objdump − display information from object files.

objdump [−a−−archive−headers]
        [−b bfdname−−target=bfdname]
        [−C−−demangle[=style] ]
        [−EB−EL−−endian={big ⎪ little }]
        [−j section−−section=section]
        [−m machine−−architecture=machine]
        [−M options−−disassembler−options=options]

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,−f,−g,−G,−h,−H,−p,−r,−R,−S,−t,−T,−V,−x must be



    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

    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

    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.


    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


    Display debugging information.  This attempts to parse
    debugging information stored in the file and print it
    out using a C like syntax.  Only certain types of
    debugging information have been implemented.



    Display the assembler mnemonics for the machine
    instructions from objfile.  This option only
    disassembles those sections which are expected to
    contain instructions.


    Like −d, but disassemble the contents of all sections,
    not just those expected to contain instructions.

    When disassembling, print the complete address on each
    line.  This is the older disassembly format.

    Normally the disassembly output will skip blocks of
    zeroes.  This option directs the disassembler to
    disassemble those blocks, just like any other data.



    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.


    Display summary information from the overall header of
    each of the objfile files.

    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.



    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.

    Print a summary of the options to objdump and exit.


    Display a list showing all architectures and object
    formats available for specification with −b or −m.

−j name

    Display information only for section name.


    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

    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.

−M options

    Pass target specific information to the disassembler.
    Only supported on some targets.

    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‐name‐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 name 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
    select disassembly for the given architecture.  intel
    and att select between intel syntax mode and AT&T syntax
    mode.  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 dissassembler to print a
    mnemonic suffix even when the suffix could be inferred
    by the operands.

    For PPC, booke, booke32 and booke64 select disassembly
    of BookE instructions.  32 and 64 select PowerPC and
    PowerPC64 disassembly, respectively.


    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.


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


    Print the dynamic relocation entries of the file.  This
    is only meaningful for dynamic objects, such as certain
    types of shared libraries.



    Display the full contents of any sections requested.


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

    When disassembling instructions, print the instruction
    in hex as well as in symbolic form.  This is the default
    except when −−prefix−addresses is used.

    When disassembling instructions, do not print the
    instruction bytes.  This is the default when
    −−prefix−addresses is used.


    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 displaying data at the specified address.  This
    affects the output of the −d, −r and −s options.

    Stop displaying data at the specified address.  This
    affects the output of the −d, −r and −s options.


    Print the symbol table entries of the file.  This is
    similar to the information provided by the nm program.


    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.

    Print the version number of objdump and exit.


    Display all available header information, including the
    symbol table and relocation entries.  Using −x is
    equivalent to specifying all of −a −f −h −r −t.


    Format some lines for output devices that have more than
    80 columns.  Also do not truncate symbol names when they
    are displayed.

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

Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
2001, 2002 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 1.1 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".