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]
               [-D--disassemble-all]
               [-z--disassemble-zeroes]
               [-EB-EL--endian={big │ little }]
               [-f--file-headers]
               [--file-start-context]
               [-g--debugging]
               [-e--debugging-tags]
               [-h--section-headers--headers]
               [-i--info]
               [-j section--section=section]
               [-l--line-numbers]
               [-S--source]
               [-m machine--architecture=machine]
               [-M options--disassembler-options=options]
               [-p--private-headers]
               [-r--reloc]
               [-R--dynamic-reloc]
               [-s--full-contents]
               [-G--stabs]
               [-t--syms]
               [-T--dynamic-syms]
               [-x--all-headers]
               [-w--wide]
               [--start-address=address]
               [--stop-address=address]
               [--prefix-addresses]
               [--[no-]show-raw-insn]
               [--adjust-vma=offset]
               [--special-syms]
               [-V--version]
               [-H--help]
               objfile...


DESCRIPTION

       objdump  displays  information  about  one  or  more object files.  The
       options control what particular information to display.  This  informa-
       tion 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,-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 corre-
           spond 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  bfd-
           name.   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 com-
           piler.

       -g
       --debugging
           Display debugging information.  This attempts  to  parse  debugging
           information stored in the file and print it out using a C like syn-
           tax.  Only certain types of debugging information have been  imple-
           mented.  Some other types are supported by readelf -w.

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

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

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

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

       -EB
       -EL
       --endian={biglittle}
           Specify the endianness of the object files.  This only affects dis-
           assembly.   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.

       --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 exam-
           ple by using the -Ttext, -Tdata, or -Tbss options to ld.   However,
           some  object file formats, such as a.out, do not store the starting
           address of the file segments.  In  those  situations,  although  ld
           relocates the sections correctly, using objdump -h to list the file
           section headers cannot show the  correct  addresses.   Instead,  it
           shows the usual addresses, which are implicit for the target.

       -H
       --help
           Print a summary of the options to objdump and exit.

       -i
       --info
           Display  a list showing all architectures and object formats avail-
           able for specification with -b or -m.

       -j name
       --section=name
           Display information only for section name.

       -l
       --line-numbers
           Label the display (using debugging information) with  the  filename
           and  source line numbers corresponding to the object code or relocs
           shown.  Only useful with -d, -D, or -r.

       -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.

       -M options
       --disassembler-options=options
           Pass  target  specific  information to the disassembler.  Only sup-
           ported on some targets.  If it is necessary to  specify  more  than
           one disassembler option then multiple -M options can be used or can
           be placed together into a comma separated list.

           If the target is an ARM architecture then this switch can  be  used
           to  select  which  register  name  set is used during disassembler.
           Specifying -M reg-name-std (the default) will select  the  register
           names as used in ARM’s instruction set documentation, but with reg-
           ister 13 called ’sp’, register  14  called  ’lr’  and  register  15
           called ’pc’.  Specifying -M reg-names-apcs will select the name set
           used by the ARM Procedure Call Standard, whilst specifying -M  reg-
           names-raw will just use r followed by the register number.

           There  are  also  two  variants  on the APCS register naming scheme
           enabled by -M reg-names-atpcs and -M reg-names-special-atpcs  which
           use  the  ARM/Thumb  Procedure  Call  Standard  naming conventions.
           (Either with the normal register  names  or  the  special  register
           names).

           This  option  can  also  be used for ARM architectures to force the
           disassembler to interpret all instructions as Thumb instructions by
           using  the  switch --disassembler-options=force-thumb.  This can be
           useful when attempting to disassemble thumb code produced by  other
           compilers.

           For  the  x86,  some  of  the options duplicate functions of the -m
           switch, but allow finer grained control.  Multiple selections  from
           the  following  may  be  specified  as  a  comma  separated string.
           x86-64, i386 and i8086 select disassembly for the  given  architec-
           ture.  intel and att select between intel syntax mode and AT&T syn-
           tax mode.  addr32, addr16, data32 and data16  specify  the  default
           address size and operand size.  These four options will be overrid-
           den if x86-64, i386 or i8086 appear later  in  the  option  string.
           Lastly,  suffix,  when  in AT&T mode, instructs the disassembler to
           print a mnemonic suffix even when the suffix could be  inferred  by
           the operands.

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

           For  MIPS,  this  option controls the printing of register names in
           disassembled instructions.  Multiple selections from the  following
           may  be  specified as a comma separated string, and invalid options
           are ignored:

           "gpr-names=ABI"
               Print GPR (general-purpose register) names as  appropriate  for
               the  specified ABI.  By default, GPR names are selected accord-
               ing 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.

       -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.

       -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.

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

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

       --show-raw-insn
           When  disassembling  instructions,  print the instruction in hex as
           well as in symbolic form.  This is the default except  when  --pre-
           fix-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.

       -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.

       -T
       --dynamic-syms
           Print  the  dynamic symbol table entries of the file.  This is only
           meaningful for dynamic objects, such as  certain  types  of  shared
           libraries.   This  is similar to the information provided by the nm
           program when given the -D (--dynamic) option.

       --special-syms
           When displaying symbols include those which the target considers to
           be  special in some way and which would not normally be of interest
           to the user.

       -V
       --version
           Print the version number of objdump and exit.

       -x
       --all-headers
           Display all available header information, including the symbol  ta-
           ble  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 dis-
           played.

       -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.


SEE ALSO

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


COPYRIGHT

       Copyright (c) 1991, 1992, 1993, 1994, 1995,  1996,  1997,  1998,  1999,
       2000, 2001, 2002, 2003, 2004 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’’.



binutils-2.15.94.0.2.2            2005-06-29                        OBJDUMP(1)

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