tools/dtoc/fdt_util.py

   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
   9 import os
  10 import struct
  11 import tempfile
  12
  13 import command
  14 import tools
  15
  16 def 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
  27 def 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
  63 def 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
  73 def 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
  83 def GetBool(node, propname, default=False):
  84     if propname in node.props:
  85         return True
  86     return default