xref: /openbmc/u-boot/tools/dtoc/fdt_util.py (revision e9c847c3) 
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        val = val.encode('raw_unicode_escape')
28    return struct.unpack('>I', val)[0]
29
30def EnsureCompiled(fname):
31    """Compile an fdt .dts source file into a .dtb binary blob if needed.
32
33    Args:
34        fname: Filename (if .dts it will be compiled). It not it will be
35            left alone
36
37    Returns:
38        Filename of resulting .dtb file
39    """
40    _, ext = os.path.splitext(fname)
41    if ext != '.dts':
42        return fname
43
44    dts_input = tools.GetOutputFilename('source.dts')
45    dtb_output = tools.GetOutputFilename('source.dtb')
46
47    search_paths = [os.path.join(os.getcwd(), 'include')]
48    root, _ = os.path.splitext(fname)
49    args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
50    args += ['-Ulinux']
51    for path in search_paths:
52        args.extend(['-I', path])
53    args += ['-o', dts_input, fname]
54    command.Run('cc', *args)
55
56    # If we don't have a directory, put it in the tools tempdir
57    search_list = []
58    for path in search_paths:
59        search_list.extend(['-i', path])
60    args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb']
61    args.extend(search_list)
62    args.append(dts_input)
63    command.Run('dtc', *args)
64    return dtb_output
65
66def GetInt(node, propname, default=None):
67    prop = node.props.get(propname)
68    if not prop:
69        return default
70    value = fdt32_to_cpu(prop.value)
71    if type(value) == type(list):
72        raise ValueError("Node '%s' property '%' has list value: expecting"
73                         "a single integer" % (node.name, propname))
74    return value
75
76def GetString(node, propname, default=None):
77    prop = node.props.get(propname)
78    if not prop:
79        return default
80    value = prop.value
81    if type(value) == type(list):
82        raise ValueError("Node '%s' property '%' has list value: expecting"
83                         "a single string" % (node.name, propname))
84    return value
85
86def GetBool(node, propname, default=False):
87    if propname in node.props:
88        return True
89    return default
90