OBJDUMP(1)

💖 OBJDUMP(1) 💖

GNU Development Tools

🌸 NAME 🌸

objdump — display information from object files, bestie ✨

✨ 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 💅

Okay so objdump pulls up information about one or more object files. The options are literally the controls for what particular information gets displayed 👑

This info is mostly useful to programmers who are working on the compilation tools — not so much for programmers who just want their program to compile and work, iykyk.

objfile... are the object files to be examined, bestie. When you specify archives, objdump shows information on each of the member object files. Slay 🫶

---

🎀 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,-P,-r,-R,-s,-S,-t,-T,-V,-x must be given. Periodt 💅

• -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 info you could list with ar tv, objdump -a shows the object file format of each archive member. Iconic 🔥
• --adjust-vma=offset — 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 using a format that can not represent section addresses, such as a.out.
• -b bfdname, --target=bfdname — Specify that the object-code format for the object files is bfdname. This option may not be necessary; objdump can automatically recognize many formats. Lowkey convenient 💖

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 compiler. Name glow-up fr fr ✨
• --recurse-limit, --no-recurse-limit, --recursion-limit, --no-recursion-limit — 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 is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault 😭 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. So like… be careful, bestie 💀

• -g, --debugging — 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. Cute fallback behavior tbh 🎀
• -e, --debugging-tags — Like -g, but the information is generated in a format compatible with the ctags tool. Nickname energy 🌸
• -d, --disassemble, --disassemble=symbol — 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. No matches = no show, periodt 🙈

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 — 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. Main character energy 👑

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 is 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 — 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. Clean and minimal vibe check ✨
• --prefix-addresses — When disassembling, print the complete address on each line. This is the older disassembly format. Retro moment 💅
• -EB, -EL, --endian={big|little} — 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 — Display summary information from the overall header of each of the objfile files. Header tea ☕
• -F, --file-offsets — 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. Receipts for days 🧾
• --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. Context extension unlocked 🦋
• -h, --section-headers, --headers — Display summary information from the section headers of the object file. Section header era 💖

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. Flag drama, but make it informative 🌈

• -H, --help — Print a summary of the options to objdump and exit. Tiny helper moment 🫶
• -i, --info — Display a list showing all architectures and object formats available for specification with -b or -m. The directory of possibilities, lowkey 🌟
• -j name, --section=name — Display information for section name. This option may be specified multiple times. Multiple sections? We love options 🎀
• -L, --process-links — 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. Auto-imply slay ✨
• -l, --line-numbers — this one tags the display with the filename and source line numbers that match up to the object code or relocs being shown, using the debugging info in the file. 💖 Lowkey only useful with -d, -D, or -r though, so don't come for me if it does nothing on its own.
• -m machine, --architecture=machine — tells objdump which architecture to use when it's disassembling. Genuinely a lifesaver when your object files don't describe their own architecture, like S-records do their own thing. You can peep the whole list of available architectures with the -i option. 👑

For most architectures you can hand it an architecture name and a machine name, glued together with a colon. So foo:bar would mean the bar machine type inside the foo architecture. Super helpful when objdump has been configured to support multiple architectures at once. 🦋

Now, if your target is an ARM architecture this switch does extra work — it restricts disassembly to only those instructions supported by the architecture you named in machine. And if you need this switch because the input file has no architecture info at all, but you still wanna disassemble everything? Use -marm. No cap.

• -M options, --disassembler-options=options — passes target-specific info down to the disassembler. Only some targets support this, so vibe check your target first. Need more than one disassembler option? Either stack multiple -M options or shove them all into one comma-separated list. ✨

ARC: dsp controls printing of DSP instructions, spfp selects printing of FPX single precision FP instructions, dpfp selects printing of FPX double precision FP instructions, quarkse_em selects printing of special QuarkSE-EM instructions, fpuda selects printing of double precision assist instructions, fpus selects printing of FPU single precision FP instructions, and fpud selects printing of FPU double precision FP instructions. On top of that, you can have all the immediates printed in hex with hex. By default, short immediates print in decimal while long immediate values print as hex. 🍓

cpu=... lets you enforce a particular ISA when disassembling, overriding the -m value or whatever's sitting in the ELF file. Handy for picking ARC EM or HS ISA, because the architecture is the same for both and the disassembler relies on private ELF header data to decide if the code is EM or HS. You can specify this multiple times — only the latest value gets used, bestie. Valid values are the same as for the assembler's -mcpu=... option.

ARM: this switch picks which register name set gets used during disassembly. -M reg-names-std (the default) gives you the register names from ARM's instruction set docs, except register 13 is called sp, register 14 is called lr, and register 15 is called pc. -M reg-names-apcs gives the name set used by the ARM Procedure Call Standard, and -M reg-names-raw just uses r followed by the register number. 💅

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

Still on ARM — you can force the disassembler to read all instructions as Thumb instructions with --disassembler-options=force-thumb. Iconic for when you're trying to disassemble thumb code that some other compiler produced. 🧚

AArch64: this switch sets whether instructions are disassembled as the most general instruction with -M no-aliases, or whether instruction notes get generated as comments in the disassembly with -M notes.

x86: some of these duplicate what -m does, but with finer grained control. Obsessed.

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

PowerPC: the -M argument raw selects disassembly of hardware insns instead of aliases. So you'll see "rlwinm" instead of "clrlwi", and "addi" instead of "li". All the -m arguments for gas that select a CPU are supported, and they 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. The 32 and 64 modify the default or a prior CPU selection, disabling and enabling 64-bit insns respectively. Also, 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 where an opcode has two different meanings or different arguments, you may not see the disassembly you expect. And if you disassemble without giving a CPU selection, a default gets chosen from info BFD gleans from the object file headers — but again, the result may not be what you expect. 😭

RISC-V: these are the supported options:

• "max" — disassemble without checking the architecture string. Best effort mode, so for overlapping ISA extensions the first match (possibly incorrect in a given context) gets used to decode the instruction. Useful if the ELF file doesn't expose an ISA string, which prevents automatic ISA subset deduction, and the default fallback ISA string ("rv64gc") doesn't cover all the instructions in the binary.
• "numeric" — print numeric register names rather than ABI names (e.g., print "x2" instead of "sp").
• "no-aliases" — disassemble only into canonical instructions. So compressed instructions get represented as such ("addi sp,sp,-128" becomes "c.addi16sp sp,-128").
• "priv-spec=SPEC" — print the CSR according to the chosen privilege spec version (e.g., 1.10, 1.11, 1.12, 1.13).

MIPS: this option controls printing of instruction mnemonic names and register names in disassembled instructions. You can pick multiple from the list below as a comma separated string, and invalid options are just ignored (rude, but okay):

• "no-aliases" — 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" — disassemble MSA instructions.
• "virt" — disassemble the virtualization ASE instructions.
• "xpa" — disassemble the eXtended Physical Address (XPA) ASE instructions.
• "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 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. 🌸

VAX: you can specify function entry addresses with -M entry:0xf00ba. Use it multiple times to properly disassemble VAX binary files that don't contain symbol tables (like ROM dumps). In those 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. 💀

• -p, --private-headers — prints information specific to the object file format. Exactly what gets printed depends on the object file format — and for some object file formats, no additional information is printed at all. 🙈
• -P options, --private=options — prints information specific to the object file format. The options argument is a comma separated list that depends on the format (the lists of options are shown with the help).

For XCOFF, the available options are:

---

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

For PE the menu is a whole lot shorter, bestie — these are the only options:

• "header"
• "sections"

Not every object format vibes with this option, jsyk. ELF in particular does not use it at all, like not even a little 💀

• -r, --reloc — prints the relocation entries of the file. And if you pair it with -d or -D, the relocations get printed interspersed with the disassembly — like a little sprinkle of relocations between the instructions ✨
• -R, --dynamic-reloc — prints the dynamic relocation entries of the file. This one only really makes sense for dynamic objects, like certain types of shared libraries. Same deal as -r: if you use it with -d or -D, the relocations come out interspersed with the disassembly.

Heads up: objdump does not support displaying RELR type relocations. If you need those, the readelf program can show them for you, no cap.

• -s, --full-contents — displays the full contents of sections, and it's honestly so good paired with -j when you wanna request specific sections only. By default it shows all non-empty non-bss sections. And by default any compressed section gets shown in its compressed form — so if you wanna peek at the contents decompressed, just add the -Z option to the command line 🫶
• -S, --source — displays source code intermixed with the disassembly, if it can. Implies -d (so you're getting disassembly whether you asked or not).
• --show-all-symbols — when disassembling, shows all the symbols matching a given address, not just the first one. Main character energy for every symbol at that address 👑
• --source-comment[=txt] — basically -S but every single source code line gets a prefix of txt. Usually txt is a comment string so you can tell the assembler code apart from the source code. If you don't give txt, the default is "# " — that's a hash followed by a space 💅
• --prefix=prefix — specifies prefix to add to the absolute paths when you're using it with -S.
• --prefix-strip=level — tells it how many initial directory names to strip off the hardwired absolute paths. Lowkey does nothing without --prefix=prefix, fr fr.
• --show-raw-insn — when disassembling instructions, prints the instruction in hex as well as in symbolic form. This is the default, except when --prefix-addresses is used.
• --no-show-raw-insn — when disassembling instructions, doesn't print the instruction bytes. This is the default when --prefix-addresses is used.
• --insn-width=width — displays width bytes on a single line when disassembling instructions.
• --visualize-jumps[=color|=extended-color|=off] — visualizes jumps that stay inside a function by drawing ASCII art between the start and target addresses. Obsessed, honestly. The optional =color argument adds color to the output using simple terminal colors. Alternatively the =extended-color argument adds color using 8bit colors — but those might not work on all terminals, so 👀

And if you ever need to disable the visualize-jumps option after it's already been enabled, just use visualize-jumps=off. Easy.

• --disassembler-color=off
• --disassembler-color=terminal
• --disassembler-color=on|color|colour
• --disassembler-color=extended|extended-color|extended-colour — enables or disables colored syntax highlighting in disassembly output. The default behaviour is decided via a configure time option. Note bestie: 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, 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.

The off argument disables colored disassembly. Periodt.

• -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 decompressed (temporarily) before they're displayed, which is honestly so considerate. If one or more of the optional letters or words follows the switch, then only those type(s) of data get dumped. The letters and words refer to the following info:
  • "a", "=abbrev" — displays the contents of the .debug_abbrev section.
  • "A", "=addr" — displays the contents of the .debug_addr section.
  • "c", "=cu_index" — displays the contents of the .debug_cu_index and/or .debug_tu_index sections.
  • "f", "=frames" — displays the raw contents of a .debug_frame section.
  • "F", "=frames-interp" — displays the interpreted contents of a .debug_frame section.
  • "g", "=gdb_index" — displays the contents of the .gdb_index and/or .debug_names sections.
  • "i", "=info" — 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, iykyk.
  • "k", "=links" — displays the contents of the .gnu_debuglink, .gnu_debugaltlink and .debug_sup sections, if any of them are present. 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.
  • "K", "=follow-links" — displays the contents of any selected debug sections found in linked, separate debug info file(s). This can result in multiple versions of the same debug section being displayed if it exists in more than one file, jsyk.

Plus, when displaying DWARF attributes, if a form is found that references the separate debug info file, then the referenced contents also get displayed. ✨

Note: 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: 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. That could take some time to resolve 😭 This behaviour can be disabled via the =do-not-use-debuginfod debug option.

• "N", "=no-follow-links" — disables the following of links to separate debug info files.
• "D", "=use-debuginfod" — enables contacting debuginfod servers if there's a need to follow debug links. This is the default behaviour.
• "E", "=do-not-use-debuginfod" — disables contacting debuginfod servers when there's a need to follow debug links.
• "l", "=rawline" — displays the contents of the .debug_line section in a raw format.
• "L", "=decodedline" — displays the interpreted contents of the .debug_line section.
• "m", "=macro" — displays the contents of the .debug_macro and/or .debug_macinfo sections.
• "o", "=loc" — displays the contents of the .debug_loc and/or .debug_loclists sections.
• "O", "=str-offsets" — displays the contents of the .debug_str_offsets section.
• "p", "=pubnames" — displays the contents of the .debug_pubnames and/or .debug_gnu_pubnames sections.
• "r", "=aranges" — displays the contents of the .debug_aranges section.
• "R", "=Ranges" — displays the contents of the .debug_ranges and/or .debug_rnglists sections.
• "s", "=str" — displays the contents of the .debug_str, .debug_line_str and/or .debug_str_offsets sections.
• "t", "=pubtype" — displays the contents of the .debug_pubtypes and/or .debug_gnu_pubtypes sections.
• "T", "=trace_aranges" — displays the contents of the .trace_aranges section.
• "u", "=trace_abbrev" — displays the contents of the .trace_abbrev section.
• "U", "=trace_info" — displays the contents of the .trace_info section.

Note: displaying the contents of .debug_static_funcs, .debug_static_vars and debug_weaknames sections is not currently supported. Sad but true 🙈

• --dwarf-depth=n — limits the dump of the .debug_info section to n children. Only useful with --debug-dump=info. The default is to print all DIEs, and the special value 0 for n will also have that effect.

With a non-zero value for n, DIEs at or deeper than n levels will not be printed. The range for n is zero-based.

• --dwarf-start=n — prints only DIEs beginning with the DIE numbered n. Only useful with --debug-dump=info.

If specified, this option suppresses printing of any header information and all DIEs before the DIE numbered n. Only siblings and children of the specified DIE get printed.

You can use it together with --dwarf-depth 💅

• --dwarf-check — enables additional checks for consistency of Dwarf information. Safety girl behaviour, love that.
• --ctf[=section] — displays the contents of the specified CTF section. CTF sections themselves contain many subsections, and all of them are displayed in order.

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

• --ctf-parent=member — okay so if the CTF section has ambiguously-defined types, it's actually an archive of many CTF dictionaries, and every one of them inherits from a single dictionary holding the unambiguous types 💅 That parent member is named .ctf by default, just like the section it lives in — but you can change that name at link time with the ctf_link_set_memb_name_changer function. So when you're staring at CTF archives made by a linker that used the name changer to rename the parent archive member, --ctf-parent is your girl: it lets you specify the name used for the parent. 🫶
• --ctf-parent-section=section — this one lets you pick a completely different section for the CTF parent dictionary (the unambiguous types one) than the section holding the child dictionaries (the ambiguous remainder). Fr fr the linker does not emit ELF objects structured like this, but some third-party linkers may 👀 It's also lowkey convenient for inspecting CTF written out as multiple raw files so you can compose them with objcopy — which can put them in different ELF sections but not in different members of a single CTF dict.
• --sframe[=section] — display the contents of the specified SFrame section. By default, display the name of the section named .sframe, which is the name emitted by ld. ✨
• -G, --stabs — display the full contents of any sections requested, and display the contents of the .stab, .stab.index and .stab.excl sections from an ELF file. This is only useful on systems (such as Solaris 2.0) where .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 they show up in the --syms output instead. 💀
• --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 also affects the output of the -d, -r and -s options. (Yes bestie, they're a matching set 🎀)
• -t, --syms — print the symbol table entries of the file. Similar to what nm gives you, although the display format is different. The output format 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 — those 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 — get comfy, this is the main character lore:

• "l", "g", "u", "!" — 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" — the symbol is weak (w) or strong (a space).
• "C" — the symbol denotes a constructor (C) or an ordinary symbol (a space).
• "W" — 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" — 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" — the symbol is a debugging symbol (d) or a dynamic symbol (D) or a normal symbol (a space).
• "F", "f", "O" — 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 — print the dynamic symbol table entries of the file. This is only meaningful for dynamic objects, such as certain types of shared libraries. Similar to the info nm gives you when you pass it the -D (--dynamic) option. ✨

The output format is similar to what --syms produces, except an extra field is 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. 🎀

• --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. 🙈
• -U [d|i|l|e|x|h], --unicode=[default|invalid|locale|escape|hex|highlight] — 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. 💅

• -V, --version — print the version number of objdump and exit. Bye bestie! 👋
• -x, --all-headers — 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. The whole buffet, no cap. 🍓
• -w, --wide — format some lines for output devices that have more than 80 columns. Also, do not truncate symbol names when they are displayed. 🌈
• -z, --disassemble-zeroes — normally the disassembly output skips blocks of zeroes. This option directs the disassembler to disassemble those blocks, just like any other data. (Zeroes deserve screen time too 💀)
• -Z, --decompress — 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 — 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. 🌀

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🌸 SEE ALSO 🌸

nm(1), readelf(1), and the Info entries for binutils. Go say hi to the neighbours, they're iconic too 💖

👑 COPYRIGHT 👑

Copyright (c) 1991-2025 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".

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Okay that's the whole page bestie, you ate it all up 💅 this lil doc is from binutils-2.45.1, dated 2026-01-23, and it's the OBJDUMP(1) manual page — go forth and dump some objects, you've got this 🫶✨