OBJDUMP 1 2005-04-20 binutils-2.15.97 GNU Development Tools

NAME

objdump - display information from object files.

SYNOPSIS

objdump [--aa|----aarrcchhiivvee--hheeaaddeerrss] [--bb _b_f_d_n_a_m_e|----ttaarrggeett==_b_f_d_n_a_m_e] [--CC|----ddeemmaannggllee[=_s_t_y_l_e] ] [--dd|----ddiissaasssseemmbbllee] [--DD|----ddiissaasssseemmbbllee--aallll] [--zz|----ddiissaasssseemmbbllee--zzeerrooeess] [--EEBB|--EELL|----eennddiiaann=={big | little }] [--ff|----ffiillee--hheeaaddeerrss] [----ffiillee--ssttaarrtt--ccoonntteexxtt] [--gg|----ddeebbuuggggiinngg] [--ee|----ddeebbuuggggiinngg--ttaaggss] [--hh|----sseeccttiioonn--hheeaaddeerrss|----hheeaaddeerrss] [--ii|----iinnffoo] [--jj _s_e_c_t_i_o_n|----sseeccttiioonn==_s_e_c_t_i_o_n] [--ll|----lliinnee--nnuummbbeerrss] [--SS|----ssoouurrccee] [--mm _m_a_c_h_i_n_e|----aarrcchhiitteeccttuurree==_m_a_c_h_i_n_e] [--MM _o_p_t_i_o_n_s|----ddiissaasssseemmbblleerr--ooppttiioonnss==_o_p_t_i_o_n_s] [--pp|----pprriivvaattee--hheeaaddeerrss] [--rr|----rreelloocc] [--RR|----ddyynnaammiicc--rreelloocc] [--ss|----ffuullll--ccoonntteennttss] [--GG|----ssttaabbss] [--tt|----ssyymmss] [--TT|----ddyynnaammiicc--ssyymmss] [--xx|----aallll--hheeaaddeerrss] [--ww|----wwiiddee] [----ssttaarrtt--aaddddrreessss==_a_d_d_r_e_s_s] [----ssttoopp--aaddddrreessss==_a_d_d_r_e_s_s] [----pprreeffiixx--aaddddrreesssseess] [----[[nnoo--]]sshhooww--rraaww--iinnssnn] [----aaddjjuusstt--vvmmaa==_o_f_f_s_e_t] [----ssppeecciiaall--ssyymmss] [--VV|----vveerrssiioonn] [--HH|----hheellpp] _o_b_j_f_i_l_e...

DESCRIPTION

oobbjjdduummpp 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.

_o_b_j_f_i_l_e... are the object files to be examined. When you specify archives, oobbjjdduummpp 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 --aa,,--dd,,--DD,,--ee,,--ff,,--gg,,--GG,,--hh,,--HH,,--pp,,--rr,,--RR,,--ss,,--SS,,--tt,,--TT,,--VV,,--xx must be given.
--aa
----aarrcchhiivvee--hheeaaddeerr If any of the _o_b_j_f_i_l_e files are archives, display the archive
header information (in a format similar to llss --ll). Besides the information you could list with aarr ttvv, oobbjjdduummpp --aa shows the object file format of each archive member.
----aaddjjuusstt--vvmmaa==_o_f_f_s_e_t When dumping information, first add _o_f_f_s_e_t 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.
--bb _b_f_d_n_a_m_e
----ttaarrggeett==_b_f_d_n_a_m_e Specify that the object-code format for the object files is
_b_f_d_n_a_m_e. This option may not be necessary; _o_b_j_d_u_m_p can automatically recognize many formats.

For example,


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


displays summary information from the section headers (--hh) of _f_u_._o, which is explicitly identified (--mm) as a VAX object file in the format produced by Oasys compilers. You can list the formats available with the --ii option.
--CC
----ddeemmaannggllee[[==_s_t_y_l_e]] Decode (_d_e_m_a_n_g_l_e) 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.
--gg
----ddeebbuuggggiinngg 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. Some other types are supported by rreeaaddeellff --ww.
--ee
----ddeebbuuggggiinngg--ttaaggss Like --gg, but the information is generated in a format compatible
with ctags tool.
--dd
----ddiissaasssseemmbbllee Display the assembler mnemonics for the machine instructions from
_o_b_j_f_i_l_e. This option only disassembles those sections which are expected to contain instructions.
--DD
----ddiissaasssseemmbbllee--aallll Like --dd, but disassemble the contents of all sections, not just
those expected to contain instructions.
----pprreeffiixx--aaddddrreesssseess When disassembling, print the complete address on each line. This is
the older disassembly format.
--EEBB
--EELL
----eennddiiaann=={{bbiigg||lliittttllee}} 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.
--ff
----ffiillee--hheeaaddeerrss Display summary information from the overall header of
each of the _o_b_j_f_i_l_e files.
----ffiillee--ssttaarrtt--ccoonntteexxtt Specify that when displaying interlisted source code/disassembly
(assumes --SS) from a file that has not yet been displayed, extend the context to the start of the file.
--hh
----sseeccttiioonn--hheeaaddeerrss
----hheeaaddeerrss Display summary information from the section headers of the
object file.

File segments may be relocated to nonstandard addresses, for example by using the --TTtteexxtt, --TTddaattaa, or --TTbbssss options to lldd. However, some object file formats, such as a.out, do not store the starting address of the file segments. In those situations, although lldd relocates the sections correctly, using oobbjjdduummpp --hh to list the file section headers cannot show the correct addresses. Instead, it shows the usual addresses, which are implicit for the target.
--HH
----hheellpp Print a summary of the options to oobbjjdduummpp and exit.
--ii
----iinnffoo Display a list showing all architectures and object formats available
for specification with --bb or --mm.
--jj _n_a_m_e
----sseeccttiioonn==_n_a_m_e Display information only for section _n_a_m_e.
--ll
----lliinnee--nnuummbbeerrss Label the display (using debugging information) with the filename and
source line numbers corresponding to the object code or relocs shown. Only useful with --dd, --DD, or --rr.
--mm _m_a_c_h_i_n_e
----aarrcchhiitteeccttuurree==_m_a_c_h_i_n_e 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 --ii option.
--MM _o_p_t_i_o_n_s
----ddiissaasssseemmbblleerr--ooppttiioonnss==_o_p_t_i_o_n_s 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 --MM 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 --MM rreegg--nnaammee--ssttdd (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 --MM rreegg--nnaammeess--aappccss will select the name set used by the ARM Procedure Call Standard, whilst specifying --MM rreegg--nnaammeess--rraaww will just use rr followed by the register number.

There are also two variants on the APCS register naming scheme enabled by --MM rreegg--nnaammeess--aattppccss and --MM rreegg--nnaammeess--ssppeecciiaall--aattppccss 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 ----ddiissaasssseemmbblleerr--ooppttiioonnss==ffoorrccee--tthhuummbb. 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 --mm switch, but allow finer grained control. Multiple selections from the following may be specified as a comma separated string. xx8866--6644, ii338866 and ii88008866 select disassembly for the given architecture. iinntteell and aatttt select between intel syntax mode and AT&T syntax mode. aaddddrr3322, aaddddrr1166, ddaattaa3322 and ddaattaa1166 specify the default address size and operand size. These four options will be overridden if xx8866--6644, ii338866 or ii88008866 appear later in the option string. Lastly, ssuuffffiixx, 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, bbooookkee, bbooookkee3322 and bbooookkee6644 select disassembly of BookE instructions. 3322 and 6644 select PowerPC and PowerPC64 disassembly, respectively.

For MIPS, this option controls the printing of instruction mneumonic 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:
"no-aliases" Print the 'raw' instruction mneumonic instead of some pseudo
instruction mneumonic. I.E. print 'daddu' or 'or' instead of 'move', 'sll' instead of 'nop', etc.
"gpr-names=ABI" 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.
"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 _A_R_C_H. 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 _A_R_C_H. 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, _A_B_I or _A_R_C_H may be specified as nnuummeerriicc to have numbers printed rather than names, for the selected types of registers. You can list the available values of _A_B_I and _A_R_C_H using the ----hheellpp option.
--pp
----pprriivvaattee--hheeaaddeerrss 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.
--rr
----rreelloocc Print the relocation entries of the file. If used with --dd or
--DD, the relocations are printed interspersed with the disassembly.
--RR
----ddyynnaammiicc--rreelloocc Print the dynamic relocation entries of the file. This is only
meaningful for dynamic objects, such as certain types of shared libraries.
--ss
----ffuullll--ccoonntteennttss Display the full contents of any sections requested. By default all
non-empty sections are displayed.
--SS
----ssoouurrccee Display source code intermixed with disassembly, if possible. Implies
--dd.
----sshhooww--rraaww--iinnssnn When disassembling instructions, print the instruction in hex as well as
in symbolic form. This is the default except when ----pprreeffiixx--aaddddrreesssseess is used.
----nnoo--sshhooww--rraaww--iinnssnn When disassembling instructions, do not print the instruction bytes.
This is the default when ----pprreeffiixx--aaddddrreesssseess is used.
--GG
----ssttaabbss 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 ----ssyymmss output.
----ssttaarrtt--aaddddrreessss==_a_d_d_r_e_s_s Start displaying data at the specified address. This affects the output
of the --dd, --rr and --ss options.
----ssttoopp--aaddddrreessss==_a_d_d_r_e_s_s Stop displaying data at the specified address. This affects the output
of the --dd, --rr and --ss options.
--tt
----ssyymmss Print the symbol table entries of the file.
This is similar to the information provided by the nnmm program.
--TT
----ddyynnaammiicc--ssyymmss 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 nnmm program when given the --DD (----ddyynnaammiicc) option.
----ssppeecciiaall--ssyymmss 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.
--VV
----vveerrssiioonn Print the version number of oobbjjdduummpp and exit.
--xx
----aallll--hheeaaddeerrss Display all available header information, including the symbol table and
relocation entries. Using --xx is equivalent to specifying all of --aa --ff --hh --pp --rr --tt.
--ww
----wwiiddee Format some lines for output devices that have more than 80 columns.
Also do not truncate symbol names when they are displayed.
--zz
----ddiissaasssseemmbbllee--zzeerrooeess 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

_n_m(1), _r_e_a_d_e_l_f(1), and the Info entries for _b_i_n_u_t_i_l_s. 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''.