From b50e5611a6b5dff4bc2ae47d332ba0d046e2a782 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Mon, 13 Nov 2017 18:54:54 -0700 Subject: [PATCH] binman: Add a function to read ELF symbols In some cases we need to read symbols from U-Boot. At present we have a a few cases which does this via 'nm' and 'grep'. It is better to use objdump since that tells us the size of the symbols and also whether it is weak or not. Add a new module which reads ELF information from files. Update existing uses of 'nm' to use this module. Signed-off-by: Simon Glass --- tools/binman/binman.py | 3 +- tools/binman/elf.py | 77 +++++++++++++++++++++++++++++ tools/binman/elf_test.py | 32 ++++++++++++ tools/binman/etype/u_boot_spl_bss_pad.py | 7 +-- tools/binman/etype/u_boot_with_ucode_ptr.py | 9 ++-- tools/binman/ftest.py | 7 +++ tools/binman/test/bss_data.c | 2 +- tools/binman/test/u_boot_ucode_ptr.c | 2 +- 8 files changed, 128 insertions(+), 11 deletions(-) create mode 100644 tools/binman/elf.py create mode 100644 tools/binman/elf_test.py diff --git a/tools/binman/binman.py b/tools/binman/binman.py index 3ccf25f..81a613d 100755 --- a/tools/binman/binman.py +++ b/tools/binman/binman.py @@ -33,6 +33,7 @@ import control def RunTests(): """Run the functional tests and any embedded doctests""" + import elf_test import entry_test import fdt_test import ftest @@ -50,7 +51,7 @@ def RunTests(): # 'entry' module. suite = unittest.TestLoader().loadTestsFromTestCase(entry_test.TestEntry) suite.run(result) - for module in (ftest.TestFunctional, fdt_test.TestFdt): + for module in (ftest.TestFunctional, fdt_test.TestFdt, elf_test.TestElf): suite = unittest.TestLoader().loadTestsFromTestCase(module) suite.run(result) diff --git a/tools/binman/elf.py b/tools/binman/elf.py new file mode 100644 index 0000000..97208b1 --- /dev/null +++ b/tools/binman/elf.py @@ -0,0 +1,77 @@ +# Copyright (c) 2016 Google, Inc +# Written by Simon Glass +# +# SPDX-License-Identifier: GPL-2.0+ +# +# Handle various things related to ELF images +# + +from collections import namedtuple, OrderedDict +import command +import os +import re +import struct + +import tools + +Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak']) + +# Used for tests which don't have an ELF file to read +ignore_missing_files = False + + +def GetSymbols(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 + """ + stdout = command.Output('objdump', '-t', fname, raise_on_error=False) + lines = stdout.splitlines() + if patterns: + re_syms = re.compile('|'.join(patterns)) + else: + re_syms = None + syms = {} + syms_started = False + for line in lines: + if not line or not syms_started: + if 'SYMBOL TABLE' in line: + syms_started = True + line = None # Otherwise code coverage complains about 'continue' + continue + if re_syms and not re_syms.search(line): + continue + + space_pos = line.find(' ') + value, rest = line[:space_pos], line[space_pos + 1:] + flags = rest[:7] + parts = rest[7:].split() + section, size = parts[:2] + if len(parts) > 2: + name = parts[2] + syms[name] = Symbol(section, int(value, 16), int(size,16), + flags[1] == 'w') + return syms + +def GetSymbolAddress(fname, sym_name): + """Get a value of a symbol 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: + Symbol value (as an integer) or None if not found + """ + syms = GetSymbols(fname, [sym_name]) + sym = syms.get(sym_name) + if not sym: + return None + return sym.address diff --git a/tools/binman/elf_test.py b/tools/binman/elf_test.py new file mode 100644 index 0000000..dca7bc5 --- /dev/null +++ b/tools/binman/elf_test.py @@ -0,0 +1,32 @@ +# +# Copyright (c) 2017 Google, Inc +# Written by Simon Glass +# +# SPDX-License-Identifier: GPL-2.0+ +# +# Test for the elf module + +import os +import sys +import unittest + +import elf + +binman_dir = os.path.dirname(os.path.realpath(sys.argv[0])) +fname = os.path.join(binman_dir, 'test', 'u_boot_ucode_ptr') + +class TestElf(unittest.TestCase): + def testAllSymbols(self): + syms = elf.GetSymbols(fname, []) + self.assertIn('.ucode', syms) + + def testRegexSymbols(self): + syms = elf.GetSymbols(fname, ['ucode']) + self.assertIn('.ucode', syms) + syms = elf.GetSymbols(fname, ['missing']) + self.assertNotIn('.ucode', syms) + syms = elf.GetSymbols(fname, ['missing', 'ucode']) + self.assertIn('.ucode', syms) + +if __name__ == '__main__': + unittest.main() diff --git a/tools/binman/etype/u_boot_spl_bss_pad.py b/tools/binman/etype/u_boot_spl_bss_pad.py index c005f28..c37f61d 100644 --- a/tools/binman/etype/u_boot_spl_bss_pad.py +++ b/tools/binman/etype/u_boot_spl_bss_pad.py @@ -9,6 +9,7 @@ # import command +import elf from entry import Entry from blob import Entry_blob import tools @@ -19,8 +20,8 @@ class Entry_u_boot_spl_bss_pad(Entry_blob): def ObtainContents(self): fname = tools.GetInputFilename('spl/u-boot-spl') - args = [['nm', fname], ['grep', '__bss_size']] - out = command.RunPipe(args, capture=True).stdout.splitlines() - bss_size = int(out[0].split()[0], 16) + bss_size = elf.GetSymbolAddress(fname, '__bss_size') + if not bss_size: + self.Raise('Expected __bss_size symbol in spl/u-boot-spl') self.data = chr(0) * bss_size self.contents_size = bss_size diff --git a/tools/binman/etype/u_boot_with_ucode_ptr.py b/tools/binman/etype/u_boot_with_ucode_ptr.py index 6f01adb..99b4371 100644 --- a/tools/binman/etype/u_boot_with_ucode_ptr.py +++ b/tools/binman/etype/u_boot_with_ucode_ptr.py @@ -9,6 +9,7 @@ import struct import command +import elf from entry import Entry from blob import Entry_blob import fdt_util @@ -31,11 +32,9 @@ class Entry_u_boot_with_ucode_ptr(Entry_blob): def ObtainContents(self): # Figure out where to put the microcode pointer fname = tools.GetInputFilename(self.elf_fname) - args = [['nm', fname], ['grep', '-w', '_dt_ucode_base_size']] - out = (command.RunPipe(args, capture=True, raise_on_error=False). - stdout.splitlines()) - if len(out) == 1: - self.target_pos = int(out[0].split()[0], 16) + sym = elf.GetSymbolAddress(fname, '_dt_ucode_base_size') + if sym: + self.target_pos = sym elif not fdt_util.GetBool(self._node, 'optional-ucode'): self.Raise('Cannot locate _dt_ucode_base_size symbol in u-boot') diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py index 9083143..c815578 100644 --- a/tools/binman/ftest.py +++ b/tools/binman/ftest.py @@ -835,6 +835,13 @@ class TestFunctional(unittest.TestCase): data = self._DoReadFile('47_spl_bss_pad.dts') self.assertEqual(U_BOOT_SPL_DATA + (chr(0) * 10) + U_BOOT_DATA, data) + with open(self.TestFile('u_boot_ucode_ptr')) as fd: + TestFunctional._MakeInputFile('spl/u-boot-spl', fd.read()) + with self.assertRaises(ValueError) as e: + data = self._DoReadFile('47_spl_bss_pad.dts') + self.assertIn('Expected __bss_size symbol in spl/u-boot-spl', + str(e.exception)) + def testPackStart16Spl(self): """Test that an image with an x86 start16 region can be created""" data = self._DoReadFile('48_x86-start16-spl.dts') diff --git a/tools/binman/test/bss_data.c b/tools/binman/test/bss_data.c index f865a9d..e0305c3 100644 --- a/tools/binman/test/bss_data.c +++ b/tools/binman/test/bss_data.c @@ -4,7 +4,7 @@ * SPDX-License-Identifier: GPL-2.0+ * * Simple program to create a _dt_ucode_base_size symbol which can be read - * by 'nm'. This is used by binman tests. + * by binutils. This is used by binman tests. */ int bss_data[10]; diff --git a/tools/binman/test/u_boot_ucode_ptr.c b/tools/binman/test/u_boot_ucode_ptr.c index 24f349f..734d54f 100644 --- a/tools/binman/test/u_boot_ucode_ptr.c +++ b/tools/binman/test/u_boot_ucode_ptr.c @@ -4,7 +4,7 @@ * SPDX-License-Identifier: GPL-2.0+ * * Simple program to create a _dt_ucode_base_size symbol which can be read - * by 'nm'. This is used by binman tests. + * by binutils. This is used by binman tests. */ static unsigned long _dt_ucode_base_size[2]