xref: /openbmc/u-boot/tools/dtoc/fdt_util.py (revision cc8fb2f7) 
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 fdt_cells_to_cpu(val, cells):
33    """Convert one or two cells to a long integer
34
35    Args:
36        Value to convert (array of one or more 4-character strings)
37
38    Return:
39        A native-endian long value
40    """
41    if not cells:
42        return 0
43    out = long(fdt32_to_cpu(val[0]))
44    if cells == 2:
45        out = out << 32 | fdt32_to_cpu(val[1])
46    return out
47
48def EnsureCompiled(fname):
49    """Compile an fdt .dts source file into a .dtb binary blob if needed.
50
51    Args:
52        fname: Filename (if .dts it will be compiled). It not it will be
53            left alone
54
55    Returns:
56        Filename of resulting .dtb file
57    """
58    _, ext = os.path.splitext(fname)
59    if ext != '.dts':
60        return fname
61
62    dts_input = tools.GetOutputFilename('source.dts')
63    dtb_output = tools.GetOutputFilename('source.dtb')
64
65    search_paths = [os.path.join(os.getcwd(), 'include')]
66    root, _ = os.path.splitext(fname)
67    args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
68    args += ['-Ulinux']
69    for path in search_paths:
70        args.extend(['-I', path])
71    args += ['-o', dts_input, fname]
72    command.Run('cc', *args)
73
74    # If we don't have a directory, put it in the tools tempdir
75    search_list = []
76    for path in search_paths:
77        search_list.extend(['-i', path])
78    args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb']
79    args.extend(search_list)
80    args.append(dts_input)
81    command.Run('dtc', *args)
82    return dtb_output
83
84def GetInt(node, propname, default=None):
85    prop = node.props.get(propname)
86    if not prop:
87        return default
88    value = fdt32_to_cpu(prop.value)
89    if type(value) == type(list):
90        raise ValueError("Node '%s' property '%' has list value: expecting"
91                         "a single integer" % (node.name, propname))
92    return value
93
94def GetString(node, propname, default=None):
95    prop = node.props.get(propname)
96    if not prop:
97        return default
98    value = prop.value
99    if type(value) == type(list):
100        raise ValueError("Node '%s' property '%' has list value: expecting"
101                         "a single string" % (node.name, propname))
102    return value
103
104def GetBool(node, propname, default=False):
105    if propname in node.props:
106        return True
107    return default
108