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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COPYRIGHT | COLOPHON |
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OBJDUMP(1) GNU Development Tools OBJDUMP(1)
objdump - display information from object files
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...
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.
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, then display the assembler
mnemonics starting at 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 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, ppc, ppc32, ppc64,
ppc64bridge, ppcps, pwr, pwr2, pwr4, pwr5, pwr5x, pwr6, pwr7,
pwr8, pwr9, pwr10, 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 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.
-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=extened|extended-color|extened-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.
--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.
nm(1), readelf(1), and the Info entries for binutils.
Copyright (c) 1991-2024 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 Documentation
License".
This page is part of the binutils (a collection of tools for
working with executable binaries) project. Information about the
project can be found at ⟨http://www.gnu.org/software/binutils/⟩.
If you have a bug report for this manual page, see
⟨http://sourceware.org/bugzilla/enter_bug.cgi?product=binutils⟩.
This page was obtained from the tarball binutils-2.42.tar.gz
fetched from ⟨https://ftp.gnu.org/gnu/binutils/⟩ on 2024-06-14.
If you discover any rendering problems in this HTML version of
the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to
the information in this COLOPHON (which is not part of the
original manual page), send a mail to man-pages@man7.org
binutils-2.42 2024-06-14 OBJDUMP(1)
Pages that refer to this page: ld(1), nm(1), objcopy(1), readelf(1), size(1), strings(1), dl_iterate_phdr(3), end(3), deb-symbols(5), elf(5), tc-bpf(8)
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