1 # Copyright (c) 2016 Google, Inc
2 # Written by Simon Glass <sjg@chromium.org>
4 # SPDX-License-Identifier: GPL-2.0+
6 # Handle various things related to ELF images
9 from collections import namedtuple, OrderedDict
17 # This is enabled from control.py
20 Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak'])
23 def GetSymbols(fname, patterns):
24 """Get the symbols from an ELF file
27 fname: Filename of the ELF file to read
28 patterns: List of regex patterns to search for, each a string
31 None, if the file does not exist, or Dict:
33 value: Hex value of symbol
35 stdout = command.Output('objdump', '-t', fname, raise_on_error=False)
36 lines = stdout.splitlines()
38 re_syms = re.compile('|'.join(patterns))
44 if not line or not syms_started:
45 if 'SYMBOL TABLE' in line:
47 line = None # Otherwise code coverage complains about 'continue'
49 if re_syms and not re_syms.search(line):
52 space_pos = line.find(' ')
53 value, rest = line[:space_pos], line[space_pos + 1:]
55 parts = rest[7:].split()
56 section, size = parts[:2]
59 syms[name] = Symbol(section, int(value, 16), int(size,16),
63 def GetSymbolAddress(fname, sym_name):
64 """Get a value of a symbol from an ELF file
67 fname: Filename of the ELF file to read
68 patterns: List of regex patterns to search for, each a string
71 Symbol value (as an integer) or None if not found
73 syms = GetSymbols(fname, [sym_name])
74 sym = syms.get(sym_name)
79 def LookupAndWriteSymbols(elf_fname, entry, image):
80 """Replace all symbols in an entry with their correct values
82 The entry contents is updated so that values for referenced symbols will be
83 visible at run time. This is done by finding out the symbols positions in
84 the entry (using the ELF file) and replacing them with values from binman's
88 elf_fname: Filename of ELF image containing the symbol information for
90 entry: Entry to process
91 image: Image which can be used to lookup symbol values
93 fname = tools.GetInputFilename(elf_fname)
94 syms = GetSymbols(fname, ['image', 'binman'])
97 base = syms.get('__image_copy_start')
100 for name, sym in syms.iteritems():
101 if name.startswith('_binman'):
102 msg = ("Image '%s': Symbol '%s'\n in entry '%s'" %
103 (image.GetPath(), name, entry.GetPath()))
104 offset = sym.address - base.address
105 if offset < 0 or offset + sym.size > entry.contents_size:
106 raise ValueError('%s has offset %x (size %x) but the contents '
107 'size is %x' % (entry.GetPath(), offset,
108 sym.size, entry.contents_size))
114 raise ValueError('%s has size %d: only 4 and 8 are supported' %
117 # Look up the symbol in our entry tables.
118 value = image.LookupSymbol(name, sym.weak, msg)
119 if value is not None:
120 value += base.address
123 pack_string = pack_string.lower()
124 value_bytes = struct.pack(pack_string, value)
126 print('%s:\n insert %s, offset %x, value %x, length %d' %
127 (msg, name, offset, value, len(value_bytes)))
128 entry.data = (entry.data[:offset] + value_bytes +
129 entry.data[offset + sym.size:])