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objdump

objdump [ -a | --archive-headers ]
[ -b bfdname | --target=bfdname ] [ --debugging ]
[ -d | --disassemble ] [ -D | --disassemble-all ]
[ -f | --file-headers ]
[ -h | --section-headers | --headers ]
[ -i | --info ]
[ -j section | --section=section ]
[ -l | --line-numbers ] [ -S | --source ]
[ -m machine | --architecture=machine ]
[ -r | --reloc ] [ -R | --dynamic-reloc ]
[ -s | --full-contents ] [ --stabs ]
[ -t | --syms ] [ -T | --dynamic-syms ]
[ -x | --all-headers ]
[ -w | --wide ] [ --start-address=address ]
[ --stop-address=address ]
[ --show-raw-insn ]
[ --version ]
[ --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 besides ‘-l’ 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.

-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.

objdump -b oasys -m vax -h fu.o

The previous example 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. See Target Selection for more information.

--debugging
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.

-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.

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

-h
--section-header
--header
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.

--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 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 shown. Only useful with ‘-d’ or ‘-D’.

-m machine
--architecture=machine
Specify that the object files objfile are for architecture machine. You can list available architectures using the ‘-i’ option.

-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.

-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. Not all targets handle this correctly yet.

--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. For more information on stabs symbols, see the directives, .stabd, .stabn, .stabs in “Assembler Directives” in Using AS.

--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.

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

-x
--all-header
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’.

-w
--wide
Format some lines for output devices having more than 80 columns.