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Manual: x86_64-linux-gnu-objdump

OBJDUMP(1) 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[=symbol]]
[-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]
[--source-comment[=text]]
[-m machine|--architecture=machine]
[-M options|--disassembler-options=options]
[-p|--private-headers]
[-P options|--private=options]
[-r|--reloc]
[-R|--dynamic-reloc]
[-s|--full-contents]
[-Z|--decompress]
[-W[lLiaprmfFsoORtUuTgAck]|
--dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
[-WK|--dwarf=follow-links]
[-WN|--dwarf=no-follow-links]
[-wD|--dwarf=use-debuginfod]
[-wE|--dwarf=do-not-use-debuginfod]
[-L|--process-links]
[--ctf=section]
[--sframe=section]
[-G|--stabs]
[-t|--syms]
[-T|--dynamic-syms]
[-x|--all-headers]
[-w|--wide]
[--start-address=address]
[--stop-address=address]
[--no-addresses]
[--prefix-addresses]
[--[no-]show-raw-insn]
[--adjust-vma=offset]
[--show-all-symbols]
[--dwarf-depth=n]
[--dwarf-start=n]
[--ctf-parent=section]
[--no-recurse-limit|--recurse-limit]
[--special-syms]
[--prefix=prefix]
[--prefix-strip=level]
[--insn-width=width]
[--visualize-jumps[=color|=extended-color|=off]
[--disassembler-color=[off|terminal|on|extended]
[-U method] [--unicode=method]
[-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 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 styles. The optional demangling style argument can be used to choose an
appropriate demangling style for your compiler.

--recurse-limit
--no-recurse-limit
--recursion-limit
--no-recursion-limit
Enables or disables a limit on the amount of recursion performed whilst demangling strings.
Since the name mangling formats allow for an infinite level of recursion it is possible to create
strings whose decoding will exhaust the amount of stack space available on the host machine,
triggering a memory fault. The limit tries to prevent this from happening by restricting
recursion to 2048 levels of nesting.

The default is for this limit to be enabled, but disabling it may be necessary in order to
demangle truly complicated names. Note however that if the recursion limit is disabled then
stack exhaustion is possible and any bug reports about such an event will be rejected.

-g
--debugging
Display debugging information. This attempts to parse STABS debugging format information stored
in the file and print it out using a C like syntax. If no STABS debugging was 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
--disassemble=symbol
Display the assembler mnemonics for the machine instructions from the input file. This option
only disassembles those sections which are expected to contain instructions. If the optional
symbol argument is given (perhaps multiple times), then display the assembler mnemonics starting
at (all the) symbol. If symbol is a function name then disassembly will stop at the end of the
function, otherwise it will stop when the next symbol is encountered. If there are no matches
for any symbol then nothing will be displayed.

Note if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info
files will be read in and used when disassembling.

-D
--disassemble-all
Like -d, but disassemble the contents of all non-empty non-bss sections, not just those expected
to contain instructions. -j may be used to select specific sections.

This option also has a subtle effect on the disassembly of instructions in code sections. When
option -d is in effect objdump will assume that any symbols present in a code section occur on
the boundary between instructions and it will refuse to disassemble across such a boundary. When
option -D is in effect however this assumption is supressed. This means that it is possible for
the output of -d and -D to differ if, for example, data is stored in code sections.

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.

Note if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info
files will be read in and used when disassembling.

--no-addresses
When disassembling, don't print addresses on each line or for symbols and relocation offsets. In
combination with --no-show-raw-insn this may be useful for comparing compiler output.

--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.

-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.

Note, in some cases it is possible for a section to have both the READONLY and the NOREAD
attributes set. In such cases the NOREAD attribute takes precedence, but objdump will report
both since the exact setting of the flag bits might be important.

-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 for section name. This option may be specified multiple times.

-L
--process-links
Display the contents of non-debug sections found in separate debuginfo files that are linked to
the main file. This option automatically implies the -WK option, and only sections requested by
other command line options will be displayed.

-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.

-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.

For most architectures it is possible to supply an architecture name and a machine name,
separated by a colon. For example foo:bar would refer to the bar machine type in the foo
architecture. This can be helpful if objdump has been configured to support multiple
architectures.

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.

For ARC, dsp controls the printing of DSP instructions, spfp selects the printing of FPX single
precision FP instructions, dpfp selects the printing of FPX double precision FP instructions,
quarkse_em selects the printing of special QuarkSE-EM instructions, fpuda selects the printing of
double precision assist instructions, fpus selects the printing of FPU single precision FP
instructions, while fpud selects the printing of FPU double precision FP instructions.
Additionally, one can choose to have all the immediates printed in hexadecimal using hex. By
default, the short immediates are printed using the decimal representation, while the long
immediate values are printed as hexadecimal.

cpu=... allows one to enforce a particular ISA when disassembling instructions, overriding the -m
value or whatever is in the ELF file. This might be useful to select ARC EM or HS ISA, because
architecture is same for those and disassembler relies on private ELF header data to decide if
code is for EM or HS. This option might be specified multiple times - only the latest value will
be used. Valid values are same as for the assembler -mcpu=... option.

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 AArch64 targets this switch can be used to set whether instructions are disassembled as the
most general instruction using the -M no-aliases option or whether instruction notes should be
generated as comments in the disasssembly using -M notes.

For the x86, some of the options duplicate functions of the -m switch, but allow finer grained
control.

"x86-64"
"i386"
"i8086"
Select disassembly for the given architecture.

"intel"
"att"
Select between intel syntax mode and AT&T syntax mode.

"amd64"
"intel64"
Select between AMD64 ISA and Intel64 ISA.

"intel-mnemonic"
"att-mnemonic"
Select between intel mnemonic mode and AT&T mnemonic mode. Note: "intel-mnemonic" implies
"intel" and "att-mnemonic" implies "att".

"addr64"
"addr32"
"addr16"
"data32"
"data16"
Specify the default address size and operand size. These five options will be overridden if
"x86-64", "i386" or "i8086" appear later in the option string.

"suffix"
When in AT&T mode and also for a limited set of instructions when in Intel mode, instructs
the disassembler to print a mnemonic suffix even when the suffix could be inferred by the
operands or, for certain instructions, the execution mode's defaults.

For PowerPC, the -M argument raw selects disasssembly of hardware insns rather than aliases. For
example, you will see "rlwinm" rather than "clrlwi", and "addi" rather than "li". All of the -m
arguments for gas that select a CPU are supported. These are: 403, 405, 440, 464, 476, 601, 603,
604, 620, 7400, 7410, 7450, 7455, 750cl, 821, 850, 860, a2, booke, booke32, cell, com, e200z2,
e200z4, e300, e500, e500mc, e500mc64, e500x2, e5500, e6500, efs, power4, power5, power6, power7,
power8, power9, power10, power11, ppc, ppc32, ppc64, ppc64bridge, ppcps, pwr, pwr2, pwr4, pwr5,
pwr5x, pwr6, pwr7, pwr8, pwr9, pwr10, pwr11, pwrx, titan, vle, and future. 32 and 64 modify the
default or a prior CPU selection, disabling and enabling 64-bit insns respectively. In addition,
altivec, any, lsp, htm, vsx, spe and spe2 add capabilities to a previous or later CPU selection.
any will disassemble any opcode known to binutils, but in cases where an opcode has two different
meanings or different arguments, you may not see the disassembly you expect. If you disassemble
without giving a CPU selection, a default will be chosen from information gleaned by BFD from the
object files headers, but the result again may not be as you expect.

For RISC-V, the following options are supported:

"max"
Disassemble without checking architecture string. This is a best effort mode, so for
overlapping ISA extensions the first match (possibly incorrect in a given context) will be
used to decode the instruction. It's useful, if the ELF file doesn't expose ISA string,
preventing automatic ISA subset deduction, and the default fallback ISA string ("rv64gc")
doesn't cover all instructions in the binary.

"numeric"
Print numeric register names, rather than ABI names (e.g., print "x2" instead of "sp").

"no-aliases"
Disassemble only into canonical instructions. For example, compressed instructions will be
represented as such ("addi sp,sp,-128" will be "c.addi16sp sp,-128").

"priv-spec=SPEC"
Print the CSR according to the chosen privilege spec version (e.g., 1.10, 1.11, 1.12, 1.13).

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.

"msa"
Disassemble MSA instructions.

"virt"
Disassemble the virtualization ASE instructions.

"xpa"
Disassemble the eXtended Physical Address (XPA) ASE instructions.

"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" 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"
"toc"
"ldinfo"

For PE, the available options are:

"header"
"sections"

Not all object formats support this option. In particular the ELF format does not use it.

-r
--reloc
Print the relocation entries of the file. If used with -d or -D, the relocations are printed
interspersed with the disassembly.

-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.

Note: objdump does not support displaying RELR type relocations. These can be displayed by the
readelf program.

-s
--full-contents
Display the full contents of sections, often used in combination with -j to request specific
sections. By default all non-empty non-bss sections are displayed. By default any compressed
section will be displayed in its compressed form. In order to see the contents in a decompressed
form add the -Z option to the command line.

-S
--source
Display source code intermixed with disassembly, if possible. Implies -d.

--show-all-symbols
When disassembling, show all the symbols that match a given address, not just the first one.

--source-comment[=txt]
Like the -S option, but all source code lines are displayed with a prefix of txt. Typically txt
will be a comment string which can be used to distinguish the assembler code from the source
code. If txt is not provided then a default string of "# " (hash followed by a space), will be
used.

--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.

--visualize-jumps[=color|=extended-color|=off]
Visualize jumps that stay inside a function by drawing ASCII art between the start and target
addresses. The optional =color argument adds color to the output using simple terminal colors.
Alternatively the =extended-color argument will add color using 8bit colors, but these might not
work on all terminals.

If it is necessary to disable the visualize-jumps option after it has previously been enabled
then use visualize-jumps=off.

--disassembler-color=off
--disassembler-color=terminal
--disassembler-color=on|color|colour
--disassembler-color=extended|extended-color|extended-colour
Enables or disables the use of colored syntax highlighting in disassembly output. The default
behaviour is determined via a configure time option. Note, not all architectures support colored
syntax highlighting, and depending upon the terminal used, colored output may not actually be
legible.

The on argument adds colors using simple terminal colors.

The terminal argument does the same, but only if the output device is a terminal.

The extended-color argument is similar to the on argument, but it uses 8-bit colors. These may
not work on all terminals.

The off argument disables colored disassembly.

-W[lLiaprmfFsoORtUuTgAckK]
--dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]
Displays the contents of the DWARF debug sections in the file, if any are present. Compressed
debug sections are automatically decompressed (temporarily) before they are displayed. If one or
more of the optional letters or words follows the switch then only those type(s) of data will be
dumped. The letters and words refer to the following information:

"a"
"=abbrev"
Displays the contents of the .debug_abbrev section.

"A"
"=addr"
Displays the contents of the .debug_addr section.

"c"
"=cu_index"
Displays the contents of the .debug_cu_index and/or .debug_tu_index sections.

"f"
"=frames"
Display the raw contents of a .debug_frame section.

"F"
"=frames-interp"
Display the interpreted contents of a .debug_frame section.

"g"
"=gdb_index"
Displays the contents of the .gdb_index and/or .debug_names sections.

"i"
"=info"
Displays the contents of the .debug_info section. Note: the output from this option can also
be restricted by the use of the --dwarf-depth and --dwarf-start options.

"k"
"=links"
Displays the contents of the .gnu_debuglink, .gnu_debugaltlink and .debug_sup sections, if
any of them are present. Also displays any links to separate dwarf object files (dwo), if
they are specified by the DW_AT_GNU_dwo_name or DW_AT_dwo_name attributes in the .debug_info
section.

"K"
"=follow-links"
Display the contents of any selected debug sections that are found in linked, separate debug
info file(s). This can result in multiple versions of the same debug section being displayed
if it exists in more than one file.

In addition, when displaying DWARF attributes, if a form is found that references the
separate debug info file, then the referenced contents will also be displayed.

Note - in some distributions this option is enabled by default. It can be disabled via the N
debug option. The default can be chosen when configuring the binutils via the
--enable-follow-debug-links=yes or --enable-follow-debug-links=no options. If these are not
used then the default is to enable the following of debug links.

Note - if support for the debuginfod protocol was enabled when the binutils were built then
this option will also include an attempt to contact any debuginfod servers mentioned in the
DEBUGINFOD_URLS environment variable. This could take some time to resolve. This behaviour
can be disabled via the =do-not-use-debuginfod debug option.

"N"
"=no-follow-links"
Disables the following of links to separate debug info files.

"D"
"=use-debuginfod"
Enables contacting debuginfod servers if there is a need to follow debug links. This is the
default behaviour.

"E"
"=do-not-use-debuginfod"
Disables contacting debuginfod servers when there is a need to follow debug links.

"l"
"=rawline"
Displays the contents of the .debug_line section in a raw format.

"L"
"=decodedline"
Displays the interpreted contents of the .debug_line section.

"m"
"=macro"
Displays the contents of the .debug_macro and/or .debug_macinfo sections.

"o"
"=loc"
Displays the contents of the .debug_loc and/or .debug_loclists sections.

"O"
"=str-offsets"
Displays the contents of the .debug_str_offsets section.

"p"
"=pubnames"
Displays the contents of the .debug_pubnames and/or .debug_gnu_pubnames sections.

"r"
"=aranges"
Displays the contents of the .debug_aranges section.

"R"
"=Ranges"
Displays the contents of the .debug_ranges and/or .debug_rnglists sections.

"s"
"=str"
Displays the contents of the .debug_str, .debug_line_str and/or .debug_str_offsets sections.

"t"
"=pubtype"
Displays the contents of the .debug_pubtypes and/or .debug_gnu_pubtypes sections.

"T"
"=trace_aranges"
Displays the contents of the .trace_aranges section.

"u"
"=trace_abbrev"
Displays the contents of the .trace_abbrev section.

"U"
"=trace_info"
Displays the contents of the .trace_info section.

Note: displaying the contents of .debug_static_funcs, .debug_static_vars and debug_weaknames
sections is not currently supported.

--dwarf-depth=n
Limit the dump of the ".debug_info" section to n children. This is only useful with
--debug-dump=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 --debug-dump=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.

--ctf[=section]
Display the contents of the specified CTF section. CTF sections themselves contain many
subsections, all of which are displayed in order.

By default, display the name of the section named .ctf, which is the name emitted by ld.

--ctf-parent=member
If the CTF section contains ambiguously-defined types, it will consist of an archive of many CTF
dictionaries, all inheriting from one dictionary containing unambiguous types. This member is by
default named .ctf, like the section containing it, but it is possible to change this name using
the "ctf_link_set_memb_name_changer" function at link time. When looking at CTF archives that
have been created by a linker that uses the name changer to rename the parent archive member,
--ctf-parent can be used to specify the name used for the parent.

--ctf-parent-section=section
This option lets you pick a completely different section for the CTF parent dictionary containing
unambiguous types than for the child dictionaries that contain the ambiguous remainder. The
linker does not emit ELF objects structured like this, but some third-party linkers may. It's
also convenient to inspect CTF written out as multiple raw files to compose them with objcopy,
which can put them in different ELF sections but not in different members of a single CTF dict.

--sframe[=section]
Display the contents of the specified SFrame section.

By default, display the name of the section named .sframe, which is the name emitted by ld.

-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 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
auxiliary 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 referred 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 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.

The output format is similar to that produced by the --syms option, except that an extra field is
inserted before the symbol's name, giving the version information associated with the symbol. If
the version is the default version to be used when resolving unversioned references to the symbol
then it's displayed as is, otherwise it's put into parentheses.

--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.

-U [d|i|l|e|x|h]
--unicode=[default|invalid|locale|escape|hex|highlight]
Controls the display of UTF-8 encoded multibyte characters in strings. The default
(--unicode=default) is to give them no special treatment. The --unicode=locale option displays
the sequence in the current locale, which may or may not support them. The options --unicode=hex
and --unicode=invalid display them as hex byte sequences enclosed by either angle brackets or
curly braces.

The --unicode=escape option displays them as escape sequences (\uxxxx) and the
--unicode=highlight option displays them as escape sequences highlighted in red (if supported by
the output device). The colouring is intended to draw attention to the presence of unicode
sequences where they might not be expected.

-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
--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.

-Z
--decompress
The -Z option is meant to be used in conunction with the -s option. It instructs objdump to
decompress any compressed sections before displaying their contents.

@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.

SEE ALSO
nm(1), readelf(1), and the Info entries for binutils.

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 Documentation License".

binutils-2.46 2026-03-15 OBJDUMP(1)

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Manual: x86_64-linux-gnu-objdump

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