OBJDUMP(1)

πŸ“¦
version 2.46.1 Β· 5 versions
, in fedora 44

πŸ’– OBJDUMP(1) β€” GNU Development Tools πŸ’–

okay bestie, sit down, hydrate, because we are about to read object files together and it's gonna be a whole ✨journey✨. this is the objdump page from the GNU Development Tools manual, and yes she is long, so we're doing her in parts. part 1, let's go 🫢


✨ NAME ✨

objdump β€” display information from object files


✨ SYNOPSIS ✨

objdump [-a|--archive-headers]
        [-b bfdname|--target=bfdname]
        [-C|--demangle[=style] ]
        [-d|--disassemble[=symbol]]
        [-D|--disassemble-all]
        [-z|--disassemble-zeroes]
        [-EB|-EL|--endian={big | little }]
        [-f|--file-headers]
        [-F|--file-offsets]
        [--file-start-context]
        [-g|--debugging]
        [-e|--debugging-tags]
        [-h|--section-headers|--headers]
        [-i|--info]
        [-j section|--section=section]
        [-l|--line-numbers]
        [-S|--source]
        [--source-comment[=text]]
        [-m machine|--architecture=machine]
        [-M options|--disassembler-options=options]
        [-p|--private-headers]
        [-P options|--private=options]
        [-r|--reloc]
        [-R|--dynamic-reloc]
        [-s|--full-contents]
        [-Z|--decompress]
        [-W[lLiaprmfFsoORtUuTgAck]|
         --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
        [-WK|--dwarf=follow-links]
        [-WN|--dwarf=no-follow-links]
        [-wD|--dwarf=use-debuginfod]
        [-wE|--dwarf=do-not-use-debuginfod]
        [-L|--process-links]
        [--ctf=section]
        [--sframe=section]
        [-G|--stabs]
        [-t|--syms]
        [-T|--dynamic-syms]
        [-x|--all-headers]
        [-w|--wide]
        [--start-address=address]
        [--stop-address=address]
        [--no-addresses]
        [--prefix-addresses]
        [--[no-]show-raw-insn]
        [--adjust-vma=offset]
        [--show-all-symbols]
        [--dwarf-depth=n]
        [--dwarf-start=n]
        [--ctf-parent=section]
        [--no-recurse-limit|--recurse-limit]
        [--special-syms]
        [--prefix=prefix]
        [--prefix-strip=level]
        [--insn-width=width]
        [--visualize-jumps[=color|=extended-color|=off]
        [--disassembler-color=[off|terminal|on|extended]
        [-U method] [--unicode=method]
        [-V|--version]
        [-H|--help]
        objfile...

🌸 DESCRIPTION 🌸

objdump spills the tea β˜• about one or more object files. the options are what control which particular info she shows you. ngl this info is mostly for the programmers who are out here working on compilation tools β€” not the ones who just want their program to compile and work, iykyk.

objfile... are the object files getting examined. and when you hand her archives? she shows you info on each and every member object file inside. every single one. she does not skip πŸ’…


πŸŽ€ OPTIONS πŸŽ€

the long and short forms of options, shown here as alternatives, are equivalent. fr fr, pick whichever.

⚠️ okay important: at least one option from this list has to be given β€” -a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x. like, she needs something to do, bestie 😭
  • -a, --archive-header β€” if any of the objfile files are archives, she shows you the archive header info (in a format similar to ls -l). and on top of the stuff you could already list with ar tv, objdump -a also shows the object file format of each archive member. extra ✨
  • --adjust-vma=offset β€” when dumping info, first add offset to all the section addresses. this is useful if the section addresses don't correspond to the symbol table, which can happen when you're putting sections at particular addresses while using a format that can't represent section addresses, like a.out.
  • -b bfdname, --target=bfdname β€” specify that the object-code format for the object files is bfdname. this option may not even be necessary β€” objdump can automatically recognize many formats, she's smart like that.

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] β€” 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, so the optional demangling style argument can be used to choose an appropriate demangling style for your compiler.
  • --recurse-limit, --no-recurse-limit, --recursion-limit, --no-recursion-limit β€” enables or disables a limit on the amount of recursion performed whilst demangling strings. since the name mangling formats allow for an infinite level of recursion, it's possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault πŸ’€. the limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting.

the default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. πŸ™ˆ

  • -g, --debugging β€” display debugging information. this attempts to parse STABS debugging format information stored in the file and print it out using a C like syntax. if no STABS debugging was found, this option falls back on the -W option to print any DWARF information in the file.
  • -e, --debugging-tags β€” like -g, but the information is generated in a format compatible with the ctags tool.
  • -d, --disassemble, --disassemble=symbol β€” display the assembler mnemonics for the machine instructions from the input file. this option only disassembles those sections which are expected to contain instructions. if the optional symbol argument is given (perhaps multiple times), then display the assembler mnemonics starting at (all the) symbol. if symbol is a function name then disassembly will stop at the end of the function, otherwise it will stop when the next symbol is encountered. if there are no matches for any symbol then nothing will be displayed. πŸ€·β™€οΈ

note: if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info files will be read in and used when disassembling.

  • -D, --disassemble-all β€” like -d, but disassemble the contents of all non-empty non-bss sections, not just those expected to contain instructions. -j may be used to select specific sections.

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's 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.

note: if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info files will be read in and used when disassembling.

  • --no-addresses β€” when disassembling, don't print addresses on each line or for symbols and relocation offsets. in combination with --no-show-raw-insn this may be useful for comparing compiler output. πŸ‘‘
  • --prefix-addresses β€” when disassembling, print the complete address on each line. this is the older disassembly format.
  • -EB, -EL, --endian={big|little} β€” 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.
  • -f, --file-headers β€” display summary information from the overall header of each of the objfile files.
  • -F, --file-offsets β€” 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.
  • --file-start-context β€” 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 β€” 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.

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.

  • -H, --help β€” print a summary of the options to objdump and exit. short and sweet πŸŽ€
  • -i, --info β€” display a list showing all architectures and object formats available for specification with -b or -m.
  • -j name, --section=name β€” display information for section name. this option may be specified multiple times.
  • -L, --process-links β€” display the contents of non-debug sections found in separate debuginfo files that are linked to the main file. this option automatically implies the -WK option, and only sections requested by other command line options will be displayed.

okay that's part 1, and we are not done β€” more options are coming, so don't go anywhere bestie πŸ¦‹

  • -l, --line-numbers β€” bestie, this one labels the display with the filename and source line numbers that go with the object code or relocs shown (it pulls that from debugging information ✨). Heads up tho: it's only useful with -d, -D, or -r. Alone it's giving nothing πŸ’…
  • -m machine, --architecture=machine β€” tells objdump which architecture to use when disassembling object files. Super handy when the object file doesn't describe its own architecture info, like S-records 🫢. Wanna see what architectures you've got? That's the -i option, babes.

For most architectures you can hand over an architecture name and a machine name, separated by a colon. So like foo:bar would refer to the bar machine type in the foo architecture 🌸. Very helpful if objdump was configured to support multiple architectures.

If the target is an ARM architecture then this switch does an extra little thing: it restricts the disassembly to only those instructions supported by the architecture specified by machine. And if you need this switch because the input file has no architecture info, but you still wanna disassemble all the instructions β€” use -marm. periodt πŸ’–

  • -M options, --disassembler-options=options β€” passes target-specific info to the disassembler. Only supported on some targets, iykyk πŸ™ˆ. Need more than one disassembler option? Stack up multiple -M options, or squish them 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 double precision FP instructions 🧚. On top of that, you can have all the immediates printed in hexadecimal using hex. By default, the short immediates get printed in decimal, while the long immediate values are printed as hexadecimal.

cpu=... lets you enforce a particular ISA when disassembling instructions, overriding the -m value or whatever is sitting in the ELF file πŸ”₯. This might be useful to select ARC EM or HS ISA, because architecture is the same for those two and the disassembler relies on private ELF header data to decide if code is for EM or HS. You can specify this option multiple times β€” only the latest value will be used. Valid values are the same as for the assembler -mcpu=... option.

If the target is an ARM architecture, this switch picks which register name set the disassembler uses πŸ‘‘. Specifying -M reg-names-std (the default) selects 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 selects the name set used by the ARM Procedure Call Standard, whilst specifying -M reg-names-raw just uses 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 πŸ’€. Useful when you're trying to disassemble thumb code produced by other compilers.

For AArch64 targets this switch sets whether instructions are disassembled as the most general instruction using the -M no-aliases option, or whether instruction notes should be generated as comments in the disassembly using -M notes ✨.

For the x86, some of these options duplicate functions of the -m switch, but they allow finer grained control:

  • "x86-64", "i386", "i8086" β€” select disassembly for the given architecture.
  • "intel", "att" β€” select between intel syntax mode and AT&T syntax mode.
  • "amd64", "intel64" β€” select between AMD64 ISA and Intel64 ISA.
  • "intel-mnemonic", "att-mnemonic" β€” select between intel mnemonic mode and AT&T mnemonic mode. Note: "intel-mnemonic" implies "intel" and "att-mnemonic" implies "att".
  • "addr64", "addr32", "addr16", "data32", "data16" β€” specify the default address size and operand size. These five options get overridden if "x86-64", "i386" or "i8086" appear later in the option string.
  • "suffix" β€” when in AT&T mode, and also for a limited set of instructions when in Intel mode, instructs the disassembler to print a mnemonic suffix even when the suffix could be inferred by the operands, or, for certain instructions, the execution mode's defaults.

For PowerPC, the -M argument raw selects disassembly of hardware insns rather than aliases 🌈. For example, you'll 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, e200z2, e200z4, e300, e500, e500mc, e500mc64, e500x2, e5500, e6500, efs, power4, power5, power6, power7, power8, power9, power10, power11, ppc, ppc32, ppc64, ppc64bridge, ppcps, pwr, pwr2, pwr4, pwr5, pwr5x, pwr6, pwr7, pwr8, pwr9, pwr10, pwr11, pwrx, titan, vle, and future πŸ’–. 32 and 64 modify the default or a prior CPU selection, disabling and enabling 64-bit insns respectively. In addition, altivec, any, lsp, htm, vsx, spe and spe2 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 file headers, but the result again may not be as you expect.

For RISC-V, the following options are supported:

  • "max" β€” disassemble without checking architecture string. This is a best effort mode, so for overlapping ISA extensions the first match (possibly incorrect in a given context) will be used to decode the instruction. It's useful if the ELF file doesn't expose ISA string, preventing automatic ISA subset deduction, and the default fallback ISA string ("rv64gc") doesn't cover all instructions in the binary πŸ¦‹.
  • "numeric" β€” print numeric register names, rather than ABI names (e.g., print "x2" instead of "sp").
  • "no-aliases" β€” disassemble only into canonical instructions. For example, compressed instructions will be represented as such ("addi sp,sp,-128" will be "c.addi16sp sp,-128").
  • "priv-spec=SPEC" β€” print the CSR according to the chosen privilege spec version (e.g., 1.10, 1.11, 1.12, 1.13).

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

  • "no-aliases" β€” 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.
  • "msa" β€” disassemble MSA instructions.
  • "virt" β€” disassemble the virtualization ASE instructions.
  • "xpa" β€” disassemble the eXtended Physical Address (XPA) ASE instructions.
  • "gpr-names=ABI" β€” 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" β€” print FPR (floating-point register) names as appropriate for the specified ABI. By default, FPR numbers are printed rather than names.
  • "cp0-names=ARCH" β€” 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" β€” 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" β€” print GPR and FPR names as appropriate for the selected ABI.
  • "reg-names=ARCH" β€” 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 πŸ’œ. 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 to the rest of the function being wrongly disassembled. not me crying over a misdecoded function entry mask 😭

  • -p, --private-headers β€” prints 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 at all. rip.
  • -P options, --private=options β€” also prints information that is specific to the object file format ✨. Here 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:

  • "header"
  • "aout"
  • "sections"
  • "syms"
  • "relocs"
  • "lineno,"
  • "loader"
  • "except"
  • "typchk"
  • "traceback"
  • "toc"
  • "ldinfo"

And if we're talking PE files, bestie, the menu is way shorter:

  • "header"
  • "sections"
Heads up tho 🫢 not every object format is gonna support this option. Like, ELF specifically? It literally does not use it. Not its vibe. Don't come for it.

✨ -r / --reloc ✨

  • -r, --reloc β€” prints out the relocation entries of the file. And plot twist: if you use it together with -d or -D, the relocations get printed interspersed with the disassembly. Like, woven through it. Chef's kiss honestly πŸ’…

✨ -R / --dynamic-reloc ✨

  • -R, --dynamic-reloc β€” prints the dynamic relocation entries of the file. This one only really means something for dynamic objects β€” think certain types of shared libraries, yk? And just like -r, if you pair it with -d or -D, the relocations come out interspersed with the disassembly. Same energy. πŸ¦‹
Note, bestie: objdump does not support displaying RELR type relocations. Like, at all. If that's what you need, the readelf program can show them. Sorry, that's just the tea β˜•

✨ -s / --full-contents ✨

  • -s, --full-contents β€” displays the full contents of sections. Super commonly used together with -j when you wanna request specific sections. By default it shows all non-empty, non-bss sections. And by default, any compressed section shows up in its compressed form. Wanna see it decompressed instead? Add the -Z option to the command line. Slay. ✨

✨ -S / --source ✨

  • -S, --source β€” displays source code intermixed with the disassembly, if that's possible. It implies -d. πŸŽ€

✨ --show-all-symbols ✨

  • --show-all-symbols β€” when disassembling, this shows you all the symbols that match a given address, not just the first one. Because sometimes one address has main character energy and multiple names. πŸ‘‘

✨ --source-comment[=txt] ✨

  • --source-comment[=txt] β€” basically like -S, except every single source code line gets displayed with a prefix of txt. Usually txt is gonna be a comment string, which is handy for telling the assembler code apart from the source code. And if you don't provide txt? It just defaults to "# " β€” that's a hash followed by a space, bestie. 🫢

✨ --prefix=prefix ✨

  • *--prefix=prefix* β€” specifies a prefix to add to the absolute paths when it's used with -S. πŸ’–

✨ --prefix-strip=level ✨

  • *--prefix-strip=level* β€” tells it how many initial directory names to strip off the hardwired absolute paths. Lowkey important: this has no effect without --prefix=prefix. So don't even try it alone. πŸ™ˆ

✨ --show-raw-insn ✨

  • --show-raw-insn β€” when disassembling instructions, print the instruction in hex as well as in symbolic form. Fun fact: this is the default, except when --prefix-addresses is being used. 😌

✨ --no-show-raw-insn ✨

  • --no-show-raw-insn β€” when disassembling instructions, don't print the instruction bytes. And this one is the default when --prefix-addresses is used. Mirror image, iconic. πŸͺž

✨ --insn-width=width ✨

  • *--insn-width=width* β€” displays width bytes on a single line when disassembling instructions. Keep it tidy bestie πŸ“

✨ --visualize-jumps[=color|=extended-color|=off] ✨

  • --visualize-jumps[=color|=extended-color|=off] β€” visualizes jumps that stay inside a function by drawing ASCII art</> between the start and target addresses. Cute, right?? The optional =color argument adds color to the output using simple terminal colors. Or, if you're feeling fancy, the =extended-color argument adds color using 8bit colors β€” but ngl those might not work on all terminals. πŸ’€

And if you ever need to disable the visualize-jumps option after it's already been enabled? Just use visualize-jumps=off. Simple as. ✨

✨ --disassembler-color=… ✨

  • --disassembler-color=off
  • --disassembler-color=terminal
  • --disassembler-color=on|color|colour
  • --disassembler-color=extended|extended-color|extended-colour

These enable or disable the use of colored syntax highlighting in disassembly output. The default behaviour is determined via a configure time option. Now, a lil warning: not all architectures support colored syntax highlighting, and depending on the terminal you're using, the colored output might not actually be legible. 😭

  • The on argument adds colors using simple terminal colors.
  • The terminal argument does the same thing, but only if the output device is a terminal.
  • The extended-color argument is similar to on, but it uses 8-bit colors. These may not work on all terminals. πŸ™ˆ
  • The off argument disables colored disassembly. Periodt.

✨ -W / --dwarf ✨

  • -W[lLiaprmfFsoORtUuTgAckK]
  • --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]

Displays the contents of the DWARF debug sections in the file, if any are present. Compressed debug sections get automatically (and temporarily!) decompressed before they're displayed. Cute.

If one or more of the optional letters or words follows the switch, then only those type(s) of data get dumped. Here's the whole lineup, and what each letter/word refers to:

  • "a", "=abbrev" β€” displays the contents of the .debug_abbrev section. πŸŽ€
  • "A", "=addr" β€” displays the contents of the .debug_addr section. πŸ’–
  • "c", "=cu_index" β€” displays the contents of the .debug_cu_index and/or .debug_tu_index sections. πŸ¦‹
  • "f", "=frames" β€” displays the raw contents of a .debug_frame section. 🌸
  • "F", "=frames-interp" β€” displays the interpreted contents of a .debug_frame section. ✨
  • "g", "=gdb_index" β€” displays the contents of the .gdb_index and/or .debug_names sections. πŸ‘‘
  • "i", "=info" β€” displays the contents of the .debug_info section. Note: the output from this option can also be restricted by using the --dwarf-depth and --dwarf-start options. πŸ’…
  • "k", "=links" β€” displays the contents of the .gnu_debuglink, .gnu_debugaltlink and .debug_sup sections, if any of them are present. It also displays any links to separate dwarf object files (dwo), if they're specified by the DW_AT_GNU_dwo_name or DW_AT_dwo_name attributes in the .debug_info section. πŸ”—
  • "K", "=follow-links" β€” displays the contents of any selected debug sections that are found in linked, separate debug info file(s). Warning bestie: this can result in multiple versions of the same debug section being displayed if it exists in more than one file. 😡

Also, when displaying DWARF attributes, if a form is found that references the separate debug info file, then the referenced contents will also be displayed. 🫢

Note β€” in some distributions this option is enabled by default. It can be disabled via the N debug option. The default can be chosen when configuring the binutils via the --enable-follow-debug-links=yes or --enable-follow-debug-links=no options. If those aren't used, then the default is to enable the following of debug links.
Note β€” if support for the debuginfod protocol was enabled when the binutils were built, then this option will also include an attempt to contact any debuginfod servers mentioned in the DEBUGINFOD_URLS environment variable. And this could take some time to resolve, fr fr. This behaviour can be disabled via the =do-not-use-debuginfod debug option. ⏳
  • "N", "=no-follow-links" β€” disables the following of links to separate debug info files. 🚫
  • "D", "=use-debuginfod" β€” enables contacting debuginfod servers if there's a need to follow debug links. This is the default behaviour. ✨
  • "E", "=do-not-use-debuginfod" β€” disables contacting debuginfod servers when there's a need to follow debug links. πŸ™ˆ
  • "l", "=rawline" β€” displays the contents of the .debug_line section in a raw format. πŸ“„
  • "L", "=decodedline" β€” displays the interpreted contents of the .debug_line section. 🧚
  • "m", "=macro" β€” displays the contents of the .debug_macro and/or .debug_macinfo sections. πŸ“
  • "o", "=loc" β€” displays the contents of the .debug_loc and/or .debug_loclists sections. πŸ’œ
  • "O", "=str-offsets" β€” displays the contents of the .debug_str_offsets section. ⭐
  • "p", "=pubnames" β€” displays the contents of the .debug_pubnames and/or .debug_gnu_pubnames sections. 🌈
  • "r", "=aranges" β€” displays the contents of the .debug_aranges section. πŸ“
  • "R", "=Ranges" β€” displays the contents of the .debug_ranges and/or .debug_rnglists sections. πŸ“
  • "s", "=str" β€” displays the contents of the .debug_str, .debug_line_str and/or .debug_str_offsets sections. πŸŽ€
  • "t", "=pubtype" β€” displays the contents of the .debug_pubtypes and/or .debug_gnu_pubtypes sections. πŸ’–
  • "T", "=trace_aranges" β€” displays the contents of the .trace_aranges section. πŸ¦‹
  • "u", "=trace_abbrev" β€” displays the contents of the .trace_abbrev section. 🌸
  • "U", "=trace_info" β€” displays the contents of the .trace_info section. ✨
Note, bestie: displaying the contents of .debug_static_funcs, .debug_static_vars and debug_weaknames sections is not currently supported. Soz πŸ’€

✨ --dwarf-depth=n ✨

  • --dwarf-depth=n β€” limits the dump of the ".debug_info" section to n children. This is only useful with --debug-dump=info. The default is to print *all the DIEs; and 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. And the range for n is zero-based. πŸ“š

✨ --dwarf-start=n ✨

  • --dwarf-start=n β€” prints *only DIEs beginning with the DIE numbered *n. Again, this is only useful with --debug-dump=info. πŸ‘‘

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. 🌿

And you can use this in conjunction with --dwarf-depth. πŸ’…

✨ --dwarf-check ✨

  • --dwarf-check β€” enables additional checks for consistency of Dwarf information. Gotta make sure everything's giving what it's supposed to give ✨

✨ --ctf[=section] ✨

  • --ctf[=section] β€” displays the contents of the specified CTF section. CTF sections themselves contain many subsections, and all of them get displayed in order. 🌈

By default, it displays the name of the section named .ctf, which is the name emitted by ld. πŸ’–

  • --ctf-parent=member β€” okay so when a CTF section has ambiguously-defined types, it's actually an archive of many CTF dictionaries, and they all inherit from one dictionary that holds the unambiguous types. That member is named .ctf by default (same name as the section holding it), but a linker can rename it at link time using the ctf_link_set_memb_name_changer function. So if you're staring at a CTF archive that a name-changer-using linker made, --ctf-parent lets you say what the parent archive member is actually called now. πŸ’…
  • --ctf-parent-section=section β€” this one lets you pick a completely different section for the CTF parent dictionary (the unambiguous types one) than the one holding the child dictionaries (the ambiguous remainder). The linker doesn't emit ELF objects shaped like this, but some third-party linkers might. It's also handy for inspecting CTF written out as multiple raw files so you can compose them with objcopy, which can drop them into different ELF sections but not into different members of a single CTF dict. 🫢
  • --sframe[=section] β€” display the contents of the specified SFrame section. By default it shows the section named .sframe, which is the name ld emits. ✨
  • -G, --stabs β€” display the full contents of any sections requested. Displays the contents of the .stab, .stab.index and .stab.excl sections from an ELF file. Ngl this is only useful on systems (like Solaris 2.0) where .stab debugging symbol-table entries are carried inside an ELF section. In most other file formats, debugging symbol-table entries are interleaved with linkage symbols and you'll see them in the --syms output instead. πŸ¦‹
  • --start-address=address β€” start displaying data at the specified address. This affects the output of the -d, -r and -s options. 🌸
  • --stop-address=address β€” stop displaying data at the specified address. This affects the output of the -d, -r and -s options. πŸŽ€
  • -t, --syms β€” print the symbol table entries of the file. It's similar to what nm gives you, though the display format is different. The format of the output depends on 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 auxiliary entries associated with the symbol. The last two fields are the symbol's value and its name.

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 referred 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 there.

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:

  • "l" "g" "u" "!" β€” 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" β€” the symbol is weak (w) or strong (a space).
  • "C" β€” the symbol denotes a constructor (C) or an ordinary symbol (a space).
  • "W" β€” 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" "i" β€” 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" "D" β€” the symbol is a debugging symbol (d) or a dynamic symbol (D) or a normal symbol (a space).
  • "F" "f" "O" β€” the symbol is the name of a function (F) or a file (f) or an object (O) or just a normal symbol (a space).
  • -T, --dynamic-syms β€” print the dynamic symbol table entries of the file. This is only meaningful for dynamic objects, like certain types of shared libraries. It's similar to what nm gives you when you pass it the -D (--dynamic) option. The output format is similar to what --syms produces, except an extra field gets 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. πŸ‘‘
  • --special-syms β€” 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. πŸ™ˆ
  • -U [d|i|l|e|x|h], --unicode=[default|invalid|locale|escape|hex|highlight] β€” controls the display of UTF-8 encoded multibyte characters in strings. The default (--unicode=default) is to give them no special treatment. The --unicode=locale option displays the sequence in the current locale, which may or may not support them. The options --unicode=hex and --unicode=invalid display them as hex byte sequences enclosed by either angle brackets or curly braces. The --unicode=escape option displays them as escape sequences (\uxxxx) and the --unicode=highlight option displays them as escape sequences highlighted in red (if supported by the output device). The colouring is intended to draw attention to the presence of unicode sequences where they might not be expected. vibe check passed 🌈
  • -V, --version β€” print the version number of objdump and exit. πŸŽ€
  • -x, --all-headers β€” 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. ✨
  • -w, --wide β€” format some lines for output devices that have more than 80 columns. Also do not truncate symbol names when they are displayed. πŸ’–
  • -z, --disassemble-zeroes β€” normally the disassembly output will skip blocks of zeroes. This option directs the disassembler to disassemble those blocks, just like any other data. πŸ’€
  • -Z, --decompress β€” the -Z option is meant to be used in conunction with the -s option. It instructs objdump to decompress any compressed sections before displaying their contents. 🫢
  • @file β€” 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. 🧚

πŸ‘€ SEE ALSO

nm(1), readelf(1), and the Info entries for binutils. Go read them bestie, they're iconic too. πŸ’œ


Copyright (c) 1991-2026 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". 🌸


and that's the whole page, bestie!! this lil masterpiece is binutils-2.46.1, dated 2026-09-07, and it lives at OBJDUMP(1). no cap, you're officially a disassembly girlie now. slay, hydrate, and go dump some object files. πŸ’…βœ¨πŸ¦‹

πŸ“¦ where this page comes from
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