1 # SPDX-License-Identifier: GPL-2.0+
2 # Copyright (c) 2016 Google, Inc
3 # Written by Simon Glass <sjg@chromium.org>
5 # Handle various things related to ELF images
8 from collections import namedtuple, OrderedDict
16 # This is enabled from control.py
19 Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak'])
22 def GetSymbols(fname, patterns):
23 """Get the symbols from an ELF file
26 fname: Filename of the ELF file to read
27 patterns: List of regex patterns to search for, each a string
30 None, if the file does not exist, or Dict:
32 value: Hex value of symbol
34 stdout = command.Output('objdump', '-t', fname, raise_on_error=False)
35 lines = stdout.splitlines()
37 re_syms = re.compile('|'.join(patterns))
43 if not line or not syms_started:
44 if 'SYMBOL TABLE' in line:
46 line = None # Otherwise code coverage complains about 'continue'
48 if re_syms and not re_syms.search(line):
51 space_pos = line.find(' ')
52 value, rest = line[:space_pos], line[space_pos + 1:]
54 parts = rest[7:].split()
55 section, size = parts[:2]
58 syms[name] = Symbol(section, int(value, 16), int(size,16),
62 def GetSymbolAddress(fname, sym_name):
63 """Get a value of a symbol from an ELF file
66 fname: Filename of the ELF file to read
67 patterns: List of regex patterns to search for, each a string
70 Symbol value (as an integer) or None if not found
72 syms = GetSymbols(fname, [sym_name])
73 sym = syms.get(sym_name)
78 def LookupAndWriteSymbols(elf_fname, entry, section):
79 """Replace all symbols in an entry with their correct values
81 The entry contents is updated so that values for referenced symbols will be
82 visible at run time. This is done by finding out the symbols positions in
83 the entry (using the ELF file) and replacing them with values from binman's
87 elf_fname: Filename of ELF image containing the symbol information for
89 entry: Entry to process
90 section: Section which can be used to lookup symbol values
92 fname = tools.GetInputFilename(elf_fname)
93 syms = GetSymbols(fname, ['image', 'binman'])
96 base = syms.get('__image_copy_start')
99 for name, sym in syms.iteritems():
100 if name.startswith('_binman'):
101 msg = ("Section '%s': Symbol '%s'\n in entry '%s'" %
102 (section.GetPath(), name, entry.GetPath()))
103 offset = sym.address - base.address
104 if offset < 0 or offset + sym.size > entry.contents_size:
105 raise ValueError('%s has offset %x (size %x) but the contents '
106 'size is %x' % (entry.GetPath(), offset,
107 sym.size, entry.contents_size))
113 raise ValueError('%s has size %d: only 4 and 8 are supported' %
116 # Look up the symbol in our entry tables.
117 value = section.LookupSymbol(name, sym.weak, msg)
118 if value is not None:
119 value += base.address
122 pack_string = pack_string.lower()
123 value_bytes = struct.pack(pack_string, value)
125 print('%s:\n insert %s, offset %x, value %x, length %d' %
126 (msg, name, offset, value, len(value_bytes)))
127 entry.data = (entry.data[:offset] + value_bytes +
128 entry.data[offset + sym.size:])