xref: /openbmc/u-boot/tools/dtoc/fdt_util.py (revision f48f2b729bf891aa6c1f752d5f8e06e44dd8b0b4) 
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 tempfile
12
13import command
14import tools
15
16def fdt32_to_cpu(val):
17    """Convert a device tree cell to an integer
18
19    Args:
20        Value to convert (4-character string representing the cell value)
21
22    Return:
23        A native-endian integer value
24    """
25    return struct.unpack('>I', val)[0]
26
27def EnsureCompiled(fname):
28    """Compile an fdt .dts source file into a .dtb binary blob if needed.
29
30    Args:
31        fname: Filename (if .dts it will be compiled). It not it will be
32            left alone
33
34    Returns:
35        Filename of resulting .dtb file
36    """
37    _, ext = os.path.splitext(fname)
38    if ext != '.dts':
39        return fname
40
41    dts_input = tools.GetOutputFilename('source.dts')
42    dtb_output = tools.GetOutputFilename('source.dtb')
43
44    search_paths = [os.path.join(os.getcwd(), 'include')]
45    root, _ = os.path.splitext(fname)
46    args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
47    args += ['-Ulinux']
48    for path in search_paths:
49        args.extend(['-I', path])
50    args += ['-o', dts_input, fname]
51    command.Run('cc', *args)
52
53    # If we don't have a directory, put it in the tools tempdir
54    search_list = []
55    for path in search_paths:
56        search_list.extend(['-i', path])
57    args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb']
58    args.extend(search_list)
59    args.append(dts_input)
60    command.Run('dtc', *args)
61    return dtb_output
62
63def GetInt(node, propname, default=None):
64    prop = node.props.get(propname)
65    if not prop:
66        return default
67    value = fdt32_to_cpu(prop.value)
68    if type(value) == type(list):
69        raise ValueError("Node '%s' property '%' has list value: expecting"
70                         "a single integer" % (node.name, propname))
71    return value
72
73def GetString(node, propname, default=None):
74    prop = node.props.get(propname)
75    if not prop:
76        return default
77    value = prop.value
78    if type(value) == type(list):
79        raise ValueError("Node '%s' property '%' has list value: expecting"
80                         "a single string" % (node.name, propname))
81    return value
82
83def GetBool(node, propname, default=False):
84    if propname in node.props:
85        return True
86    return default
87