Binman needs to be able to update the contents of an ELF file after it has been build. To support this, add a function to locate the position of a symbol's contents within the file.
Fix the comments on bss_data.c and Symbol while we are here.
Signed-off-by: Simon Glass sjg@chromium.org ---
tools/binman/elf.py | 53 ++++++++++++++++++++++++++++++-- tools/binman/elf_test.py | 37 ++++++++++++++++++++++ tools/binman/test/Makefile | 5 ++- tools/binman/test/bss_data.c | 2 +- tools/binman/test/embed_data.c | 16 ++++++++++ tools/binman/test/embed_data.lds | 23 ++++++++++++++ 6 files changed, 131 insertions(+), 5 deletions(-) create mode 100644 tools/binman/test/embed_data.c create mode 100644 tools/binman/test/embed_data.lds
diff --git a/tools/binman/elf.py b/tools/binman/elf.py index 03b49d7163c..4aca4f847ce 100644 --- a/tools/binman/elf.py +++ b/tools/binman/elf.py @@ -24,7 +24,14 @@ try: except: # pragma: no cover ELF_TOOLS = False
-Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak']) +# Information about an EFL symbol: +# section (str): Name of the section containing this symbol +# address (int): Address of the symbol (its value) +# size (int): Size of the symbol in bytes +# weak (bool): True if the symbol is weak +# offset (int or None): Offset of the symbol's data in the ELF file, or None if +# not known +Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak', 'offset'])
# Information about an ELF file: # data: Extracted program contents of ELF file (this would be loaded by an @@ -71,8 +78,48 @@ def GetSymbols(fname, patterns): section, size = parts[:2] if len(parts) > 2: name = parts[2] if parts[2] != '.hidden' else parts[3] - syms[name] = Symbol(section, int(value, 16), int(size,16), - flags[1] == 'w') + syms[name] = Symbol(section, int(value, 16), int(size, 16), + flags[1] == 'w', None) + + # Sort dict by address + return OrderedDict(sorted(syms.items(), key=lambda x: x[1].address)) + +def GetSymbolFileOffset(fname, patterns): + """Get the symbols from an ELF file + + Args: + fname: Filename of the ELF file to read + patterns: List of regex patterns to search for, each a string + + Returns: + None, if the file does not exist, or Dict: + key: Name of symbol + value: Hex value of symbol + """ + def _GetFileOffset(elf, addr): + for seg in elf.iter_segments(): + seg_end = seg['p_vaddr'] + seg['p_filesz'] + if seg.header['p_type'] == 'PT_LOAD': + if addr >= seg['p_vaddr'] and addr < seg_end: + return addr - seg['p_vaddr'] + seg['p_offset'] + + if not ELF_TOOLS: + raise ValueError('Python elftools package is not available') + + syms = {} + with open(fname, 'rb') as fd: + elf = ELFFile(fd) + + re_syms = re.compile('|'.join(patterns)) + for section in elf.iter_sections(): + if isinstance(section, SymbolTableSection): + for symbol in section.iter_symbols(): + if not re_syms or re_syms.search(symbol.name): + addr = symbol.entry['st_value'] + syms[symbol.name] = Symbol( + section.name, addr, symbol.entry['st_size'], + symbol.entry['st_info']['bind'] == 'STB_WEAK', + _GetFileOffset(elf, addr))
# Sort dict by address return OrderedDict(sorted(syms.items(), key=lambda x: x[1].address)) diff --git a/tools/binman/elf_test.py b/tools/binman/elf_test.py index bcccd78c0a1..ac69a95b654 100644 --- a/tools/binman/elf_test.py +++ b/tools/binman/elf_test.py @@ -6,6 +6,7 @@
import os import shutil +import struct import sys import tempfile import unittest @@ -221,6 +222,42 @@ class TestElf(unittest.TestCase): elf.DecodeElf(data, load + 2)) shutil.rmtree(outdir)
+ def testEmbedData(self): + """Test for the GetSymbolFileOffset() function""" + if not elf.ELF_TOOLS: + self.skipTest('Python elftools not available') + + fname = self.ElfTestFile('embed_data') + offset = elf.GetSymbolFileOffset(fname, ['embed_start', 'embed_end']) + start = offset['embed_start'].offset + end = offset['embed_end'].offset + data = tools.ReadFile(fname) + embed_data = data[start:end] + expect = struct.pack('<III', 0x1234, 0x5678, 0) + self.assertEqual(expect, embed_data) + + def testEmbedFail(self): + """Test calling GetSymbolFileOffset() without elftools""" + try: + old_val = elf.ELF_TOOLS + elf.ELF_TOOLS = False + fname = self.ElfTestFile('embed_data') + with self.assertRaises(ValueError) as e: + elf.GetSymbolFileOffset(fname, ['embed_start', 'embed_end']) + self.assertIn('Python elftools package is not available', + str(e.exception)) + finally: + elf.ELF_TOOLS = old_val + + def testEmbedDataNoSym(self): + """Test for GetSymbolFileOffset() getting no symbols""" + if not elf.ELF_TOOLS: + self.skipTest('Python elftools not available') + + fname = self.ElfTestFile('embed_data') + offset = elf.GetSymbolFileOffset(fname, ['missing_sym']) + self.assertEqual({}, offset) +
if __name__ == '__main__': unittest.main() diff --git a/tools/binman/test/Makefile b/tools/binman/test/Makefile index 0b19b7d9935..6e6cc6de491 100644 --- a/tools/binman/test/Makefile +++ b/tools/binman/test/Makefile @@ -31,7 +31,7 @@ LDS_BINMAN_X86 := -T $(SRC)u_boot_binman_syms_x86.lds
TARGETS = u_boot_ucode_ptr u_boot_no_ucode_ptr bss_data \ u_boot_binman_syms u_boot_binman_syms.bin u_boot_binman_syms_bad \ - u_boot_binman_syms_size u_boot_binman_syms_x86 + u_boot_binman_syms_size u_boot_binman_syms_x86 embed_data
all: $(TARGETS)
@@ -44,6 +44,9 @@ u_boot_ucode_ptr: u_boot_ucode_ptr.c bss_data: CFLAGS += $(SRC)bss_data.lds bss_data: bss_data.c
+embed_data: CFLAGS += $(SRC)embed_data.lds +embed_data: embed_data.c + u_boot_binman_syms.bin: u_boot_binman_syms $(OBJCOPY) -O binary $< -R .note.gnu.build-id $@
diff --git a/tools/binman/test/bss_data.c b/tools/binman/test/bss_data.c index 79537c31b65..4f9b64cef9e 100644 --- a/tools/binman/test/bss_data.c +++ b/tools/binman/test/bss_data.c @@ -2,7 +2,7 @@ /* * Copyright (c) 2016 Google, Inc * - * Simple program to create a _dt_ucode_base_size symbol which can be read + * Simple program to create a bss_data region so the symbol can be read * by binutils. This is used by binman tests. */
diff --git a/tools/binman/test/embed_data.c b/tools/binman/test/embed_data.c new file mode 100644 index 00000000000..47d8c38248c --- /dev/null +++ b/tools/binman/test/embed_data.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2021 Google LLC + * + * Simple program including some embedded data that can be accessed by binman. + * This is used by binman tests. + */ + +int first[10] = {1}; +int embed[3] __attribute__((section(".embed"))) = {0x1234, 0x5678}; +int second[10] = {1}; + +int main(void) +{ + return 0; +} diff --git a/tools/binman/test/embed_data.lds b/tools/binman/test/embed_data.lds new file mode 100644 index 00000000000..908bf66c294 --- /dev/null +++ b/tools/binman/test/embed_data.lds @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright 2021 Google LLC + */ + +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(_start) + +SECTIONS +{ + _start = .; + __data_start = .; + .data : + { + . = ALIGN(32); + embed_start = .; + *(.embed*) + embed_end = .; + . = ALIGN(32); + *(.data*) + } +}