u-boot/tools/dtoc/fdt_util.py
Simon Glass bf776679a7 patman: Move to absolute imports
At present patman sets the python path on startup so that it can access
the libraries it needs. If we convert to use absolute imports this is not
necessary.

Move patman to use absolute imports. This requires changes in tools which
use the patman libraries (which is most of them).

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-04-26 14:25:21 -06:00

206 lines
5.9 KiB
Python

#!/usr/bin/python
# SPDX-License-Identifier: GPL-2.0+
#
# Copyright (C) 2016 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
# Utility functions for reading from a device tree. Once the upstream pylibfdt
# implementation advances far enough, we should be able to drop these.
import os
import struct
import sys
import tempfile
from patman import command
from patman import tools
def fdt32_to_cpu(val):
"""Convert a device tree cell to an integer
Args:
Value to convert (4-character string representing the cell value)
Return:
A native-endian integer value
"""
return struct.unpack('>I', val)[0]
def fdt_cells_to_cpu(val, cells):
"""Convert one or two cells to a long integer
Args:
Value to convert (array of one or more 4-character strings)
Return:
A native-endian integer value
"""
if not cells:
return 0
out = int(fdt32_to_cpu(val[0]))
if cells == 2:
out = out << 32 | fdt32_to_cpu(val[1])
return out
def EnsureCompiled(fname, tmpdir=None, capture_stderr=False):
"""Compile an fdt .dts source file into a .dtb binary blob if needed.
Args:
fname: Filename (if .dts it will be compiled). It not it will be
left alone
tmpdir: Temporary directory for output files, or None to use the
tools-module output directory
Returns:
Filename of resulting .dtb file
"""
_, ext = os.path.splitext(fname)
if ext != '.dts':
return fname
if tmpdir:
dts_input = os.path.join(tmpdir, 'source.dts')
dtb_output = os.path.join(tmpdir, 'source.dtb')
else:
dts_input = tools.GetOutputFilename('source.dts')
dtb_output = tools.GetOutputFilename('source.dtb')
search_paths = [os.path.join(os.getcwd(), 'include')]
root, _ = os.path.splitext(fname)
args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
args += ['-Ulinux']
for path in search_paths:
args.extend(['-I', path])
args += ['-o', dts_input, fname]
command.Run('cc', *args)
# If we don't have a directory, put it in the tools tempdir
search_list = []
for path in search_paths:
search_list.extend(['-i', path])
args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb',
'-W', 'no-unit_address_vs_reg']
args.extend(search_list)
args.append(dts_input)
dtc = os.environ.get('DTC') or 'dtc'
command.Run(dtc, *args, capture_stderr=capture_stderr)
return dtb_output
def GetInt(node, propname, default=None):
"""Get an integer from a property
Args:
node: Node object to read from
propname: property name to read
default: Default value to use if the node/property do not exist
Returns:
Integer value read, or default if none
"""
prop = node.props.get(propname)
if not prop:
return default
if isinstance(prop.value, list):
raise ValueError("Node '%s' property '%s' has list value: expecting "
"a single integer" % (node.name, propname))
value = fdt32_to_cpu(prop.value)
return value
def GetString(node, propname, default=None):
"""Get a string from a property
Args:
node: Node object to read from
propname: property name to read
default: Default value to use if the node/property do not exist
Returns:
String value read, or default if none
"""
prop = node.props.get(propname)
if not prop:
return default
value = prop.value
if isinstance(value, list):
raise ValueError("Node '%s' property '%s' has list value: expecting "
"a single string" % (node.name, propname))
return value
def GetBool(node, propname, default=False):
"""Get an boolean from a property
Args:
node: Node object to read from
propname: property name to read
default: Default value to use if the node/property do not exist
Returns:
Boolean value read, or default if none (if you set this to True the
function will always return True)
"""
if propname in node.props:
return True
return default
def GetByte(node, propname, default=None):
"""Get an byte from a property
Args:
node: Node object to read from
propname: property name to read
default: Default value to use if the node/property do not exist
Returns:
Byte value read, or default if none
"""
prop = node.props.get(propname)
if not prop:
return default
value = prop.value
if isinstance(value, list):
raise ValueError("Node '%s' property '%s' has list value: expecting "
"a single byte" % (node.name, propname))
if len(value) != 1:
raise ValueError("Node '%s' property '%s' has length %d, expecting %d" %
(node.name, propname, len(value), 1))
return ord(value[0])
def GetPhandleList(node, propname):
"""Get a list of phandles from a property
Args:
node: Node object to read from
propname: property name to read
Returns:
List of phandles read, each an integer
"""
prop = node.props.get(propname)
if not prop:
return None
value = prop.value
if not isinstance(value, list):
value = [value]
return [fdt32_to_cpu(v) for v in value]
def GetDatatype(node, propname, datatype):
"""Get a value of a given type from a property
Args:
node: Node object to read from
propname: property name to read
datatype: Type to read (str or int)
Returns:
value read, or None if none
Raises:
ValueError if datatype is not str or int
"""
if datatype == str:
return GetString(node, propname)
elif datatype == int:
return GetInt(node, propname)
raise ValueError("fdt_util internal error: Unknown data type '%s'" %
datatype)