objdump
(1g)
Name
objdump - display information from object files.
Synopsis
objdump [-a|--archive-headers]
[-b bfdname|--target=bfdname]
[-C|--demangle[=style] ]
[-d|--disassemble]
[-D|--disassemble-all]
[-z|--disassemble-zeroes]
[-EB|-EL|--endian={big | little }]
[-f|--file-headers]
[-F|--file-offsets]
[--file-start-context]
[-g|--debugging]
[-e|--debugging-tags]
[-h|--section-headers|--headers]
[-i|--info]
[-j section|--section=section]
[-l|--line-numbers]
[-S|--source]
[-m machine|--architecture=machine]
[-M options|--disassembler-options=options]
[-p|--private-headers]
[-P options|--private=options]
[-r|--reloc]
[-R|--dynamic-reloc]
[-s|--full-contents]
[-W[lLiaprmfFsoRt]|
--dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index]]
[-G|--stabs]
[-t|--syms]
[-T|--dynamic-syms]
[-x|--all-headers]
[-w|--wide]
[--start-address=address]
[--stop-address=address]
[--prefix-addresses]
[--[no-]show-raw-insn]
[--adjust-vma=offset]
[--special-syms]
[--prefix=prefix]
[--prefix-strip=level]
[--insn-width=width]
[-V|--version]
[-H|--help]
objfile...
Description
GNU Development Tools OBJDUMP(1)
NAME
objdump - display information from object files.
SYNOPSIS
objdump [-a|--archive-headers]
[-b bfdname|--target=bfdname]
[-C|--demangle[=style] ]
[-d|--disassemble]
[-D|--disassemble-all]
[-z|--disassemble-zeroes]
[-EB|-EL|--endian={big | little }]
[-f|--file-headers]
[-F|--file-offsets]
[--file-start-context]
[-g|--debugging]
[-e|--debugging-tags]
[-h|--section-headers|--headers]
[-i|--info]
[-j section|--section=section]
[-l|--line-numbers]
[-S|--source]
[-m machine|--architecture=machine]
[-M options|--disassembler-options=options]
[-p|--private-headers]
[-P options|--private=options]
[-r|--reloc]
[-R|--dynamic-reloc]
[-s|--full-contents]
[-W[lLiaprmfFsoRt]|
--dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index]]
[-G|--stabs]
[-t|--syms]
[-T|--dynamic-syms]
[-x|--all-headers]
[-w|--wide]
[--start-address=address]
[--stop-address=address]
[--prefix-addresses]
[--[no-]show-raw-insn]
[--adjust-vma=offset]
[--special-syms]
[--prefix=prefix]
[--prefix-strip=level]
[--insn-width=width]
[-V|--version]
[-H|--help]
objfile...
DESCRIPTION
objdump displays information about one or more object files.
The options control what particular information to display.
This information is mostly useful to programmers who are
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GNU Development Tools OBJDUMP(1)
working on the compilation tools, as opposed to programmers
who just want their program to compile and work.
objfile... are the object files to be examined. When you
specify archives, objdump shows information on each of the
member object files.
OPTIONS
The long and short forms of options, shown here as
alternatives, are equivalent. At least one option from the
list
-a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x
must be given.
-a
--archive-header
If any of the objfile files are archives, display the
archive header information (in a format similar to ls
-l). Besides the information you could list with ar tv,
objdump -a shows the object file format of each archive
member.
--adjust-vma=offset
When dumping information, first add offset to all the
section addresses. This is useful if the section
addresses do not correspond to the symbol table, which
can happen when putting sections at particular addresses
when using a format which can not represent section
addresses, such as a.out.
-b bfdname
--target=bfdname
Specify that the object-code format for the object files
is bfdname. This option may not be necessary; objdump
can automatically recognize many formats.
For example,
objdump -b oasys -m vax -h fu.o
displays summary information from the section headers
(-h) of fu.o, which is explicitly identified (-m) as a
VAX object file in the format produced by Oasys
compilers. You can list the formats available with the
-i option.
-C
--demangle[=style]
Decode (demangle) low-level symbol names into user-level
names. Besides removing any initial underscore
prepended by the system, this makes C++ function names
readable. Different compilers have different mangling
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styles. The optional demangling style argument can be
used to choose an appropriate demangling style for your
compiler.
-g
--debugging
Display debugging information. This attempts to parse
STABS and IEEE debugging format information stored in
the file and print it out using a C like syntax. If
neither of these formats are found this option falls
back on the -W option to print any DWARF information in
the file.
-e
--debugging-tags
Like -g, but the information is generated in a format
compatible with ctags tool.
-d
--disassemble
Display the assembler mnemonics for the machine
instructions from objfile. This option only
disassembles those sections which are expected to
contain instructions.
-D
--disassemble-all
Like -d, but disassemble the contents of all sections,
not just those expected to contain instructions.
If the target is an ARM architecture this switch also
has the effect of forcing the disassembler to decode
pieces of data found in code sections as if they were
instructions.
--prefix-addresses
When disassembling, print the complete address on each
line. This is the older disassembly format.
-EB
-EL
--endian={big|little}
Specify the endianness of the object files. This only
affects disassembly. This can be useful when
disassembling a file format which does not describe
endianness information, such as S-records.
-f
--file-headers
Display summary information from the overall header of
each of the objfile files.
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-F
--file-offsets
When disassembling sections, whenever a symbol is
displayed, also display the file offset of the region of
data that is about to be dumped. If zeroes are being
skipped, then when disassembly resumes, tell the user
how many zeroes were skipped and the file offset of the
location from where the disassembly resumes. When
dumping sections, display the file offset of the
location from where the dump starts.
--file-start-context
Specify that when displaying interlisted source
code/disassembly (assumes -S) from a file that has not
yet been displayed, extend the context to the start of
the file.
-h
--section-headers
--headers
Display summary information from the section headers of
the object file.
File segments may be relocated to nonstandard addresses,
for example by using the -Ttext, -Tdata, or -Tbss
options to ld. However, some object file formats, such
as a.out, do not store the starting address of the file
segments. In those situations, although ld relocates
the sections correctly, using objdump -h to list the
file section headers cannot show the correct addresses.
Instead, it shows the usual addresses, which are
implicit for the target.
-H
--help
Print a summary of the options to objdump and exit.
-i
--info
Display a list showing all architectures and object
formats available for specification with -b or -m.
-j name
--section=name
Display information only for section name.
-l
--line-numbers
Label the display (using debugging information) with the
filename and source line numbers corresponding to the
object code or relocs shown. Only useful with -d, -D,
or -r.
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-m machine
--architecture=machine
Specify the architecture to use when disassembling
object files. This can be useful when disassembling
object files which do not describe architecture
information, such as S-records. You can list the
available architectures with the -i option.
If the target is an ARM architecture then this switch
has an additional effect. It restricts the disassembly
to only those instructions supported by the architecture
specified by machine. If it is necessary to use this
switch because the input file does not contain any
architecture information, but it is also desired to
disassemble all the instructions use -marm.
-M options
--disassembler-options=options
Pass target specific information to the disassembler.
Only supported on some targets. If it is necessary to
specify more than one disassembler option then multiple
-M options can be used or can be placed together into a
comma separated list.
If the target is an ARM architecture then this switch
can be used to select which register name set is used
during disassembler. Specifying -M reg-names-std (the
default) will select the register names as used in ARM's
instruction set documentation, but with register 13
called 'sp', register 14 called 'lr' and register 15
called 'pc'. Specifying -M reg-names-apcs will select
the name set used by the ARM Procedure Call Standard,
whilst specifying -M reg-names-raw will just use r
followed by the register number.
There are also two variants on the APCS register naming
scheme enabled by -M reg-names-atpcs and -M reg-names-
special-atpcs which use the ARM/Thumb Procedure Call
Standard naming conventions. (Either with the normal
register names or the special register names).
This option can also be used for ARM architectures to
force the disassembler to interpret all instructions as
Thumb instructions by using the switch
--disassembler-options=force-thumb. This can be useful
when attempting to disassemble thumb code produced by
other compilers.
For the x86, some of the options duplicate functions of
the -m switch, but allow finer grained control.
Multiple selections from the following may be specified
as a comma separated string. x86-64, i386 and i8086
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select disassembly for the given architecture. intel
and att select between intel syntax mode and AT&T syntax
mode. intel-mnemonic and att-mnemonic select between
intel mnemonic mode and AT&T mnemonic mode. intel-
mnemonic implies intel and att-mnemonic implies att.
addr64, addr32, addr16, data32 and data16 specify the
default address size and operand size. These four
options will be overridden if x86-64, i386 or i8086
appear later in the option string. Lastly, suffix, when
in AT&T mode, instructs the disassembler to print a
mnemonic suffix even when the suffix could be inferred
by the operands.
For PowerPC, booke controls the disassembly of BookE
instructions. 32 and 64 select PowerPC and PowerPC64
disassembly, respectively. e300 selects disassembly for
the e300 family. 440 selects disassembly for the
PowerPC 440. ppcps selects disassembly for the paired
single instructions of the PPC750CL.
For MIPS, this option controls the printing of
instruction mnemonic names and register names in
disassembled instructions. Multiple selections from the
following may be specified as a comma separated string,
and invalid options are ignored:
"no-aliases"
Print the 'raw' instruction mnemonic instead of some
pseudo instruction mnemonic. I.e., print 'daddu' or
'or' instead of 'move', 'sll' instead of 'nop', etc.
"gpr-names=ABI"
Print GPR (general-purpose register) names as
appropriate for the specified ABI. By default, GPR
names are selected according to the ABI of the
binary being disassembled.
"fpr-names=ABI"
Print FPR (floating-point register) names as
appropriate for the specified ABI. By default, FPR
numbers are printed rather than names.
"cp0-names=ARCH"
Print CP0 (system control coprocessor; coprocessor
0) register names as appropriate for the CPU or
architecture specified by ARCH. By default, CP0
register names are selected according to the
architecture and CPU of the binary being
disassembled.
"hwr-names=ARCH"
Print HWR (hardware register, used by the "rdhwr"
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instruction) names as appropriate for the CPU or
architecture specified by ARCH. By default, HWR
names are selected according to the architecture and
CPU of the binary being disassembled.
"reg-names=ABI"
Print GPR and FPR names as appropriate for the
selected ABI.
"reg-names=ARCH"
Print CPU-specific register names (CP0 register and
HWR names) as appropriate for the selected CPU or
architecture.
For any of the options listed above, ABI or ARCH may be
specified as numeric to have numbers printed rather than
names, for the selected types of registers. You can
list the available values of ABI and ARCH using the
--help option.
For VAX, you can specify function entry addresses with
-M entry:0xf00ba. You can use this multiple times to
properly disassemble VAX binary files that don't contain
symbol tables (like ROM dumps). In these cases, the
function entry mask would otherwise be decoded as VAX
instructions, which would probably lead the rest of the
function being wrongly disassembled.
-p
--private-headers
Print information that is specific to the object file
format. The exact information printed depends upon the
object file format. For some object file formats, no
additional information is printed.
-P options
--private=options
Print information that is specific to the object file
format. The argument options is a comma separated list
that depends on the format (the lists of options is
displayed with the help).
For XCOFF, the available options are: header, aout,
sections, syms, relocs, lineno, loader, except, typchk,
traceback and toc.
-r
--reloc
Print the relocation entries of the file. If used with
-d or -D, the relocations are printed interspersed with
the disassembly.
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-R
--dynamic-reloc
Print the dynamic relocation entries of the file. This
is only meaningful for dynamic objects, such as certain
types of shared libraries. As for -r, if used with -d
or -D, the relocations are printed interspersed with the
disassembly.
-s
--full-contents
Display the full contents of any sections requested. By
default all non-empty sections are displayed.
-S
--source
Display source code intermixed with disassembly, if
possible. Implies -d.
--prefix=prefix
Specify prefix to add to the absolute paths when used
with -S.
--prefix-strip=level
Indicate how many initial directory names to strip off
the hardwired absolute paths. It has no effect without
--prefix=prefix.
--show-raw-insn
When disassembling instructions, print the instruction
in hex as well as in symbolic form. This is the default
except when --prefix-addresses is used.
--no-show-raw-insn
When disassembling instructions, do not print the
instruction bytes. This is the default when
--prefix-addresses is used.
--insn-width=width
Display width bytes on a single line when disassembling
instructions.
-W[lLiaprmfFsoRt]
--dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index]
Displays the contents of the debug sections in the file,
if any are present. If one of the optional letters or
words follows the switch then only data found in those
specific sections will be dumped.
Note that there is no single letter option to display
the content of trace sections or .gdb_index.
Note: the output from the =info option can also be
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affected by the options --dwarf-depth, the --dwarf-start
and the --dwarf-check.
--dwarf-depth=n
Limit the dump of the ".debug_info" section to n
children. This is only useful with --dwarf=info. The
default is to print all DIEs; the special value 0 for n
will also have this effect.
With a non-zero value for n, DIEs at or deeper than n
levels will not be printed. The range for n is zero-
based.
--dwarf-start=n
Print only DIEs beginning with the DIE numbered n. This
is only useful with --dwarf=info.
If specified, this option will suppress printing of any
header information and all DIEs before the DIE numbered
n. Only siblings and children of the specified DIE will
be printed.
This can be used in conjunction with --dwarf-depth.
--dwarf-check
Enable additional checks for consistency of Dwarf
information.
-G
--stabs
Display the full contents of any sections requested.
Display the contents of the .stab and .stab.index and
.stab.excl sections from an ELF file. This is only
useful on systems (such as Solaris 2.0) in which ".stab"
debugging symbol-table entries are carried in an ELF
section. In most other file formats, debugging symbol-
table entries are interleaved with linkage symbols, and
are visible in the --syms output.
--start-address=address
Start displaying data at the specified address. This
affects the output of the -d, -r and -s options.
--stop-address=address
Stop displaying data at the specified address. This
affects the output of the -d, -r and -s options.
-t
--syms
Print the symbol table entries of the file. This is
similar to the information provided by the nm program,
although the display format is different. The format of
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the output depends upon the format of the file being
dumped, but there are two main types. One looks like
this:
[ 4](sec 3)(fl 0x00)(ty 0)(scl 3) (nx 1) 0x00000000 .bss
[ 6](sec 1)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x00000000 fred
where the number inside the square brackets is the
number of the entry in the symbol table, the sec number
is the section number, the fl value are the symbol's
flag bits, the ty number is the symbol's type, the scl
number is the symbol's storage class and the nx value is
the number of auxilary entries associated with the
symbol. The last two fields are the symbol's value and
its name.
The other common output format, usually seen with ELF
based files, looks like this:
00000000 l d .bss 00000000 .bss
00000000 g .text 00000000 fred
Here the first number is the symbol's value (sometimes
refered to as its address). The next field is actually
a set of characters and spaces indicating the flag bits
that are set on the symbol. These characters are
described below. Next is the section with which the
symbol is associated or *ABS* if the section is absolute
(ie not connected with any section), or *UND* if the
section is referenced in the file being dumped, but not
defined there.
After the section name comes another field, a number,
which for common symbols is the alignment and for other
symbol is the size. Finally the symbol's name is
displayed.
The flag characters are divided into 7 groups as
follows:
"l"
"g"
"u"
"!" The symbol is a local (l), global (g), unique global
(u), neither global nor local (a space) or both
global and local (!). A symbol can be neither local
or global for a variety of reasons, e.g., because it
is used for debugging, but it is probably an
indication of a bug if it is ever both local and
global. Unique global symbols are a GNU extension
to the standard set of ELF symbol bindings. For
such a symbol the dynamic linker will make sure that
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in the entire process there is just one symbol with
this name and type in use.
"w" The symbol is weak (w) or strong (a space).
"C" The symbol denotes a constructor (C) or an ordinary
symbol (a space).
"W" The symbol is a warning (W) or a normal symbol (a
space). A warning symbol's name is a message to be
displayed if the symbol following the warning symbol
is ever referenced.
"I"
"i" The symbol is an indirect reference to another
symbol (I), a function to be evaluated during reloc
processing (i) or a normal symbol (a space).
"d"
"D" The symbol is a debugging symbol (d) or a dynamic
symbol (D) or a normal symbol (a space).
"F"
"f"
"O" The symbol is the name of a function (F) or a file
(f) or an object (O) or just a normal symbol (a
space).
-T
--dynamic-syms
Print the dynamic symbol table entries of the file.
This is only meaningful for dynamic objects, such as
certain types of shared libraries. This is similar to
the information provided by the nm program when given
the -D (--dynamic) option.
--special-syms
When displaying symbols include those which the target
considers to be special in some way and which would not
normally be of interest to the user.
-V
--version
Print the version number of objdump and exit.
-x
--all-headers
Display all available header information, including the
symbol table and relocation entries. Using -x is
equivalent to specifying all of -a -f -h -p -r -t.
-w
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--wide
Format some lines for output devices that have more than
80 columns. Also do not truncate symbol names when they
are displayed.
-z
--disassemble-zeroes
Normally the disassembly output will skip blocks of
zeroes. This option directs the disassembler to
disassemble those blocks, just like any other data.
@file
Read command-line options from file. The options read
are inserted in place of the original @file option. If
file does not exist, or cannot be read, then the option
will be treated literally, and not removed.
Options in file are separated by whitespace. A
whitespace character may be included in an option by
surrounding the entire option in either single or double
quotes. Any character (including a backslash) may be
included by prefixing the character to be included with
a backslash. The file may itself contain additional
@file options; any such options will be processed
recursively.
ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:
+---------------+------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------------+
|Availability | developer/gnu-binutils |
+---------------+------------------------+
|Stability | Uncommitted |
+---------------+------------------------+
SEE ALSO
nm(1), readelf(1), and the Info entries for binutils.
COPYRIGHT
Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation
License, Version 1.3 or any later version published by the
Free Software Foundation; with no Invariant Sections, with
no Front-Cover Texts, and with no Back-Cover Texts. A copy
of the license is included in the section entitled "GNU Free
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Documentation License".
NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://ftp.gnu.org/gnu/binutils/binutils-2.23.1.tar.bz2
Further information about this software can be found on the
open source community website at
http://www.gnu.org/software/binutils/.
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