path in search_paths:
54        args.extend(['-I', path])
55    args += ['-o', dts_input, fname]
56    command.Run('cc', *args)
57
58    # If we don't have a directory, put it in the tools tempdir
59    search_list = []
60    for path in search_paths:
61        search_list.extend(['-i', path])
62    args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb']
63    args.extend(search_list)
64    args.append(dts_input)
65    command.Run('dtc', *args)
66    return dtb_output
67
68def GetInt(node, propname, default=None):
69    prop = node.props.get(propname)
70    if not prop:
71        return default
72    value = fdt32_to_cpu(prop.value)
73    if type(value) == type(list):
74        raise ValueError("Node '%s' property '%' has list value: expecting"
75                         "a single integer" % (node.name, propname))
76    return value
77
78def GetString(node, propname, default=None):
79    prop = node.props.get(propname)
80    if not prop:
81        return default
82    value = prop.value
83    if type(value) == type(list):
84        raise ValueError("Node '%s' property '%' has list value: expecting"
85                         "a single string" % (node.name, propname))
86    return value
87
88def GetBool(node, propname, default=False):
89    if propname in node.props:
90        return True
91    return default
92