OBJDUMP(1)                  GNU Development Tools                 OBJDUMP(1)

NAME         top

       objdump - display information from object files.

SYNOPSIS         top

       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]
               [-P options|--private=options]

DESCRIPTION         top

       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

OPTIONS         top

       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

           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.

           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 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.

           Like -g, but the information is generated in a format compatible
           with ctags tool.

           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.

           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.

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

           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

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

           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.

           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

           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.

           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.

           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
           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
           souble precision FP instructions.

           cpu=... allows 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=...

           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.

               Select disassembly for the given architecture.

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

               Select between AMD64 ISA and Intel64 ISA.

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

               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.

               When in AT&T mode, instructs the disassembler to print a
               mnemonic suffix even when the suffix could be inferred by the

           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,
           e200z4, e300, e500, e500mc, e500mc64, e500x2, e5500, e6500, efs,
           power4, power5, power6, power7, power8, power9, ppc, ppc32,
           ppc64, ppc64bridge, ppcps, pwr, pwr2, pwr4, pwr5, pwr5x, pwr6,
           pwr7, pwr8, pwr9, pwrx, titan, and vle.  32 and 64 modify the
           default or a prior CPU selection, disabling and enabling 64-bit
           insns respectively.  In addition, altivec, any, htm, vsx, and spe
           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:

               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.

               Disassemble MSA instructions.

               Disassemble the virtualization ASE instructions.

               Disassemble the eXtended Physical Address (XPA) ASE

               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.

               Print FPR (floating-point register) names as appropriate for
               the specified ABI.  By default, FPR numbers are printed
               rather than names.

               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.

               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

               Print GPR and FPR names as appropriate for the selected ABI.

               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.

           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
           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:


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

           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.  As for -r, if used with -d or -D, the relocations are
           printed interspersed with the disassembly.

           Display the full contents of any sections requested.  By default
           all non-empty sections are displayed.

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

           Specify prefix to add to the absolute paths when used with -S.

           Indicate how many initial directory names to strip off the
           hardwired absolute paths. It has no effect without

           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 width bytes on a single line when disassembling

           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

           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 affected by
           the options --dwarf-depth, the --dwarf-start and the

           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.

           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.

           Enable additional checks for consistency of Dwarf information.

           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, 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 auxilary entries associated with
           the symbol.  The last two fields are the symbol's value and its

           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

           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:

           "!" 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

           "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" 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" The symbol is a debugging symbol (d) or a dynamic symbol (D)
               or a normal symbol (a space).

           "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).

           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.

           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.

           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 -p -r -t.

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

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

           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         top

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

COPYRIGHT         top

       Copyright (c) 1991-2017 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".

COLOPHON         top

       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 ⟨⟩.  If you have a
       bug report for this manual page, see 
       ⟨⟩.  This
       page was obtained from the tarball binutils-2.29.tar.gz fetched from
       ⟨⟩ on 2017-09-15.  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

binutils-2.29                    2017-07-24                       OBJDUMP(1)

Pages that refer to this page: dl_iterate_phdr(3)end(3)deb-symbols(5)elf(5)tc-bpf(8)