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 sys
  12 import tempfile
  13
  14 import command
  15 import tools
  16
  17 def 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
  32 def 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
  48 def 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
  84 def 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
  94 def 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
 104 def GetBool(node, propname, default=False):
 105     if propname in node.props:
 106         return True
 107     return default