1 \input texinfo @c -*- Texinfo -*-
2 @setfilename binutils.info
8 * Binutils: (binutils). The GNU binary utilities "ar", "objcopy",
9 "objdump", "nm", "nlmconv", "size",
10 "strings", "strip", and "ranlib".
16 Copyright @copyright{} 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
18 Permission is granted to make and distribute verbatim copies of
19 this manual provided the copyright notice and this permission notice
20 are preserved on all copies.
23 Permission is granted to process this file through TeX and print the
24 results, provided the printed document carries a copying permission
25 notice identical to this one except for the removal of this paragraph
26 (this paragraph not being relevant to the printed manual).
30 Permission is granted to copy and distribute modified versions of this
31 manual under the conditions for verbatim copying, provided also that
32 the entire resulting derived work is distributed under the terms of a
33 permission notice identical to this one.
35 Permission is granted to copy and distribute translations of this manual
36 into another language, under the above conditions for modified versions.
41 @c This file documents the GNU binary utilities "ar", "ld", "objcopy",
42 @c "objdump", "nm", "size", "strings", "strip", and "ranlib".
44 @c Copyright (C) 1991, 1992, 1993 Free Software Foundation, Inc.
46 @c This text may be freely distributed under the terms of the GNU
47 @c General Public License.
50 @setchapternewpage odd
51 @settitle GNU Binary Utilities
54 @title The GNU Binary Utilities
55 @subtitle Version @value{VERSION}
58 @author Roland H. Pesch
59 @author Jeffrey M. Osier
60 @author Cygnus Support
64 {\parskip=0pt \hfill Cygnus Support\par \hfill
65 \TeX{}info \texinfoversion\par }
68 @vskip 0pt plus 1filll
69 Copyright @copyright{} 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
71 Permission is granted to make and distribute verbatim copies of
72 this manual provided the copyright notice and this permission notice
73 are preserved on all copies.
75 Permission is granted to copy and distribute modified versions of this
76 manual under the conditions for verbatim copying, provided also that
77 the entire resulting derived work is distributed under the terms of a
78 permission notice identical to this one.
80 Permission is granted to copy and distribute translations of this manual
81 into another language, under the above conditions for modified versions.
88 This brief manual contains preliminary documentation for the GNU binary
89 utilities (collectively version @value{VERSION}):
94 Create, modify, and extract from archives
97 List symbols from object files
100 Copy and translate object files
103 Display information from object files
106 Generate index to archive contents
109 List file section sizes and total size
112 List printable strings from files
118 Demangle encoded C++ symbols
121 Convert object code into a Netware Loadable Module
126 * ar:: Create, modify, and extract from archives
127 * nm:: List symbols from object files
128 * objcopy:: Copy and translate object files
129 * objdump:: Display information from object files
130 * ranlib:: Generate index to archive contents
131 * size:: List section sizes and total size
132 * strings:: List printable strings from files
133 * strip:: Discard symbols
134 * c++filt:: Filter to demangle encoded C++ symbols
135 * nlmconv:: Converts object code into an NLM
136 * Selecting The Target System:: How these utilities determine the target.
145 @cindex collections of files
147 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
148 ar -M [ <mri-script ]
151 The GNU @code{ar} program creates, modifies, and extracts from
152 archives. An @dfn{archive} is a single file holding a collection of
153 other files in a structure that makes it possible to retrieve
154 the original individual files (called @dfn{members} of the archive).
156 The original files' contents, mode (permissions), timestamp, owner, and
157 group are preserved in the archive, and can be restored on
161 GNU @code{ar} can maintain archives whose members have names of any
162 length; however, depending on how @code{ar} is configured on your
163 system, a limit on member-name length may be imposed for compatibility
164 with archive formats maintained with other tools. If it exists, the
165 limit is often 15 characters (typical of formats related to a.out) or 16
166 characters (typical of formats related to coff).
169 @code{ar} is considered a binary utility because archives of this sort
170 are most often used as @dfn{libraries} holding commonly needed
174 @code{ar} creates an index to the symbols defined in relocatable
175 object modules in the archive when you specify the modifier @samp{s}.
176 Once created, this index is updated in the archive whenever @code{ar}
177 makes a change to its contents (save for the @samp{q} update operation).
178 An archive with such an index speeds up linking to the library, and
179 allows routines in the library to call each other without regard to
180 their placement in the archive.
182 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index
183 table. If an archive lacks the table, another form of @code{ar} called
184 @code{ranlib} can be used to add just the table.
186 @cindex compatibility, @code{ar}
187 @cindex @code{ar} compatibility
188 GNU @code{ar} is designed to be compatible with two different
189 facilities. You can control its activity using command-line options,
190 like the different varieties of @code{ar} on Unix systems; or, if you
191 specify the single command-line option @samp{-M}, you can control it
192 with a script supplied via standard input, like the MRI ``librarian''
196 * ar cmdline:: Controlling @code{ar} on the command line
197 * ar scripts:: Controlling @code{ar} with a script
202 @section Controlling @code{ar} on the command line
205 ar [-]@var{p}[@var{mod} [@var{relpos}]] @var{archive} [@var{member}@dots{}]
208 @cindex Unix compatibility, @code{ar}
209 When you use @code{ar} in the Unix style, @code{ar} insists on at least two
210 arguments to execute: one keyletter specifying the @emph{operation}
211 (optionally accompanied by other keyletters specifying
212 @emph{modifiers}), and the archive name to act on.
214 Most operations can also accept further @var{member} arguments,
215 specifying particular files to operate on.
217 GNU @code{ar} allows you to mix the operation code @var{p} and modifier
218 flags @var{mod} in any order, within the first command-line argument.
220 If you wish, you may begin the first command-line argument with a
223 @cindex operations on archive
224 The @var{p} keyletter specifies what operation to execute; it may be
225 any of the following, but you must specify only one of them:
229 @cindex deleting from archive
230 @emph{Delete} modules from the archive. Specify the names of modules to
231 be deleted as @var{member}@dots{}; the archive is untouched if you
232 specify no files to delete.
234 If you specify the @samp{v} modifier, @code{ar} lists each module
238 @cindex moving in archive
239 Use this operation to @emph{move} members in an archive.
241 The ordering of members in an archive can make a difference in how
242 programs are linked using the library, if a symbol is defined in more
245 If no modifiers are used with @code{m}, any members you name in the
246 @var{member} arguments are moved to the @emph{end} of the archive;
247 you can use the @samp{a}, @samp{b}, or @samp{i} modifiers to move them to a
248 specified place instead.
251 @cindex printing from archive
252 @emph{Print} the specified members of the archive, to the standard
253 output file. If the @samp{v} modifier is specified, show the member
254 name before copying its contents to standard output.
256 If you specify no @var{member} arguments, all the files in the archive are
260 @cindex quick append to archive
261 @emph{Quick append}; add the files @var{member}@dots{} to the end of
262 @var{archive}, without checking for replacement.
264 The modifiers @samp{a}, @samp{b}, and @samp{i} do @emph{not} affect this
265 operation; new members are always placed at the end of the archive.
267 The modifier @samp{v} makes @code{ar} list each file as it is appended.
269 Since the point of this operation is speed, the archive's symbol table
270 index is not updated, even if it already existed; you can use @samp{ar s} or
271 @code{ranlib} explicitly to update the symbol table index.
274 @cindex replacement in archive
275 Insert the files @var{member}@dots{} into @var{archive} (with
276 @emph{replacement}). This operation differs from @samp{q} in that any
277 previously existing members are deleted if their names match those being
280 If one of the files named in @var{member}@dots{} does not exist, @code{ar}
281 displays an error message, and leaves undisturbed any existing members
282 of the archive matching that name.
284 By default, new members are added at the end of the file; but you may
285 use one of the modifiers @samp{a}, @samp{b}, or @samp{i} to request
286 placement relative to some existing member.
288 The modifier @samp{v} used with this operation elicits a line of
289 output for each file inserted, along with one of the letters @samp{a} or
290 @samp{r} to indicate whether the file was appended (no old member
291 deleted) or replaced.
294 @cindex contents of archive
295 Display a @emph{table} listing the contents of @var{archive}, or those
296 of the files listed in @var{member}@dots{} that are present in the
297 archive. Normally only the member name is shown; if you also want to
298 see the modes (permissions), timestamp, owner, group, and size, you can
299 request that by also specifying the @samp{v} modifier.
301 If you do not specify a @var{member}, all files in the archive
304 @cindex repeated names in archive
305 @cindex name duplication in archive
306 If there is more than one file with the same name (say, @samp{fie}) in
307 an archive (say @samp{b.a}), @samp{ar t b.a fie} lists only the
308 first instance; to see them all, you must ask for a complete
309 listing---in our example, @samp{ar t b.a}.
310 @c WRS only; per Gumby, this is implementation-dependent, and in a more
311 @c recent case in fact works the other way.
314 @cindex extract from archive
315 @emph{Extract} members (named @var{member}) from the archive. You can
316 use the @samp{v} modifier with this operation, to request that
317 @code{ar} list each name as it extracts it.
319 If you do not specify a @var{member}, all files in the archive
324 A number of modifiers (@var{mod}) may immediately follow the @var{p}
325 keyletter, to specify variations on an operation's behavior:
329 @cindex relative placement in archive
330 Add new files @emph{after} an existing member of the
331 archive. If you use the modifier @samp{a}, the name of an existing archive
332 member must be present as the @var{relpos} argument, before the
333 @var{archive} specification.
336 Add new files @emph{before} an existing member of the
337 archive. If you use the modifier @samp{b}, the name of an existing archive
338 member must be present as the @var{relpos} argument, before the
339 @var{archive} specification. (same as @samp{i}).
342 @cindex creating archives
343 @emph{Create} the archive. The specified @var{archive} is always
344 created if it did not exist, when you request an update. But a warning is
345 issued unless you specify in advance that you expect to create it, by
349 Truncate names in the archive. GNU @code{ar} will normally permit file
350 names of any length. This will cause it to create archives which are
351 not compatible with the native @code{ar} program on some systems. If
352 this is a concern, the @samp{f} modifier may be used to truncate file
353 names when putting them in the archive.
356 Insert new files @emph{before} an existing member of the
357 archive. If you use the modifier @samp{i}, the name of an existing archive
358 member must be present as the @var{relpos} argument, before the
359 @var{archive} specification. (same as @samp{b}).
362 This modifier is accepted but not used.
363 @c whaffor ar l modifier??? presumably compat; with
364 @c what???---pesch@@cygnus.com, 25jan91
367 @cindex dates in archive
368 Preserve the @emph{original} dates of members when extracting them. If
369 you do not specify this modifier, files extracted from the archive
370 are stamped with the time of extraction.
373 @cindex writing archive index
374 Write an object-file index into the archive, or update an existing one,
375 even if no other change is made to the archive. You may use this modifier
376 flag either with any operation, or alone. Running @samp{ar s} on an
377 archive is equivalent to running @samp{ranlib} on it.
380 @cindex updating an archive
381 Normally, @samp{ar r}@dots{} inserts all files
382 listed into the archive. If you would like to insert @emph{only} those
383 of the files you list that are newer than existing members of the same
384 names, use this modifier. The @samp{u} modifier is allowed only for the
385 operation @samp{r} (replace). In particular, the combination @samp{qu} is
386 not allowed, since checking the timestamps would lose any speed
387 advantage from the operation @samp{q}.
390 This modifier requests the @emph{verbose} version of an operation. Many
391 operations display additional information, such as filenames processed,
392 when the modifier @samp{v} is appended.
395 This modifier shows the version number of @code{ar}.
399 @section Controlling @code{ar} with a script
402 ar -M [ <@var{script} ]
405 @cindex MRI compatibility, @code{ar}
406 @cindex scripts, @code{ar}
407 If you use the single command-line option @samp{-M} with @code{ar}, you
408 can control its operation with a rudimentary command language. This
409 form of @code{ar} operates interactively if standard input is coming
410 directly from a terminal. During interactive use, @code{ar} prompts for
411 input (the prompt is @samp{AR >}), and continues executing even after
412 errors. If you redirect standard input to a script file, no prompts are
413 issued, and @code{ar} abandons execution (with a nonzero exit code)
416 The @code{ar} command language is @emph{not} designed to be equivalent
417 to the command-line options; in fact, it provides somewhat less control
418 over archives. The only purpose of the command language is to ease the
419 transition to GNU @code{ar} for developers who already have scripts
420 written for the MRI ``librarian'' program.
422 The syntax for the @code{ar} command language is straightforward:
425 commands are recognized in upper or lower case; for example, @code{LIST}
426 is the same as @code{list}. In the following descriptions, commands are
427 shown in upper case for clarity.
430 a single command may appear on each line; it is the first word on the
434 empty lines are allowed, and have no effect.
437 comments are allowed; text after either of the characters @samp{*}
438 or @samp{;} is ignored.
441 Whenever you use a list of names as part of the argument to an @code{ar}
442 command, you can separate the individual names with either commas or
443 blanks. Commas are shown in the explanations below, for clarity.
446 @samp{+} is used as a line continuation character; if @samp{+} appears
447 at the end of a line, the text on the following line is considered part
448 of the current command.
451 Here are the commands you can use in @code{ar} scripts, or when using
452 @code{ar} interactively. Three of them have special significance:
454 @code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
455 a temporary file required for most of the other commands.
457 @code{SAVE} commits the changes so far specified by the script. Prior
458 to @code{SAVE}, commands affect only the temporary copy of the current
462 @item ADDLIB @var{archive}
463 @itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
464 Add all the contents of @var{archive} (or, if specified, each named
465 @var{module} from @var{archive}) to the current archive.
467 Requires prior use of @code{OPEN} or @code{CREATE}.
469 @item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
470 @c FIXME! w/Replacement?? If so, like "ar r @var{archive} @var{names}"
471 @c else like "ar q..."
472 Add each named @var{member} as a module in the current archive.
474 Requires prior use of @code{OPEN} or @code{CREATE}.
477 Discard the contents of the current archive, cancelling the effect of
478 any operations since the last @code{SAVE}. May be executed (with no
479 effect) even if no current archive is specified.
481 @item CREATE @var{archive}
482 Creates an archive, and makes it the current archive (required for many
483 other commands). The new archive is created with a temporary name; it
484 is not actually saved as @var{archive} until you use @code{SAVE}.
485 You can overwrite existing archives; similarly, the contents of any
486 existing file named @var{archive} will not be destroyed until @code{SAVE}.
488 @item DELETE @var{module}, @var{module}, @dots{} @var{module}
489 Delete each listed @var{module} from the current archive; equivalent to
490 @samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.
492 Requires prior use of @code{OPEN} or @code{CREATE}.
494 @item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
495 @itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
496 List each named @var{module} present in @var{archive}. The separate
497 command @code{VERBOSE} specifies the form of the output: when verbose
498 output is off, output is like that of @samp{ar -t @var{archive}
499 @var{module}@dots{}}. When verbose output is on, the listing is like
500 @samp{ar -tv @var{archive} @var{module}@dots{}}.
502 Output normally goes to the standard output stream; however, if you
503 specify @var{outputfile} as a final argument, @code{ar} directs the
507 Exit from @code{ar}, with a @code{0} exit code to indicate successful
508 completion. This command does not save the output file; if you have
509 changed the current archive since the last @code{SAVE} command, those
512 @item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
513 Extract each named @var{module} from the current archive, writing them
514 into the current directory as separate files. Equivalent to @samp{ar -x
515 @var{archive} @var{module}@dots{}}.
517 Requires prior use of @code{OPEN} or @code{CREATE}.
520 @c FIXME Tokens but no commands???
527 Display full contents of the current archive, in ``verbose'' style
528 regardless of the state of @code{VERBOSE}. The effect is like @samp{ar
529 tv @var{archive}}). (This single command is a GNU @code{ld}
530 enhancement, rather than present for MRI compatibility.)
532 Requires prior use of @code{OPEN} or @code{CREATE}.
534 @item OPEN @var{archive}
535 Opens an existing archive for use as the current archive (required for
536 many other commands). Any changes as the result of subsequent commands
537 will not actually affect @var{archive} until you next use @code{SAVE}.
539 @item REPLACE @var{module}, @var{module}, @dots{} @var{module}
540 In the current archive, replace each existing @var{module} (named in
541 the @code{REPLACE} arguments) from files in the current working directory.
542 To execute this command without errors, both the file, and the module in
543 the current archive, must exist.
545 Requires prior use of @code{OPEN} or @code{CREATE}.
548 Toggle an internal flag governing the output from @code{DIRECTORY}.
549 When the flag is on, @code{DIRECTORY} output matches output from
550 @samp{ar -tv }@dots{}.
553 Commit your changes to the current archive, and actually save it as a
554 file with the name specified in the last @code{CREATE} or @code{OPEN}
557 Requires prior use of @code{OPEN} or @code{CREATE}.
566 The GNU linker @code{ld} is now described in a separate manual.
567 @xref{Top,, Overview,, Using LD: the GNU linker}.
576 nm [ -a | --debug-syms ] [ -g | --extern-only ]
577 [ -B ] [ -C | --demangle ] [ -D | --dynamic ]
578 [ -s | --print-armap ] [ -A | -o | --print-file-name ]
579 [ -n | -v | --numeric-sort ] [ -p | --no-sort ]
580 [ -r | --reverse-sort ] [ --size-sort ] [ -u | --undefined-only ]
581 [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
582 [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
583 [ --no-demangle ] [ -V | --version ] [ --help ] [ @var{objfile}@dots{} ]
586 GNU @code{nm} lists the symbols from object files @var{objfile}@dots{}.
587 If no object files are listed as arguments, @code{nm} assumes
590 For each symbol, @code{nm} shows:
594 The symbol value, in the radix selected by options (see below), or
595 hexadecimal by default.
598 The symbol type. At least the following types are used; others are, as
599 well, depending on the object file format. If lowercase, the symbol is
600 local; if uppercase, the symbol is global (external).
602 @c Some more detail on exactly what these symbol types are used for
609 BSS (uninitialized data).
631 The long and short forms of options, shown here as alternatives, are
637 @itemx --print-file-name
638 @cindex input file name
640 @cindex source file name
641 Precede each symbol by the name of the input file (or archive element)
642 in which it was found, rather than identifying the input file once only,
643 before all of its symbols.
647 @cindex debugging symbols
648 Display all symbols, even debugger-only symbols; normally these are not
652 @cindex @code{nm} format
653 @cindex @code{nm} compatibility
654 The same as @samp{--format=bsd} (for compatibility with the MIPS @code{nm}).
658 @cindex demangling C++ symbols
659 Decode (@dfn{demangle}) low-level symbol names into user-level names.
660 Besides removing any initial underscore prepended by the system, this
661 makes C++ function names readable. @xref{c++filt}, for more information
665 Do not demangle low-level symbol names. This is the default.
669 @cindex dynamic symbols
670 Display the dynamic symbols rather than the normal symbols. This is
671 only meaningful for dynamic objects, such as certain types of shared
674 @item -f @var{format}
675 @itemx --format=@var{format}
676 @cindex @code{nm} format
677 @cindex @code{nm} compatibility
678 Use the output format @var{format}, which can be @code{bsd},
679 @code{sysv}, or @code{posix}. The default is @code{bsd}.
680 Only the first character of @var{format} is significant; it can be
681 either upper or lower case.
685 @cindex external symbols
686 Display only external symbols.
690 @itemx --numeric-sort
691 Sort symbols numerically by their addresses, rather than alphabetically
696 @cindex sorting symbols
697 Do not bother to sort the symbols in any order; print them in the order
702 Use the POSIX.2 standard output format instead of the default format.
703 Equivalent to @samp{-f posix}.
707 @cindex symbol index, listing
708 When listing symbols from archive members, include the index: a mapping
709 (stored in the archive by @code{ar} or @code{ranlib}) of which modules
710 contain definitions for which names.
713 @itemx --reverse-sort
714 Reverse the order of the sort (whether numeric or alphabetic); let the
718 Sort symbols by size. The size is computed as the difference between
719 the value of the symbol and the value of the symbol with the next higher
720 value. The size of the symbol is printed, rather than the value.
723 @itemx --radix=@var{radix}
724 Use @var{radix} as the radix for printing the symbol values. It must be
725 @samp{d} for decimal, @samp{o} for octal, or @samp{x} for hexadecimal.
727 @item --target=@var{bfdname}
728 @cindex object code format
729 Specify an object code format other than your system's default format.
730 @xref{Target Selection}, for more information.
733 @itemx --undefined-only
734 @cindex external symbols
735 @cindex undefined symbols
736 Display only undefined symbols (those external to each object file).
740 Show the version number of @code{nm} and exit.
743 Show a summary of the options to @code{nm} and exit.
750 objcopy [ -F @var{bfdname} | --target=@var{bfdname} ]
751 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
752 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
753 [ -S | --strip-all ] [ -g | --strip-debug ]
754 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
755 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
756 [ -x | --discard-all ] [ -X | --discard-locals ]
757 [ -b @var{byte} | --byte=@var{byte} ]
758 [ -i @var{interleave} | --interleave=@var{interleave} ]
759 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
760 [ --gap-fill=@var{val} ] [ --pad-to=@var{address} ]
761 [ --set-start=@var{val} ] [ --adjust-start=@var{incr} ]
762 [ --adjust-vma=@var{incr} ]
763 [ --adjust-section-vma=@var{section}@{=,+,-@}@var{val} ]
764 [ --adjust-warnings ] [ --no-adjust-warnings ]
765 [ --set-section-flags=@var{section}=@var{flags} ]
766 [ --add-section=@var{sectionname}=@var{filename} ]
767 [ -v | --verbose ] [ -V | --version ] [ --help ]
768 @var{infile} [@var{outfile}]
771 The @sc{gnu} @code{objcopy} utility copies the contents of an object
772 file to another. @code{objcopy} uses the @sc{gnu} @sc{bfd} Library to
773 read and write the object files. It can write the destination object
774 file in a format different from that of the source object file. The
775 exact behavior of @code{objcopy} is controlled by command-line options.
777 @code{objcopy} creates temporary files to do its translations and
778 deletes them afterward. @code{objcopy} uses @sc{bfd} to do all its
779 translation work; it has access to all the formats described in @sc{bfd}
780 and thus is able to recognize most formats without being told
781 explicitly. @xref{BFD,,BFD,ld.info,Using LD}.
783 @code{objcopy} can be used to generate S-records by using an output
784 target of @samp{srec} (e.g., use @samp{-O srec}).
786 @code{objcopy} can be used to generate a raw binary file by using an
787 output target of @samp{binary} (e.g., use @samp{-O binary}). When
788 @code{objcopy} generates a raw binary file, it will essentially produce
789 a memory dump of the contents of the input object file. All symbols and
790 relocation information will be discarded. The memory dump will start at
791 the virtual address of the lowest section copied into the output file.
793 When generating an S-record or a raw binary file, it may be helpful to
794 use @samp{-S} to remove sections containing debugging information. In
795 some cases @samp{-R} will be useful to remove sections which contain
796 information which is not needed by the binary file.
801 The source and output files, respectively.
802 If you do not specify @var{outfile}, @code{objcopy} creates a
803 temporary file and destructively renames the result with
804 the name of @var{infile}.
806 @item -I @var{bfdname}
807 @itemx --input-target=@var{bfdname}
808 Consider the source file's object format to be @var{bfdname}, rather than
809 attempting to deduce it. @xref{Target Selection}, for more information.
811 @item -O @var{bfdname}
812 @itemx --output-target=@var{bfdname}
813 Write the output file using the object format @var{bfdname}.
814 @xref{Target Selection}, for more information.
816 @item -F @var{bfdname}
817 @itemx --target=@var{bfdname}
818 Use @var{bfdname} as the object format for both the input and the output
819 file; i.e., simply transfer data from source to destination with no
820 translation. @xref{Target Selection}, for more information.
822 @item -R @var{sectionname}
823 @itemx --remove-section=@var{sectionname}
824 Remove any section named @var{sectionname} from the output file. This
825 option may be given more than once. Note that using this option
826 inappropriately may make the output file unusable.
830 Do not copy relocation and symbol information from the source file.
834 Do not copy debugging symbols from the source file.
836 @item --strip-unneeded
837 Strip all symbols that are not needed for relocation processing.
839 @item -K @var{symbolname}
840 @itemx --keep-symbol=@var{symbolname}
841 Copy only symbol @var{symbolname} from the source file. This option may
842 be given more than once.
844 @item -N @var{symbolname}
845 @itemx --strip-symbol=@var{symbolname}
846 Do not copy symbol @var{symbolname} from the source file. This option
847 may be given more than once, and may be combined with strip options
848 other than @code{-K}.
852 Do not copy non-global symbols from the source file.
853 @c FIXME any reason to prefer "non-global" to "local" here?
856 @itemx --discard-locals
857 Do not copy compiler-generated local symbols.
858 (These usually start with @samp{L} or @samp{.}.)
861 @itemx --byte=@var{byte}
862 Keep only every @var{byte}th byte of the input file (header data is not
863 affected). @var{byte} can be in the range from 0 to @var{interleave}-1,
864 where @var{interleave} is given by the @samp{-i} or @samp{--interleave}
865 option, or the default of 4. This option is useful for creating files
866 to program @sc{rom}. It is typically used with an @code{srec} output
869 @item -i @var{interleave}
870 @itemx --interleave=@var{interleave}
871 Only copy one out of every @var{interleave} bytes. Select which byte to
872 copy with the @var{-b} or @samp{--byte} option. The default is 4.
873 @code{objcopy} ignores this option if you do not specify either @samp{-b} or
876 @item --gap-fill @var{val}
877 Fill gaps between sections with @var{val}. This is done by increasing
878 the size of the section with the lower address, and filling in the extra
879 space created with @var{val}.
881 @item --pad-to @var{address}
882 Pad the output file up to the virtual address @var{address}. This is
883 done by increasing the size of the last section. The extra space is
884 filled in with the value specified by @samp{--gap-fill} (default zero).
886 @item --set-start @var{val}
887 Set the address of the new file to @var{val}. Not all object file
888 formats support setting the start address.
890 @item --adjust-start @var{incr}
891 Adjust the start address by adding @var{incr}. Not all object file
892 formats support setting the start address.
894 @item --adjust-vma @var{incr}
895 Adjust the address of all sections, as well as the start address, by
896 adding @var{incr}. Some object file formats do not permit section
897 addresses to be changed arbitrarily. Note that this does not relocate
898 the sections; if the program expects sections to be loaded at a certain
899 address, and this option is used to change the sections such that they
900 are loaded at a different address, the program may fail.
902 @item --adjust-section-vma @var{section}@{=,+,-@}@var{val}
903 Set or adjust the address of the named @var{section}. If @samp{=} is
904 used, the section address is set to @var{val}. Otherwise, @var{val} is
905 added to or subtracted from the section address. See the comments under
906 @samp{--adjust-vma}, above. If @var{section} does not exist in the
907 input file, a warning will be issued, unless @samp{--no-adjust-warnings}
910 @item --adjust-warnings
911 If @samp{--adjust-section-vma} is used, and the named section does not
912 exist, issue a warning. This is the default.
914 @item --no-adjust-warnings
915 Do not issue a warning if @samp{--adjust-section-vma} is used, even if
916 the named section does not exist.
918 @item --set-section-flags @var{section}=@var{flags}
919 Set the flags for the named section. The @var{flags} argument is a
920 comma separated string of flag names. The recognized names are
921 @samp{alloc}, @samp{load}, @samp{readonly}, @samp{code}, @samp{data},
922 and @samp{rom}. Not all flags are meaningful for all object file
925 @item --add-section @var{sectionname}=@var{filename}
926 Add a new section named @var{sectionname} while copying the file. The
927 contents of the new section are taken from the file @var{filename}. The
928 size of the section will be the size of the file. This option only
929 works on file formats which can support sections with arbitrary names.
933 Show the version number of @code{objcopy}.
937 Verbose output: list all object files modified. In the case of
938 archives, @samp{objcopy -V} lists all members of the archive.
941 Show a summary of the options to @code{objcopy}.
947 @cindex object file information
951 objdump [ -a | --archive-headers ]
952 [ -b @var{bfdname} | --target=@var{bfdname} ]
953 [ -d | --disassemble ] [ -D | --disassemble-all ]
954 [ -f | --file-headers ]
955 [ -h | --section-headers | --headers ] [ -i | --info ]
956 [ -j @var{section} | --section=@var{section} ]
957 [ -l | --line-numbers ] [ -S | --source ]
958 [ -m @var{machine} | --architecture=@var{machine} ]
959 [ -r | --reloc ] [ -R | --dynamic-reloc ]
960 [ -s | --full-contents ] [ --stabs ]
961 [ -t | --syms ] [ -T | --dynamic-syms ] [ -x | --all-headers ]
962 [ -w | --wide ] [ --version ] [ --help ] @var{objfile}@dots{}
965 @code{objdump} displays information about one or more object files.
966 The options control what particular information to display. This
967 information is mostly useful to programmers who are working on the
968 compilation tools, as opposed to programmers who just want their
969 program to compile and work.
971 @var{objfile}@dots{} are the object files to be examined. When you
972 specify archives, @code{objdump} shows information on each of the member
975 The long and short forms of options, shown here as alternatives, are
976 equivalent. At least one option besides @samp{-l} must be given.
980 @itemx --archive-header
981 @cindex archive headers
982 If any of the @var{objfile} files are archives, display the archive
983 header information (in a format similar to @samp{ls -l}). Besides the
984 information you could list with @samp{ar tv}, @samp{objdump -a} shows
985 the object file format of each archive member.
987 @item -b @var{bfdname}
988 @itemx --target=@var{bfdname}
989 @cindex object code format
990 Specify that the object-code format for the object files is
991 @var{bfdname}. This option may not be necessary; @var{objdump} can
992 automatically recognize many formats.
996 objdump -b oasys -m vax -h fu.o
999 displays summary information from the section headers (@samp{-h}) of
1000 @file{fu.o}, which is explicitly identified (@samp{-m}) as a VAX object
1001 file in the format produced by Oasys compilers. You can list the
1002 formats available with the @samp{-i} option.
1003 @xref{Target Selection}, for more information.
1006 @itemx --disassemble
1007 @cindex disassembling object code
1008 @cindex machine instructions
1009 Display the assembler mnemonics for the machine instructions from
1010 @var{objfile}. This option only disassembles those sections which are
1011 expected to contain instructions.
1014 @itemx --disassemble-all
1015 Like @samp{-d}, but disassemble the contents of all sections, not just
1016 those expected to contain instructions.
1019 @itemx --file-header
1020 @cindex object file header
1021 Display summary information from the overall header of
1022 each of the @var{objfile} files.
1025 @itemx --section-header
1027 @cindex section headers
1028 Display summary information from the section headers of the
1031 File segments may be relocated to nonstandard addresses, for example by
1032 using the @samp{-Ttext}, @samp{-Tdata}, or @samp{-Tbss} options to
1033 @code{ld}. However, some object file formats, such as a.out, do not
1034 store the starting address of the file segments. In those situations,
1035 although @code{ld} relocates the sections correctly, using @samp{objdump
1036 -h} to list the file section headers cannot show the correct addresses.
1037 Instead, it shows the usual addresses, which are implicit for the
1041 Print a summary of the options to @code{objdump} and exit.
1045 @cindex architectures available
1046 @cindex object formats available
1047 Display a list showing all architectures and object formats available
1048 for specification with @samp{-b} or @samp{-m}.
1051 @itemx --section=@var{name}
1052 @cindex section information
1053 Display information only for section @var{name}.
1056 @itemx --line-numbers
1057 @cindex source filenames for object files
1058 Label the display (using debugging information) with the filename
1059 and source line numbers corresponding to the object code shown.
1060 Only useful with @samp{-d} or @samp{-D}.
1062 @item -m @var{machine}
1063 @itemx --architecture=@var{machine}
1064 @cindex architecture
1065 Specify that the object files @var{objfile} are for architecture
1066 @var{machine}. You can list available architectures using the @samp{-i}
1071 @cindex relocation entries, in object file
1072 Print the relocation entries of the file. If used with @samp{-d} or
1073 @samp{-D}, the relocations are printed interspersed with the
1077 @itemx --dynamic-reloc
1078 @cindex dynamic relocation entries, in object file
1079 Print the dynamic relocation entries of the file. This is only
1080 meaningful for dynamic objects, such as certain types of shared
1084 @itemx --full-contents
1085 @cindex sections, full contents
1086 @cindex object file sections
1087 Display the full contents of any sections requested.
1091 @cindex source disassembly
1092 @cindex disassembly, with source
1093 Display source code intermixed with disassembly, if possible. Implies
1099 @cindex debug symbols
1100 @cindex ELF object file format
1101 Display the full contents of any sections requested. Display the
1102 contents of the .stab and .stab.index and .stab.excl sections from an
1103 ELF file. This is only useful on systems (such as Solaris 2.0) in which
1104 @code{.stab} debugging symbol-table entries are carried in an ELF
1105 section. In most other file formats, debugging symbol-table entries are
1106 interleaved with linkage symbols, and are visible in the @samp{--syms}
1111 @cindex symbol table entries, printing
1112 Print the symbol table entries of the file.
1113 This is similar to the information provided by the @samp{nm} program.
1116 @itemx --dynamic-syms
1117 @cindex dynamic symbol table entries, printing
1118 Print the dynamic symbol table entries of the file. This is only
1119 meaningful for dynamic objects, such as certain types of shared
1120 libraries. This is similar to the information provided by the @samp{nm}
1121 program when given the @samp{-D} (@samp{--dynamic}) option.
1124 Print the version number of @code{objdump} and exit.
1128 @cindex all header information, object file
1129 @cindex header information, all
1130 Display all available header information, including the symbol table and
1131 relocation entries. Using @samp{-x} is equivalent to specifying all of
1132 @samp{-a -f -h -r -t}.
1136 @cindex wide output, printing
1137 Format some lines for output devices that have more than 80 columns.
1144 @cindex archive contents
1145 @cindex symbol index
1148 ranlib [-vV] @var{archive}
1151 @code{ranlib} generates an index to the contents of an archive and
1152 stores it in the archive. The index lists each symbol defined by a
1153 member of an archive that is a relocatable object file.
1155 You may use @samp{nm -s} or @samp{nm --print-armap} to list this index.
1157 An archive with such an index speeds up linking to the library and
1158 allows routines in the library to call each other without regard to
1159 their placement in the archive.
1161 The GNU @code{ranlib} program is another form of GNU @code{ar}; running
1162 @code{ranlib} is completely equivalent to executing @samp{ar -s}.
1168 Show the version number of @code{ranlib}.
1175 @cindex section sizes
1178 size [ -A | -B | --format=@var{compatibility} ]
1179 [ --help ] [ -d | -o | -x | --radix=@var{number} ]
1180 [ --target=@var{bfdname} ] [ -V | --version ]
1181 @var{objfile}@dots{}
1184 The GNU @code{size} utility lists the section sizes---and the total
1185 size---for each of the object or archive files @var{objfile} in its
1186 argument list. By default, one line of output is generated for each
1187 object file or each module in an archive.
1189 @var{objfile}@dots{} are the object files to be examined.
1191 The command line options have the following meanings:
1196 @itemx --format=@var{compatibility}
1197 @cindex @code{size} display format
1198 Using one of these options, you can choose whether the output from GNU
1199 @code{size} resembles output from System V @code{size} (using @samp{-A},
1200 or @samp{--format=sysv}), or Berkeley @code{size} (using @samp{-B}, or
1201 @samp{--format=berkeley}). The default is the one-line format similar to
1203 @c Bonus for doc-source readers: you can also say --format=strange (or
1204 @c anything else that starts with 's') for sysv, and --format=boring (or
1205 @c anything else that starts with 'b') for Berkeley.
1207 Here is an example of the Berkeley (default) format of output from
1210 size --format=Berkeley ranlib size
1211 text data bss dec hex filename
1212 294880 81920 11592 388392 5ed28 ranlib
1213 294880 81920 11888 388688 5ee50 size
1217 This is the same data, but displayed closer to System V conventions:
1220 size --format=SysV ranlib size
1238 Show a summary of acceptable arguments and options.
1243 @itemx --radix=@var{number}
1244 @cindex @code{size} number format
1245 @cindex radix for section sizes
1246 Using one of these options, you can control whether the size of each
1247 section is given in decimal (@samp{-d}, or @samp{--radix=10}); octal
1248 (@samp{-o}, or @samp{--radix=8}); or hexadecimal (@samp{-x}, or
1249 @samp{--radix=16}). In @samp{--radix=@var{number}}, only the three
1250 values (8, 10, 16) are supported. The total size is always given in two
1251 radices; decimal and hexadecimal for @samp{-d} or @samp{-x} output, or
1252 octal and hexadecimal if you're using @samp{-o}.
1254 @item --target=@var{bfdname}
1255 @cindex object code format
1256 Specify that the object-code format for @var{objfile} is
1257 @var{bfdname}. This option may not be necessary; @code{size} can
1258 automatically recognize many formats.
1259 @xref{Target Selection}, for more information.
1263 Display the version number of @code{size}.
1269 @cindex listings strings
1270 @cindex printing strings
1271 @cindex strings, printing
1274 strings [-afov] [-@var{min-len}] [-n @var{min-len}] [-t @var{radix}] [-]
1275 [--all] [--print-file-name] [--bytes=@var{min-len}]
1276 [--radix=@var{radix}] [--target=@var{bfdname}]
1277 [--help] [--version] @var{file}@dots{}
1280 For each @var{file} given, GNU @code{strings} prints the printable
1281 character sequences that are at least 4 characters long (or the number
1282 given with the options below) and are followed by an unprintable
1283 character. By default, it only prints the strings from the initialized
1284 and loaded sections of object files; for other types of files, it prints
1285 the strings from the whole file.
1287 @code{strings} is mainly useful for determining the contents of non-text
1294 Do not scan only the initialized and loaded sections of object files;
1295 scan the whole files.
1298 @itemx --print-file-name
1299 Print the name of the file before each string.
1302 Print a summary of the program usage on the standard output and exit.
1304 @itemx -@var{min-len}
1305 @item -n @var{min-len}
1306 @itemx --bytes=@var{min-len}
1307 Print sequences of characters that are at least @var{min-len} characters
1308 long, instead of the default 4.
1311 Like @samp{-t o}. Some other versions of @code{strings} have @samp{-o}
1312 act like @samp{-t d} instead. Since we can not be compatible with both
1313 ways, we simply chose one.
1315 @item -t @var{radix}
1316 @itemx --radix=@var{radix}
1317 Print the offset within the file before each string. The single
1318 character argument specifies the radix of the offset---@samp{o} for
1319 octal, @samp{x} for hexadecimal, or @samp{d} for decimal.
1321 @item --target=@var{bfdname}
1322 @cindex object code format
1323 Specify an object code format other than your system's default format.
1324 @xref{Target Selection}, for more information.
1328 Print the program version number on the standard output and exit.
1335 @cindex removing symbols
1336 @cindex discarding symbols
1337 @cindex symbols, discarding
1340 strip [ -F @var{bfdname} | --target=@var{bfdname} | --target=@var{bfdname} ]
1341 [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1342 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1343 [ -s | --strip-all ] [ -S | -g | --strip-debug ]
1344 [ -K @var{symbolname} | --keep-symbol=@var{symbolname} ]
1345 [ -N @var{symbolname} | --strip-symbol=@var{symbolname} ]
1346 [ -x | --discard-all ] [ -X | --discard-locals ]
1347 [ -R @var{sectionname} | --remove-section=@var{sectionname} ]
1348 [ -v | --verbose ] [ -V | --version ] [ --help ]
1349 @var{objfile}@dots{}
1352 GNU @code{strip} discards all symbols from object files
1353 @var{objfile}. The list of object files may include archives.
1354 At least one object file must be given.
1356 @code{strip} modifies the files named in its argument,
1357 rather than writing modified copies under different names.
1360 @item -F @var{bfdname}
1361 @itemx --target=@var{bfdname}
1362 Treat the original @var{objfile} as a file with the object
1363 code format @var{bfdname}, and rewrite it in the same format.
1364 @xref{Target Selection}, for more information.
1367 Show a summary of the options to @code{strip} and exit.
1369 @item -I @var{bfdname}
1370 @itemx --input-target=@var{bfdname}
1371 Treat the original @var{objfile} as a file with the object
1372 code format @var{bfdname}.
1373 @xref{Target Selection}, for more information.
1375 @item -O @var{bfdname}
1376 @itemx --output-target=@var{bfdname}
1377 Replace @var{objfile} with a file in the output format @var{bfdname}.
1378 @xref{Target Selection}, for more information.
1380 @item -R @var{sectionname}
1381 @itemx --remove-section=@var{sectionname}
1382 Remove any section named @var{sectionname} from the output file. This
1383 option may be given more than once. Note that using this option
1384 inappropriately may make the output file unusable.
1392 @itemx --strip-debug
1393 Remove debugging symbols only.
1395 @item --strip-unneeded
1396 Remove all symbols that are not needed for relocation processing.
1398 @item -K @var{symbolname}
1399 @itemx --keep-symbol=@var{symbolname}
1400 Keep only symbol @var{symbolname} from the source file. This option may
1401 be given more than once.
1403 @item -N @var{symbolname}
1404 @itemx --strip-symbol=@var{symbolname}
1405 Remove symbol @var{symbolname} from the source file. This option may be
1406 given more than once, and may be combined with strip options other than
1410 @itemx --discard-all
1411 Remove non-global symbols.
1414 @itemx --discard-locals
1415 Remove compiler-generated local symbols.
1416 (These usually start with @samp{L} or @samp{.}.)
1420 Show the version number for @code{strip}.
1424 Verbose output: list all object files modified. In the case of
1425 archives, @samp{strip -v} lists all members of the archive.
1432 @cindex demangling C++ symbols
1435 c++filt [ -_ | --strip-underscores ]
1436 [ -n | --no-strip-underscores ]
1437 [ -s @var{format} | --format=@var{format} ]
1438 [ --help ] [ --version ] [ @var{symbol}@dots{} ]
1441 The C++ language provides function overloading, which means that you can
1442 write many functions with the same name (providing each takes parameters
1443 of different types). All C++ function names are encoded into a
1444 low-level assembly label (this process is known as
1445 @dfn{mangling}). The @code{c++filt} program does the inverse mapping: it
1446 decodes (@dfn{demangles}) low-level names into user-level names so that
1447 the linker can keep these overloaded functions from clashing.
1449 Every alphanumeric word (consisting of letters, digits, underscores,
1450 dollars, or periods) seen in the input is a potential label. If the
1451 label decodes into a C++ name, the C++ name replaces the low-level
1454 You can use @code{c++filt} to decipher individual symbols:
1457 c++filt @var{symbol}
1460 If no @var{symbol} arguments are given, @code{c++filt} reads symbol
1461 names from the standard input and writes the demangled names to the
1462 standard output. All results are printed on the standard output.
1466 @itemx --strip-underscores
1467 On some systems, both the C and C++ compilers put an underscore in front
1468 of every name. For example, the C name @code{foo} gets the low-level
1469 name @code{_foo}. This option removes the initial underscore. Whether
1470 @code{c++filt} removes the underscore by default is target dependent.
1473 @itemx --no-strip-underscores
1474 Do not remove the initial underscore.
1476 @item -s @var{format}
1477 @itemx --format=@var{format}
1478 GNU @code{nm} can decode three different methods of mangling, used by
1479 different C++ compilers. The argument to this option selects which
1484 the one used by the GNU compiler (the default method)
1486 the one used by the Lucid compiler
1488 the one specified by the C++ Annotated Reference Manual
1492 Print a summary of the options to @code{c++filt} and exit.
1495 Print the version number of @code{c++filt} and exit.
1499 @emph{Warning:} @code{c++filt} is a new utility, and the details of its
1500 user interface are subject to change in future releases. In particular,
1501 a command-line option may be required in the the future to decode a name
1502 passed as an argument on the command line; in other words,
1505 c++filt @var{symbol}
1509 may in a future release become
1512 c++filt @var{option} @var{symbol}
1519 @code{nlmconv} converts a relocatable object file into a NetWare
1523 @code{nlmconv} currently works with @samp{i386} object
1524 files in @code{coff}, @sc{elf}, or @code{a.out} format, and @sc{SPARC}
1525 object files in @sc{elf}, or @code{a.out} format@footnote{
1526 @code{nlmconv} should work with any @samp{i386} or @sc{sparc} object
1527 format in the Binary File Descriptor library. It has only been tested
1528 with the above formats.}.
1532 @emph{Warning:} @code{nlmconv} is not always built as part of the binary
1533 utilities, since it is only useful for NLM targets.
1537 nlmconv [ -I @var{bfdname} | --input-target=@var{bfdname} ]
1538 [ -O @var{bfdname} | --output-target=@var{bfdname} ]
1539 [ -T @var{headerfile} | --header-file=@var{headerfile} ]
1540 [ -d | --debug] [ -l @var{linker} | --linker=@var{linker} ]
1541 [ -h | --help ] [ -V | --version ]
1542 @var{infile} @var{outfile}
1545 @code{nlmconv} converts the relocatable @samp{i386} object file
1546 @var{infile} into the NetWare Loadable Module @var{outfile}, optionally
1547 reading @var{headerfile} for NLM header information. For instructions
1548 on writing the NLM command file language used in header files, see the
1549 @samp{linkers} section, @samp{NLMLINK} in particular, of the @cite{NLM
1550 Development and Tools Overview}, which is part of the NLM Software
1551 Developer's Kit (``NLM SDK''), available from Novell, Inc.
1552 @code{nlmconv} uses the @sc{gnu} Binary File Descriptor library to read
1553 @var{infile}; see @ref{BFD,,BFD,ld.info,Using LD}, for
1556 @code{nlmconv} can perform a link step. In other words, you can list
1557 more than one object file for input if you list them in the definitions
1558 file (rather than simply specifying one input file on the command line).
1559 In this case, @code{nlmconv} calls the linker for you.
1562 @item -I @var{bfdname}
1563 @itemx --input-target=@var{bfdname}
1564 Object format of the input file. @code{nlmconv} can usually determine
1565 the format of a given file (so no default is necessary).
1566 @xref{Target Selection}, for more information.
1568 @item -O @var{bfdname}
1569 @itemx --output-target=@var{bfdname}
1570 Object format of the output file. @code{nlmconv} infers the output
1571 format based on the input format, e.g. for a @samp{i386} input file the
1572 output format is @samp{nlm32-i386}.
1573 @xref{Target Selection}, for more information.
1575 @item -T @var{headerfile}
1576 @itemx --header-file=@var{headerfile}
1577 Reads @var{headerfile} for NLM header information. For instructions on
1578 writing the NLM command file language used in header files, see@ see the
1579 @samp{linkers} section, of the @cite{NLM Development and Tools
1580 Overview}, which is part of the NLM Software Developer's Kit, available
1585 Displays (on standard error) the linker command line used by @code{nlmconv}.
1587 @item -l @var{linker}
1588 @itemx --linker=@var{linker}
1589 Use @var{linker} for any linking. @var{linker} can be an abosolute or a
1594 Prints a usage summary.
1598 Prints the version number for @code{nlmconv}.
1601 @node Selecting The Target System
1602 @chapter Selecting the target system
1604 You can specify three aspects of the target system to the @sc{gnu}
1605 binary file utilities, each in several ways:
1615 the linker emulation (which applies to the linker only)
1618 In the following summaries, the lists of ways to specify values are in
1619 order of decreasing precedence. The ways listed first override those
1622 The commands to list valid values only list the values for which the
1623 programs you are running were configured. If they were configured with
1624 @samp{--with-targets=all}, the commands list most of the available
1625 values, but a few are left out; not all targets can be configured in at
1626 once because some of them can only be configured @dfn{native} (on hosts
1627 with the same type as the target system).
1630 * Target Selection::
1631 * Architecture Selection::
1632 * Linker Emulation Selection::
1635 @node Target Selection
1636 @section Target Selection
1638 A @dfn{target} is an object file format. A given target may be
1639 supported for multiple architectures (@pxref{Architecture Selection}).
1640 A target selection may also have variations for different operating
1641 systems or architectures.
1643 The command to list valid target values is @samp{objdump -i}
1644 (the first column of output contains the relevant information).
1646 Some sample values are: @samp{a.out-hp300bsd}, @samp{ecoff-littlemips},
1647 @samp{a.out-sunos-big}.
1649 @subheading @code{objdump} Target
1655 command line option: @samp{-b} or @samp{--target}
1658 environment variable @code{GNUTARGET}
1661 deduced from the input file
1664 @subheading @code{objcopy} and @code{strip} Input Target
1670 command line options: @samp{-I} or @samp{--input-target}, or @samp{-F} or @samp{--target}
1673 environment variable @code{GNUTARGET}
1676 deduced from the input file
1679 @subheading @code{objcopy} and @code{strip} Output Target
1685 command line options: @samp{-O} or @samp{--output-target}, or @samp{-F} or @samp{--target}
1688 the input target (see ``@code{objcopy} and @code{strip} Input Target'' above)
1691 environment variable @code{GNUTARGET}
1694 deduced from the input file
1697 @subheading @code{nm}, @code{size}, and @code{strings} Target
1703 command line option: @samp{--target}
1706 environment variable @code{GNUTARGET}
1709 deduced from the input file
1712 @subheading Linker Input Target
1718 command line option: @samp{-b} or @samp{--format}
1719 (@pxref{Options,,Options,ld.info,Using LD})
1722 script command @code{TARGET}
1723 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1726 environment variable @code{GNUTARGET}
1727 (@pxref{Environment,,Environment,ld.info,Using LD})
1730 the default target of the selected linker emulation
1731 (@pxref{Linker Emulation Selection})
1734 @subheading Linker Output Target
1740 command line option: @samp{-oformat}
1741 (@pxref{Options,,Options,ld.info,Using LD})
1744 script command @code{OUTPUT_FORMAT}
1745 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1748 the linker input target (see ``Linker Input Target'' above)
1751 @node Architecture Selection
1752 @section Architecture selection
1754 An @dfn{architecture} is a type of @sc{cpu} on which an object file is
1755 to run. Its name may contain a colon, separating the name of the
1756 processor family from the name of the particular @sc{cpu}.
1758 The command to list valid architecture values is @samp{objdump -i} (the
1759 second column contains the relevant information).
1761 Sample values: @samp{m68k:68020}, @samp{mips:3000}, @samp{sparc}.
1763 @subheading @code{objdump} Architecture
1769 command line option: @samp{-m} or @samp{--architecture}
1772 deduced from the input file
1775 @subheading @code{objcopy}, @code{nm}, @code{size}, @code{strings} Architecture
1781 deduced from the input file
1784 @subheading Linker Input Architecture
1790 deduced from the input file
1793 @subheading Linker Output Architecture
1799 script command @code{OUTPUT_ARCH}
1800 (@pxref{Option Commands,,Option Commands,ld.info,Using LD})
1803 the default architecture from the linker output target
1804 (@pxref{Target Selection})
1807 @node Linker Emulation Selection
1808 @section Linker emulation selection
1810 A linker @dfn{emulation} is a ``personality'' of the linker, which gives
1811 the linker default values for the other aspects of the target system.
1812 In particular, it consists of
1822 several ``hook'' functions that are run at certain stages of the linking
1823 process to do special things that some targets require
1826 The command to list valid linker emulation values is @samp{ld -V}.
1828 Sample values: @samp{hp300bsd}, @samp{mipslit}, @samp{sun4}.
1834 command line option: @samp{-m}
1835 (@pxref{Options,,Options,ld.info,Using LD})
1838 environment variable @code{LDEMULATION}
1841 compiled-in @code{DEFAULT_EMULATION} from @file{Makefile},
1842 which comes from @code{EMUL} in @file{config/@var{target}.mt}