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NAME    [Toc]    [Back]

       objdump - display information from object files.

SYNOPSIS    [Toc]    [Back]

       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]

DESCRIPTION    [Toc]    [Back]

       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    [Toc]    [Back]

       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 given.

	   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 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.

	   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.

	   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  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

	   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

	   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,

	   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

	   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	--pre-
	   fix-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.

SEE ALSO    [Toc]    [Back]

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

COPYRIGHT    [Toc]    [Back]

       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".

3rd Berkeley Distribution	  2002-04-18			    OBJDUMP(1)
[ Back ]
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