#!/usr/bin/python # SPDX-License-Identifier: GPL-2.0+ # # Copyright (C) 2016 Google, Inc # Written by Simon Glass # # 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 u_boot_pylib import command from u_boot_pylib 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 fdt64_to_cpu(val): """Convert a device tree cell to an integer Args: val (list): Value to convert (list of 2 4-character strings representing the cell value) Return: int: A native-endian integer value """ return fdt32_to_cpu(val[0]) << 32 | fdt32_to_cpu(val[1]) 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.get_output_filename('source.dts') dtb_output = tools.get_output_filename('source.dtb') search_paths = [os.path.join(os.getcwd(), 'include')] root, _ = os.path.splitext(fname) cc, args = tools.get_target_compile_tool('cc') 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]) dtc, args = tools.get_target_compile_tool('dtc') args += ['-I', 'dts', '-o', dtb_output, '-O', 'dtb', '-W', 'no-unit_address_vs_reg'] args.extend(search_list) args.append(dts_input) 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 GetInt64(node, propname, default=None): """Get a 64-bit integer from a property Args: node (Node): Node object to read from propname (str): property name to read default (int): Default value to use if the node/property do not exist Returns: int: value read, or default if none Raises: ValueError: Property is not of the correct size """ prop = node.props.get(propname) if not prop: return default if not isinstance(prop.value, list) or len(prop.value) != 2: raise ValueError("Node '%s' property '%s' should be a list with 2 items for 64-bit values" % (node.name, propname)) value = fdt64_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 not prop.bytes: return '' if isinstance(value, list): raise ValueError("Node '%s' property '%s' has list value: expecting " "a single string" % (node.name, propname)) return value def GetStringList(node, propname, default=None): """Get a string list from a property Args: node (Node): Node object to read from propname (str): property name to read default (list of str): Default value to use if the node/property do not exist, or None Returns: String value read, or default if none """ prop = node.props.get(propname) if not prop: return default value = prop.value if not prop.bytes: return [] if not isinstance(value, list): strval = GetString(node, propname) return [strval] return value def GetArgs(node, propname): prop = node.props.get(propname) if not prop: raise ValueError(f"Node '{node.path}': Expected property '{propname}'") if prop.bytes: value = GetStringList(node, propname) else: value = [] if not value: args = [] elif len(value) == 1: args = value[0].split() else: args = value return args 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 GetBytes(node, propname, size, default=None): """Get a set of bytes from a property Args: node (Node): Node object to read from propname (str): property name to read size (int): Number of bytes to expect default (bytes): Default value or None Returns: bytes: Bytes value read, or default if none """ prop = node.props.get(propname) if not prop: return default if len(prop.bytes) != size: raise ValueError("Node '%s' property '%s' has length %d, expecting %d" % (node.name, propname, len(prop.bytes), size)) return prop.bytes 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 GetPhandleNameOffset(node, propname): """Get a <&phandle>, "string", value from a property Args: node: Node object to read from propname: property name to read Returns: tuple: Node object str int or None if the property does not exist """ prop = node.props.get(propname) if not prop: return None value = prop.bytes phandle = fdt32_to_cpu(value[:4]) node = node.GetFdt().LookupPhandle(phandle) name = '' for byte in value[4:]: if not byte: break name += chr(byte) val = fdt32_to_cpu(value[4 + len(name) + 1:]) return node, name, val 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)