{ "mode": "man", "parameter": "OBJCOPY", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/OBJCOPY/1/json", "generated": "2026-06-02T21:26:39Z", "synopsis": "objcopy [-F bfdname|--target=bfdname]\n[-I bfdname|--input-target=bfdname]\n[-O bfdname|--output-target=bfdname]\n[-B bfdarch|--binary-architecture=bfdarch]\n[-S|--strip-all]\n[-g|--strip-debug]\n[--strip-unneeded]\n[-K symbolname|--keep-symbol=symbolname]\n[--keep-file-symbols]\n[--keep-section-symbols]\n[-N symbolname|--strip-symbol=symbolname]\n[--strip-unneeded-symbol=symbolname]\n[-G symbolname|--keep-global-symbol=symbolname]\n[--localize-hidden]\n[-L symbolname|--localize-symbol=symbolname]\n[--globalize-symbol=symbolname]\n[--globalize-symbols=filename]\n[-W symbolname|--weaken-symbol=symbolname]\n[-w|--wildcard]\n[-x|--discard-all]\n[-X|--discard-locals]\n[-b byte|--byte=byte]\n[-i [breadth]|--interleave[=breadth]]\n[--interleave-width=width]\n[-j sectionpattern|--only-section=sectionpattern]\n[-R sectionpattern|--remove-section=sectionpattern]\n[--keep-section=sectionpattern]\n[--remove-relocations=sectionpattern]\n[-p|--preserve-dates]\n[-D|--enable-deterministic-archives]\n[-U|--disable-deterministic-archives]\n[--debugging]\n[--gap-fill=val]\n[--pad-to=address]\n[--set-start=val]\n[--adjust-start=incr]\n[--change-addresses=incr]\n[--change-section-address sectionpattern{=,+,-}val]\n[--change-section-lma sectionpattern{=,+,-}val]\n[--change-section-vma sectionpattern{=,+,-}val]\n[--change-warnings] [--no-change-warnings]\n[--set-section-flags sectionpattern=flags]\n[--set-section-alignment sectionpattern=align]\n[--add-section sectionname=filename]\n[--dump-section sectionname=filename]\n[--update-section sectionname=filename]\n[--rename-section oldname=newname[,flags]]\n[--long-section-names {enable,disable,keep}]\n[--change-leading-char] [--remove-leading-char]\n[--reverse-bytes=num]\n[--srec-len=ival] [--srec-forceS3]\n[--redefine-sym old=new]\n[--redefine-syms=filename]\n[--weaken]\n[--keep-symbols=filename]\n[--strip-symbols=filename]\n[--strip-unneeded-symbols=filename]\n[--keep-global-symbols=filename]\n[--localize-symbols=filename]\n[--weaken-symbols=filename]\n[--add-symbol name=[section:]value[,flags]]\n[--alt-machine-code=index]\n[--prefix-symbols=string]\n[--prefix-sections=string]\n[--prefix-alloc-sections=string]\n[--add-gnu-debuglink=path-to-file]\n[--only-keep-debug]\n[--strip-dwo]\n[--extract-dwo]\n[--extract-symbol]\n[--writable-text]\n[--readonly-text]\n[--pure]\n[--impure]\n[--file-alignment=num]\n[--heap=size]\n[--image-base=address]\n[--section-alignment=num]\n[--stack=size]\n[--subsystem=which:major.minor]\n[--compress-debug-sections]\n[--decompress-debug-sections]\n[--elf-stt-common=val]\n[--merge-notes]\n[--no-merge-notes]\n[--verilog-data-width=val]\n[-v|--verbose]\n[-V|--version]\n[--help] [--info]\ninfile [outfile]", "sections": { "NAME": { "content": "objcopy - copy and translate object files\n", "subsections": [] }, "SYNOPSIS": { "content": "objcopy [-F bfdname|--target=bfdname]\n[-I bfdname|--input-target=bfdname]\n[-O bfdname|--output-target=bfdname]\n[-B bfdarch|--binary-architecture=bfdarch]\n[-S|--strip-all]\n[-g|--strip-debug]\n[--strip-unneeded]\n[-K symbolname|--keep-symbol=symbolname]\n[--keep-file-symbols]\n[--keep-section-symbols]\n[-N symbolname|--strip-symbol=symbolname]\n[--strip-unneeded-symbol=symbolname]\n[-G symbolname|--keep-global-symbol=symbolname]\n[--localize-hidden]\n[-L symbolname|--localize-symbol=symbolname]\n[--globalize-symbol=symbolname]\n[--globalize-symbols=filename]\n[-W symbolname|--weaken-symbol=symbolname]\n[-w|--wildcard]\n[-x|--discard-all]\n[-X|--discard-locals]\n[-b byte|--byte=byte]\n[-i [breadth]|--interleave[=breadth]]\n[--interleave-width=width]\n[-j sectionpattern|--only-section=sectionpattern]\n[-R sectionpattern|--remove-section=sectionpattern]\n[--keep-section=sectionpattern]\n[--remove-relocations=sectionpattern]\n[-p|--preserve-dates]\n[-D|--enable-deterministic-archives]\n[-U|--disable-deterministic-archives]\n[--debugging]\n[--gap-fill=val]\n[--pad-to=address]\n[--set-start=val]\n[--adjust-start=incr]\n[--change-addresses=incr]\n[--change-section-address sectionpattern{=,+,-}val]\n[--change-section-lma sectionpattern{=,+,-}val]\n[--change-section-vma sectionpattern{=,+,-}val]\n[--change-warnings] [--no-change-warnings]\n[--set-section-flags sectionpattern=flags]\n[--set-section-alignment sectionpattern=align]\n[--add-section sectionname=filename]\n[--dump-section sectionname=filename]\n[--update-section sectionname=filename]\n[--rename-section oldname=newname[,flags]]\n[--long-section-names {enable,disable,keep}]\n[--change-leading-char] [--remove-leading-char]\n[--reverse-bytes=num]\n[--srec-len=ival] [--srec-forceS3]\n[--redefine-sym old=new]\n[--redefine-syms=filename]\n[--weaken]\n[--keep-symbols=filename]\n[--strip-symbols=filename]\n[--strip-unneeded-symbols=filename]\n[--keep-global-symbols=filename]\n[--localize-symbols=filename]\n[--weaken-symbols=filename]\n[--add-symbol name=[section:]value[,flags]]\n[--alt-machine-code=index]\n[--prefix-symbols=string]\n[--prefix-sections=string]\n[--prefix-alloc-sections=string]\n[--add-gnu-debuglink=path-to-file]\n[--only-keep-debug]\n[--strip-dwo]\n[--extract-dwo]\n[--extract-symbol]\n[--writable-text]\n[--readonly-text]\n[--pure]\n[--impure]\n[--file-alignment=num]\n[--heap=size]\n[--image-base=address]\n[--section-alignment=num]\n[--stack=size]\n[--subsystem=which:major.minor]\n[--compress-debug-sections]\n[--decompress-debug-sections]\n[--elf-stt-common=val]\n[--merge-notes]\n[--no-merge-notes]\n[--verilog-data-width=val]\n[-v|--verbose]\n[-V|--version]\n[--help] [--info]\ninfile [outfile]\n", "subsections": [] }, "DESCRIPTION": { "content": "The GNU objcopy utility copies the contents of an object file to another. objcopy uses the\nGNU BFD Library to read and write the object files. It can write the destination object file\nin a format different from that of the source object file. The exact behavior of objcopy is\ncontrolled by command-line options. Note that objcopy should be able to copy a fully linked\nfile between any two formats. However, copying a relocatable object file between any two\nformats may not work as expected.\n\nobjcopy creates temporary files to do its translations and deletes them afterward. objcopy\nuses BFD to do all its translation work; it has access to all the formats described in BFD\nand thus is able to recognize most formats without being told explicitly.\n\nobjcopy can be used to generate S-records by using an output target of srec (e.g., use -O\nsrec).\n\nobjcopy can be used to generate a raw binary file by using an output target of binary (e.g.,\nuse -O binary). When objcopy generates a raw binary file, it will essentially produce a\nmemory dump of the contents of the input object file. All symbols and relocation information\nwill be discarded. The memory dump will start at the load address of the lowest section\ncopied into the output file.\n\nWhen generating an S-record or a raw binary file, it may be helpful to use -S to remove\nsections containing debugging information. In some cases -R will be useful to remove\nsections which contain information that is not needed by the binary file.\n\nNote---objcopy is not able to change the endianness of its input files. If the input format\nhas an endianness (some formats do not), objcopy can only copy the inputs into file formats\nthat have the same endianness or which have no endianness (e.g., srec). (However, see the\n--reverse-bytes option.)\n", "subsections": [] }, "OPTIONS": { "content": "infile\noutfile\nThe input and output files, respectively. If you do not specify outfile, objcopy creates\na temporary file and destructively renames the result with the name of infile.\n", "subsections": [ { "name": "-I", "content": "--input-target=bfdname\nConsider the source file's object format to be bfdname, rather than attempting to deduce\nit.\n", "flag": "-I" }, { "name": "-O", "content": "--output-target=bfdname\nWrite the output file using the object format bfdname.\n", "flag": "-O" }, { "name": "-F", "content": "--target=bfdname\nUse bfdname as the object format for both the input and the output file; i.e., simply\ntransfer data from source to destination with no translation.\n", "flag": "-F" }, { "name": "-B", "content": "--binary-architecture=bfdarch\nUseful when transforming a architecture-less input file into an object file. In this\ncase the output architecture can be set to bfdarch. This option will be ignored if the\ninput file has a known bfdarch. You can access this binary data inside a program by\nreferencing the special symbols that are created by the conversion process. These\nsymbols are called binaryobjfilestart, binaryobjfileend and binaryobjfilesize.\ne.g. you can transform a picture file into an object file and then access it in your code\nusing these symbols.\n", "flag": "-B" }, { "name": "-j", "content": "--only-section=sectionpattern\nCopy only the indicated sections from the input file to the output file. This option may\nbe given more than once. Note that using this option inappropriately may make the output\nfile unusable. Wildcard characters are accepted in sectionpattern.\n\nIf the first character of sectionpattern is the exclamation point (!) then matching\nsections will not be copied, even if earlier use of --only-section on the same command\nline would otherwise copy it. For example:\n\n--only-section=.text.* --only-section=!.text.foo\n\nwill copy all sectinos matching '.text.*' but not the section '.text.foo'.\n", "flag": "-j" }, { "name": "-R", "content": "--remove-section=sectionpattern\nRemove any section matching sectionpattern from the output file. This option may be\ngiven more than once. Note that using this option inappropriately may make the output\nfile unusable. Wildcard characters are accepted in sectionpattern. Using both the -j\nand -R options together results in undefined behaviour.\n\nIf the first character of sectionpattern is the exclamation point (!) then matching\nsections will not be removed even if an earlier use of --remove-section on the same\ncommand line would otherwise remove it. For example:\n\n--remove-section=.text.* --remove-section=!.text.foo\n\nwill remove all sections matching the pattern '.text.*', but will not remove the section\n'.text.foo'.\n\n--keep-section=sectionpattern\nWhen removing sections from the output file, keep sections that match sectionpattern.\n\n--remove-relocations=sectionpattern\nRemove non-dynamic relocations from the output file for any section matching\nsectionpattern. This option may be given more than once. Note that using this option\ninappropriately may make the output file unusable, and attempting to remove a dynamic\nrelocation section such as .rela.plt from an executable or shared library with\n--remove-relocations=.plt will not work. Wildcard characters are accepted in\nsectionpattern. For example:\n\n--remove-relocations=.text.*\n\nwill remove the relocations for all sections matching the pattern '.text.*'.\n\nIf the first character of sectionpattern is the exclamation point (!) then matching\nsections will not have their relocation removed even if an earlier use of\n--remove-relocations on the same command line would otherwise cause the relocations to be\nremoved. For example:\n\n--remove-relocations=.text.* --remove-relocations=!.text.foo\n\nwill remove all relocations for sections matching the pattern '.text.*', but will not\nremove relocations for the section '.text.foo'.\n", "flag": "-R" }, { "name": "-S", "content": "", "flag": "-S" }, { "name": "--strip-all", "content": "Do not copy relocation and symbol information from the source file. Also deletes debug\nsections.\n", "long": "--strip-all" }, { "name": "-g", "content": "", "flag": "-g" }, { "name": "--strip-debug", "content": "Do not copy debugging symbols or sections from the source file.\n", "long": "--strip-debug" }, { "name": "--strip-unneeded", "content": "Remove all symbols that are not needed for relocation processing in addition to debugging\nsymbols and sections stripped by --strip-debug.\n", "long": "--strip-unneeded" }, { "name": "-K", "content": "--keep-symbol=symbolname\nWhen stripping symbols, keep symbol symbolname even if it would normally be stripped.\nThis option may be given more than once.\n", "flag": "-K" }, { "name": "-N", "content": "--strip-symbol=symbolname\nDo not copy symbol symbolname from the source file. This option may be given more than\nonce.\n\n--strip-unneeded-symbol=symbolname\nDo not copy symbol symbolname from the source file unless it is needed by a relocation.\nThis option may be given more than once.\n", "flag": "-N" }, { "name": "-G", "content": "--keep-global-symbol=symbolname\nKeep only symbol symbolname global. Make all other symbols local to the file, so that\nthey are not visible externally. This option may be given more than once. Note: this\noption cannot be used in conjunction with the --globalize-symbol or --globalize-symbols\noptions.\n", "flag": "-G" }, { "name": "--localize-hidden", "content": "In an ELF object, mark all symbols that have hidden or internal visibility as local.\nThis option applies on top of symbol-specific localization options such as -L.\n", "long": "--localize-hidden" }, { "name": "-L", "content": "--localize-symbol=symbolname\nConvert a global or weak symbol called symbolname into a local symbol, so that it is not\nvisible externally. This option may be given more than once. Note - unique symbols are\nnot converted.\n", "flag": "-L" }, { "name": "-W", "content": "--weaken-symbol=symbolname\nMake symbol symbolname weak. This option may be given more than once.\n\n--globalize-symbol=symbolname\nGive symbol symbolname global scoping so that it is visible outside of the file in which\nit is defined. This option may be given more than once. Note: this option cannot be\nused in conjunction with the -G or --keep-global-symbol options.\n", "flag": "-W" }, { "name": "-w", "content": "", "flag": "-w" }, { "name": "--wildcard", "content": "Permit regular expressions in symbolnames used in other command line options. The\nquestion mark (?), asterisk (*), backslash (\\) and square brackets ([]) operators can be\nused anywhere in the symbol name. If the first character of the symbol name is the\nexclamation point (!) then the sense of the switch is reversed for that symbol. For\nexample:\n\n-w -W !foo -W fo*\n\nwould cause objcopy to weaken all symbols that start with \"fo\" except for the symbol\n\"foo\".\n", "long": "--wildcard" }, { "name": "-x", "content": "", "flag": "-x" }, { "name": "--discard-all", "content": "Do not copy non-global symbols from the source file.\n", "long": "--discard-all" }, { "name": "-X", "content": "", "flag": "-X" }, { "name": "--discard-locals", "content": "Do not copy compiler-generated local symbols. (These usually start with L or ..)\n", "long": "--discard-locals" }, { "name": "-b", "content": "--byte=byte\nIf interleaving has been enabled via the --interleave option then start the range of\nbytes to keep at the byteth byte. byte can be in the range from 0 to breadth-1, where\nbreadth is the value given by the --interleave option.\n", "flag": "-b" }, { "name": "-i", "content": "--interleave[=breadth]\nOnly copy a range out of every breadth bytes. (Header data is not affected). Select\nwhich byte in the range begins the copy with the --byte option. Select the width of the\nrange with the --interleave-width option.\n\nThis option is useful for creating files to program ROM. It is typically used with an\n\"srec\" output target. Note that objcopy will complain if you do not specify the --byte\noption as well.\n\nThe default interleave breadth is 4, so with --byte set to 0, objcopy would copy the\nfirst byte out of every four bytes from the input to the output.\n\n--interleave-width=width\nWhen used with the --interleave option, copy width bytes at a time. The start of the\nrange of bytes to be copied is set by the --byte option, and the extent of the range is\nset with the --interleave option.\n\nThe default value for this option is 1. The value of width plus the byte value set by\nthe --byte option must not exceed the interleave breadth set by the --interleave option.\n\nThis option can be used to create images for two 16-bit flashes interleaved in a 32-bit\nbus by passing -b 0 -i 4 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two\nobjcopy commands. If the input was '12345678' then the outputs would be '1256' and\n'3478' respectively.\n", "flag": "-i" }, { "name": "-p", "content": "", "flag": "-p" }, { "name": "--preserve-dates", "content": "Set the access and modification dates of the output file to be the same as those of the\ninput file.\n", "long": "--preserve-dates" }, { "name": "-D", "content": "", "flag": "-D" }, { "name": "--enable-deterministic-archives", "content": "Operate in deterministic mode. When copying archive members and writing the archive\nindex, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files.\n\nIf binutils was configured with --enable-deterministic-archives, then this mode is on by\ndefault. It can be disabled with the -U option, below.\n", "long": "--enable-deterministic-archives" }, { "name": "-U", "content": "", "flag": "-U" }, { "name": "--disable-deterministic-archives", "content": "Do not operate in deterministic mode. This is the inverse of the -D option, above: when\ncopying archive members and writing the archive index, use their actual UID, GID,\ntimestamp, and file mode values.\n\nThis is the default unless binutils was configured with --enable-deterministic-archives.\n", "long": "--disable-deterministic-archives" }, { "name": "--debugging", "content": "Convert debugging information, if possible. This is not the default because only certain\ndebugging formats are supported, and the conversion process can be time consuming.\n\n--gap-fill val\nFill gaps between sections with val. This operation applies to the load address (LMA) of\nthe sections. It is done by increasing the size of the section with the lower address,\nand filling in the extra space created with val.\n\n--pad-to address\nPad the output file up to the load address address. This is done by increasing the size\nof the last section. The extra space is filled in with the value specified by --gap-fill\n(default zero).\n\n--set-start val\nSet the start address (also known as the entry address) of the new file to val. Not all\nobject file formats support setting the start address.\n\n--change-start incr\n--adjust-start incr\nChange the start address (also known as the entry address) by adding incr. Not all\nobject file formats support setting the start address.\n\n--change-addresses incr\n--adjust-vma incr\nChange the VMA and LMA addresses of all sections, as well as the start address, by adding\nincr. Some object file formats do not permit section addresses to be changed\narbitrarily. Note that this does not relocate the sections; if the program expects\nsections to be loaded at a certain address, and this option is used to change the\nsections such that they are loaded at a different address, the program may fail.\n\n--change-section-address sectionpattern{=,+,-}val\n--adjust-section-vma sectionpattern{=,+,-}val\nSet or change both the VMA address and the LMA address of any section matching\nsectionpattern. If = is used, the section address is set to val. Otherwise, val is\nadded to or subtracted from the section address. See the comments under\n--change-addresses, above. If sectionpattern does not match any sections in the input\nfile, a warning will be issued, unless --no-change-warnings is used.\n\n--change-section-lma sectionpattern{=,+,-}val\nSet or change the LMA address of any sections matching sectionpattern. The LMA address\nis the address where the section will be loaded into memory at program load time.\nNormally this is the same as the VMA address, which is the address of the section at\nprogram run time, but on some systems, especially those where a program is held in ROM,\nthe two can be different. If = is used, the section address is set to val. Otherwise,\nval is added to or subtracted from the section address. See the comments under\n--change-addresses, above. If sectionpattern does not match any sections in the input\nfile, a warning will be issued, unless --no-change-warnings is used.\n\n--change-section-vma sectionpattern{=,+,-}val\nSet or change the VMA address of any section matching sectionpattern. The VMA address is\nthe address where the section will be located once the program has started executing.\nNormally this is the same as the LMA address, which is the address where the section will\nbe loaded into memory, but on some systems, especially those where a program is held in\nROM, the two can be different. If = is used, the section address is set to val.\nOtherwise, val is added to or subtracted from the section address. See the comments\nunder --change-addresses, above. If sectionpattern does not match any sections in the\ninput file, a warning will be issued, unless --no-change-warnings is used.\n", "long": "--debugging" }, { "name": "--change-warnings", "content": "", "long": "--change-warnings" }, { "name": "--adjust-warnings", "content": "If --change-section-address or --change-section-lma or --change-section-vma is used, and\nthe section pattern does not match any sections, issue a warning. This is the default.\n", "long": "--adjust-warnings" }, { "name": "--no-change-warnings", "content": "", "long": "--no-change-warnings" }, { "name": "--no-adjust-warnings", "content": "Do not issue a warning if --change-section-address or --adjust-section-lma or\n--adjust-section-vma is used, even if the section pattern does not match any sections.\n\n--set-section-flags sectionpattern=flags\nSet the flags for any sections matching sectionpattern. The flags argument is a comma\nseparated string of flag names. The recognized names are alloc, contents, load, noload,\nreadonly, code, data, rom, exclude, share, and debug. You can set the contents flag for\na section which does not have contents, but it is not meaningful to clear the contents\nflag of a section which does have contents--just remove the section instead. Not all\nflags are meaningful for all object file formats. In particular the share flag is only\nmeaningful for COFF format files and not for ELF format files.\n\n--set-section-alignment sectionpattern=align\nSet the alignment for any sections matching sectionpattern. align specifies the\nalignment in bytes and must be a power of two, i.e. 1, 2, 4, 8....\n\n--add-section sectionname=filename\nAdd a new section named sectionname while copying the file. The contents of the new\nsection are taken from the file filename. The size of the section will be the size of\nthe file. This option only works on file formats which can support sections with\narbitrary names. Note - it may be necessary to use the --set-section-flags option to set\nthe attributes of the newly created section.\n\n--dump-section sectionname=filename\nPlace the contents of section named sectionname into the file filename, overwriting any\ncontents that may have been there previously. This option is the inverse of\n--add-section. This option is similar to the --only-section option except that it does\nnot create a formatted file, it just dumps the contents as raw binary data, without\napplying any relocations. The option can be specified more than once.\n\n--update-section sectionname=filename\nReplace the existing contents of a section named sectionname with the contents of file\nfilename. The size of the section will be adjusted to the size of the file. The section\nflags for sectionname will be unchanged. For ELF format files the section to segment\nmapping will also remain unchanged, something which is not possible using\n--remove-section followed by --add-section. The option can be specified more than once.\n\nNote - it is possible to use --rename-section and --update-section to both update and\nrename a section from one command line. In this case, pass the original section name to\n--update-section, and the original and new section names to --rename-section.\n\n--add-symbol name=[section:]value[,flags]\nAdd a new symbol named name while copying the file. This option may be specified\nmultiple times. If the section is given, the symbol will be associated with and relative\nto that section, otherwise it will be an ABS symbol. Specifying an undefined section\nwill result in a fatal error. There is no check for the value, it will be taken as\nspecified. Symbol flags can be specified and not all flags will be meaningful for all\nobject file formats. By default, the symbol will be global. The special flag\n'before=othersym' will insert the new symbol in front of the specified othersym,\notherwise the symbol(s) will be added at the end of the symbol table in the order they\nappear.\n\n--rename-section oldname=newname[,flags]\nRename a section from oldname to newname, optionally changing the section's flags to\nflags in the process. This has the advantage over using a linker script to perform the\nrename in that the output stays as an object file and does not become a linked\nexecutable. This option accepts the same set of flags as the --sect-section-flags\noption.\n\nThis option is particularly helpful when the input format is binary, since this will\nalways create a section called .data. If for example, you wanted instead to create a\nsection called .rodata containing binary data you could use the following command line to\nachieve it:\n\nobjcopy -I binary -O -B \\\n--rename-section .data=.rodata,alloc,load,readonly,data,contents \\\n \n", "long": "--no-adjust-warnings" }, { "name": "--long-section-names {enable,disable,keep}", "content": "Controls the handling of long section names when processing \"COFF\" and \"PE-COFF\" object\nformats. The default behaviour, keep, is to preserve long section names if any are\npresent in the input file. The enable and disable options forcibly enable or disable the\nuse of long section names in the output object; when disable is in effect, any long\nsection names in the input object will be truncated. The enable option will only emit\nlong section names if any are present in the inputs; this is mostly the same as keep, but\nit is left undefined whether the enable option might force the creation of an empty\nstring table in the output file.\n", "long": "--long-section-names" }, { "name": "--change-leading-char", "content": "Some object file formats use special characters at the start of symbols. The most common\nsuch character is underscore, which compilers often add before every symbol. This option\ntells objcopy to change the leading character of every symbol when it converts between\nobject file formats. If the object file formats use the same leading character, this\noption has no effect. Otherwise, it will add a character, or remove a character, or\nchange a character, as appropriate.\n", "long": "--change-leading-char" }, { "name": "--remove-leading-char", "content": "If the first character of a global symbol is a special symbol leading character used by\nthe object file format, remove the character. The most common symbol leading character\nis underscore. This option will remove a leading underscore from all global symbols.\nThis can be useful if you want to link together objects of different file formats with\ndifferent conventions for symbol names. This is different from --change-leading-char\nbecause it always changes the symbol name when appropriate, regardless of the object file\nformat of the output file.\n\n--reverse-bytes=num\nReverse the bytes in a section with output contents. A section length must be evenly\ndivisible by the value given in order for the swap to be able to take place. Reversing\ntakes place before the interleaving is performed.\n\nThis option is used typically in generating ROM images for problematic target systems.\nFor example, on some target boards, the 32-bit words fetched from 8-bit ROMs are re-\nassembled in little-endian byte order regardless of the CPU byte order. Depending on the\nprogramming model, the endianness of the ROM may need to be modified.\n\nConsider a simple file with a section containing the following eight bytes: 12345678.\n\nUsing --reverse-bytes=2 for the above example, the bytes in the output file would be\nordered 21436587.\n\nUsing --reverse-bytes=4 for the above example, the bytes in the output file would be\nordered 43218765.\n\nBy using --reverse-bytes=2 for the above example, followed by --reverse-bytes=4 on the\noutput file, the bytes in the second output file would be ordered 34127856.\n\n--srec-len=ival\nMeaningful only for srec output. Set the maximum length of the Srecords being produced\nto ival. This length covers both address, data and crc fields.\n", "long": "--remove-leading-char" }, { "name": "--srec-forceS3", "content": "Meaningful only for srec output. Avoid generation of S1/S2 records, creating S3-only\nrecord format.\n\n--redefine-sym old=new\nChange the name of a symbol old, to new. This can be useful when one is trying link two\nthings together for which you have no source, and there are name collisions.\n\n--redefine-syms=filename\nApply --redefine-sym to each symbol pair \"old new\" listed in the file filename. filename\nis simply a flat file, with one symbol pair per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n", "long": "--srec-forceS3" }, { "name": "--weaken", "content": "Change all global symbols in the file to be weak. This can be useful when building an\nobject which will be linked against other objects using the -R option to the linker.\nThis option is only effective when using an object file format which supports weak\nsymbols.\n\n--keep-symbols=filename\nApply --keep-symbol option to each symbol listed in the file filename. filename is\nsimply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n\n--strip-symbols=filename\nApply --strip-symbol option to each symbol listed in the file filename. filename is\nsimply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n\n--strip-unneeded-symbols=filename\nApply --strip-unneeded-symbol option to each symbol listed in the file filename.\nfilename is simply a flat file, with one symbol name per line. Line comments may be\nintroduced by the hash character. This option may be given more than once.\n\n--keep-global-symbols=filename\nApply --keep-global-symbol option to each symbol listed in the file filename. filename\nis simply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n\n--localize-symbols=filename\nApply --localize-symbol option to each symbol listed in the file filename. filename is\nsimply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n\n--globalize-symbols=filename\nApply --globalize-symbol option to each symbol listed in the file filename. filename is\nsimply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once. Note: this option cannot\nbe used in conjunction with the -G or --keep-global-symbol options.\n\n--weaken-symbols=filename\nApply --weaken-symbol option to each symbol listed in the file filename. filename is\nsimply a flat file, with one symbol name per line. Line comments may be introduced by\nthe hash character. This option may be given more than once.\n\n--alt-machine-code=index\nIf the output architecture has alternate machine codes, use the indexth code instead of\nthe default one. This is useful in case a machine is assigned an official code and the\ntool-chain adopts the new code, but other applications still depend on the original code\nbeing used. For ELF based architectures if the index alternative does not exist then the\nvalue is treated as an absolute number to be stored in the emachine field of the ELF\nheader.\n", "long": "--weaken" }, { "name": "--writable-text", "content": "Mark the output text as writable. This option isn't meaningful for all object file\nformats.\n", "long": "--writable-text" }, { "name": "--readonly-text", "content": "Make the output text write protected. This option isn't meaningful for all object file\nformats.\n", "long": "--readonly-text" }, { "name": "--pure", "content": "Mark the output file as demand paged. This option isn't meaningful for all object file\nformats.\n", "long": "--pure" }, { "name": "--impure", "content": "Mark the output file as impure. This option isn't meaningful for all object file\nformats.\n\n--prefix-symbols=string\nPrefix all symbols in the output file with string.\n\n--prefix-sections=string\nPrefix all section names in the output file with string.\n\n--prefix-alloc-sections=string\nPrefix all the names of all allocated sections in the output file with string.\n\n--add-gnu-debuglink=path-to-file\nCreates a .gnudebuglink section which contains a reference to path-to-file and adds it\nto the output file. Note: the file at path-to-file must exist. Part of the process of\nadding the .gnudebuglink section involves embedding a checksum of the contents of the\ndebug info file into the section.\n\nIf the debug info file is built in one location but it is going to be installed at a\nlater time into a different location then do not use the path to the installed location.\nThe --add-gnu-debuglink option will fail because the installed file does not exist yet.\nInstead put the debug info file in the current directory and use the --add-gnu-debuglink\noption without any directory components, like this:\n\nobjcopy --add-gnu-debuglink=foo.debug\n\nAt debug time the debugger will attempt to look for the separate debug info file in a set\nof known locations. The exact set of these locations varies depending upon the\ndistribution being used, but it typically includes:\n\n\"* The same directory as the executable.\"\n\"* A sub-directory of the directory containing the executable\"\ncalled .debug\n\n\"* A global debug directory such as /usr/lib/debug.\"\n\nAs long as the debug info file has been installed into one of these locations before the\ndebugger is run everything should work correctly.\n", "long": "--impure" }, { "name": "--keep-section-symbils", "content": "When stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols\nspecifying section names, which would otherwise get stripped.\n", "long": "--keep-section-symbils" }, { "name": "--keep-file-symbols", "content": "When stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols\nspecifying source file names, which would otherwise get stripped.\n", "long": "--keep-file-symbols" }, { "name": "--only-keep-debug", "content": "Strip a file, removing contents of any sections that would not be stripped by\n--strip-debug and leaving the debugging sections intact. In ELF files, this preserves\nall note sections in the output.\n\nNote - the section headers of the stripped sections are preserved, including their sizes,\nbut the contents of the section are discarded. The section headers are preserved so that\nother tools can match up the debuginfo file with the real executable, even if that\nexecutable has been relocated to a different address space.\n\nThe intention is that this option will be used in conjunction with --add-gnu-debuglink to\ncreate a two part executable. One a stripped binary which will occupy less space in RAM\nand in a distribution and the second a debugging information file which is only needed if\ndebugging abilities are required. The suggested procedure to create these files is as\nfollows:\n\n1.\n\"foo\" then...\n\n1.\ncreate a file containing the debugging info.\n\n1.\nstripped executable.\n\n1.\nto add a link to the debugging info into the stripped executable.\n\nNote---the choice of \".dbg\" as an extension for the debug info file is arbitrary. Also\nthe \"--only-keep-debug\" step is optional. You could instead do this:\n\n1.\n1.\n1.\n1.\n\ni.e., the file pointed to by the --add-gnu-debuglink can be the full executable. It does\nnot have to be a file created by the --only-keep-debug switch.\n\nNote---this switch is only intended for use on fully linked files. It does not make\nsense to use it on object files where the debugging information may be incomplete.\nBesides the gnudebuglink feature currently only supports the presence of one filename\ncontaining debugging information, not multiple filenames on a one-per-object-file basis.\n", "long": "--only-keep-debug" }, { "name": "--strip-dwo", "content": "Remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections\nand all symbols intact. This option is intended for use by the compiler as part of the\n-gsplit-dwarf option, which splits debug information between the .o file and a separate\n.dwo file. The compiler generates all debug information in the same file, then uses the\n--extract-dwo option to copy the .dwo sections to the .dwo file, then the --strip-dwo\noption to remove those sections from the original .o file.\n", "long": "--strip-dwo" }, { "name": "--extract-dwo", "content": "Extract the contents of all DWARF .dwo sections. See the --strip-dwo option for more\ninformation.\n\n--file-alignment num\nSpecify the file alignment. Sections in the file will always begin at file offsets which\nare multiples of this number. This defaults to 512. [This option is specific to PE\ntargets.]\n\n--heap reserve\n--heap reserve,commit\nSpecify the number of bytes of memory to reserve (and optionally commit) to be used as\nheap for this program. [This option is specific to PE targets.]\n\n--image-base value\nUse value as the base address of your program or dll. This is the lowest memory location\nthat will be used when your program or dll is loaded. To reduce the need to relocate and\nimprove performance of your dlls, each should have a unique base address and not overlap\nany other dlls. The default is 0x400000 for executables, and 0x10000000 for dlls. [This\noption is specific to PE targets.]\n\n--section-alignment num\nSets the section alignment field in the PE header. Sections in memory will always begin\nat addresses which are a multiple of this number. Defaults to 0x1000. [This option is\nspecific to PE targets.]\n\n--stack reserve\n--stack reserve,commit\nSpecify the number of bytes of memory to reserve (and optionally commit) to be used as\nstack for this program. [This option is specific to PE targets.]\n\n--subsystem which\n--subsystem which:major\n--subsystem which:major.minor\nSpecifies the subsystem under which your program will execute. The legal values for\nwhich are \"native\", \"windows\", \"console\", \"posix\", \"efi-app\", \"efi-bsd\", \"efi-rtd\",\n\"sal-rtd\", and \"xbox\". You may optionally set the subsystem version also. Numeric\nvalues are also accepted for which. [This option is specific to PE targets.]\n", "long": "--extract-dwo" }, { "name": "--extract-symbol", "content": "Keep the file's section flags and symbols but remove all section data. Specifically, the\noption:\n\n*\n*\n*\n\nThis option is used to build a .sym file for a VxWorks kernel. It can also be a useful\nway of reducing the size of a --just-symbols linker input file.\n", "long": "--extract-symbol" }, { "name": "--compress-debug-sections", "content": "Compress DWARF debug sections using zlib with SHFCOMPRESSED from the ELF ABI. Note - if\ncompression would actually make a section larger, then it is not compressed.\n", "long": "--compress-debug-sections" }, { "name": "--compress-debug-sections=none", "content": "", "long": "--compress-debug-sections", "arg": "none" }, { "name": "--compress-debug-sections=zlib", "content": "", "long": "--compress-debug-sections", "arg": "zlib" }, { "name": "--compress-debug-sections=zlib-gnu", "content": "", "long": "--compress-debug-sections", "arg": "zlib-gnu" }, { "name": "--compress-debug-sections=zlib-gabi", "content": "For ELF files, these options control how DWARF debug sections are compressed.\n--compress-debug-sections=none is equivalent to --decompress-debug-sections.\n--compress-debug-sections=zlib and --compress-debug-sections=zlib-gabi are equivalent to\n--compress-debug-sections. --compress-debug-sections=zlib-gnu compresses DWARF debug\nsections using zlib. The debug sections are renamed to begin with .zdebug instead of\n.debug. Note - if compression would actually make a section larger, then it is not\ncompressed nor renamed.\n", "long": "--compress-debug-sections", "arg": "zlib-gabi" }, { "name": "--decompress-debug-sections", "content": "Decompress DWARF debug sections using zlib. The original section names of the compressed\nsections are restored.\n", "long": "--decompress-debug-sections" }, { "name": "--elf-stt-common=yes", "content": "", "long": "--elf-stt-common", "arg": "yes" }, { "name": "--elf-stt-common=no", "content": "For ELF files, these options control whether common symbols should be converted to the\n\"STTCOMMON\" or \"STTOBJECT\" type. --elf-stt-common=yes converts common symbol type to\n\"STTCOMMON\". --elf-stt-common=no converts common symbol type to \"STTOBJECT\".\n", "long": "--elf-stt-common", "arg": "no" }, { "name": "--merge-notes", "content": "", "long": "--merge-notes" }, { "name": "--no-merge-notes", "content": "For ELF files, attempt (or do not attempt) to reduce the size of any SHTNOTE type\nsections by removing duplicate notes.\n", "long": "--no-merge-notes" }, { "name": "-V", "content": "", "flag": "-V" }, { "name": "--version", "content": "Show the version number of objcopy.\n\n--verilog-data-width=bytes\nFor Verilog output, this options controls the number of bytes converted for each output\ndata element. The input target controls the endianness of the conversion.\n", "long": "--version" }, { "name": "-v", "content": "", "flag": "-v" }, { "name": "--verbose", "content": "Verbose output: list all object files modified. In the case of archives, objcopy -V\nlists all members of the archive.\n", "long": "--verbose" }, { "name": "--help", "content": "Show a summary of the options to objcopy.\n", "long": "--help" }, { "name": "--info", "content": "Display a list showing all architectures and object formats available.\n\n@file\nRead command-line options from file. The options read are inserted in place of the\noriginal @file option. If file does not exist, or cannot be read, then the option will\nbe treated literally, and not removed.\n\nOptions in file are separated by whitespace. A whitespace character may be included in\nan option by surrounding the entire option in either single or double quotes. Any\ncharacter (including a backslash) may be included by prefixing the character to be\nincluded with a backslash. The file may itself contain additional @file options; any\nsuch options will be processed recursively.\n", "long": "--info" } ] }, "SEE ALSO": { "content": "ld(1), objdump(1), and the Info entries for binutils.\n", "subsections": [] }, "COPYRIGHT": { "content": "Copyright (c) 1991-2022 Free Software Foundation, Inc.\n\nPermission is granted to copy, distribute and/or modify this document under the terms of the\nGNU Free Documentation License, Version 1.3 or any later version published by the Free\nSoftware Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-\nCover Texts. A copy of the license is included in the section entitled \"GNU Free\nDocumentation License\".\n\n\n\nbinutils-2.38 2025-12-03 OBJCOPY(1)", "subsections": [] } }, "summary": "objcopy - copy and translate object files", "flags": [ { "flag": "-I", "long": null, "arg": null, "description": "--input-target=bfdname Consider the source file's object format to be bfdname, rather than attempting to deduce it." }, { "flag": "-O", "long": null, "arg": null, "description": "--output-target=bfdname Write the output file using the object format bfdname." }, { "flag": "-F", "long": null, "arg": null, "description": "--target=bfdname Use bfdname as the object format for both the input and the output file; i.e., simply transfer data from source to destination with no translation." }, { "flag": "-B", "long": null, "arg": null, "description": "--binary-architecture=bfdarch Useful when transforming a architecture-less input file into an object file. In this case the output architecture can be set to bfdarch. This option will be ignored if the input file has a known bfdarch. You can access this binary data inside a program by referencing the special symbols that are created by the conversion process. These symbols are called binaryobjfilestart, binaryobjfileend and binaryobjfilesize. e.g. you can transform a picture file into an object file and then access it in your code using these symbols." }, { "flag": "-j", "long": null, "arg": null, "description": "--only-section=sectionpattern Copy only the indicated sections from the input file to the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Wildcard characters are accepted in sectionpattern. If the first character of sectionpattern is the exclamation point (!) then matching sections will not be copied, even if earlier use of --only-section on the same command line would otherwise copy it. For example: --only-section=.text.* --only-section=!.text.foo will copy all sectinos matching '.text.*' but not the section '.text.foo'." }, { "flag": "-R", "long": null, "arg": null, "description": "--remove-section=sectionpattern Remove any section matching sectionpattern from the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable. Wildcard characters are accepted in sectionpattern. Using both the -j and -R options together results in undefined behaviour. If the first character of sectionpattern is the exclamation point (!) then matching sections will not be removed even if an earlier use of --remove-section on the same command line would otherwise remove it. For example: --remove-section=.text.* --remove-section=!.text.foo will remove all sections matching the pattern '.text.*', but will not remove the section '.text.foo'. --keep-section=sectionpattern When removing sections from the output file, keep sections that match sectionpattern. --remove-relocations=sectionpattern Remove non-dynamic relocations from the output file for any section matching sectionpattern. This option may be given more than once. Note that using this option inappropriately may make the output file unusable, and attempting to remove a dynamic relocation section such as .rela.plt from an executable or shared library with --remove-relocations=.plt will not work. Wildcard characters are accepted in sectionpattern. For example: --remove-relocations=.text.* will remove the relocations for all sections matching the pattern '.text.*'. If the first character of sectionpattern is the exclamation point (!) then matching sections will not have their relocation removed even if an earlier use of --remove-relocations on the same command line would otherwise cause the relocations to be removed. For example: --remove-relocations=.text.* --remove-relocations=!.text.foo will remove all relocations for sections matching the pattern '.text.*', but will not remove relocations for the section '.text.foo'." }, { "flag": "-S", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--strip-all", "arg": null, "description": "Do not copy relocation and symbol information from the source file. Also deletes debug sections." }, { "flag": "-g", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--strip-debug", "arg": null, "description": "Do not copy debugging symbols or sections from the source file." }, { "flag": "", "long": "--strip-unneeded", "arg": null, "description": "Remove all symbols that are not needed for relocation processing in addition to debugging symbols and sections stripped by --strip-debug." }, { "flag": "-K", "long": null, "arg": null, "description": "--keep-symbol=symbolname When stripping symbols, keep symbol symbolname even if it would normally be stripped. This option may be given more than once." }, { "flag": "-N", "long": null, "arg": null, "description": "--strip-symbol=symbolname Do not copy symbol symbolname from the source file. This option may be given more than once. --strip-unneeded-symbol=symbolname Do not copy symbol symbolname from the source file unless it is needed by a relocation. This option may be given more than once." }, { "flag": "-G", "long": null, "arg": null, "description": "--keep-global-symbol=symbolname Keep only symbol symbolname global. Make all other symbols local to the file, so that they are not visible externally. This option may be given more than once. Note: this option cannot be used in conjunction with the --globalize-symbol or --globalize-symbols options." }, { "flag": "", "long": "--localize-hidden", "arg": null, "description": "In an ELF object, mark all symbols that have hidden or internal visibility as local. This option applies on top of symbol-specific localization options such as -L." }, { "flag": "-L", "long": null, "arg": null, "description": "--localize-symbol=symbolname Convert a global or weak symbol called symbolname into a local symbol, so that it is not visible externally. This option may be given more than once. Note - unique symbols are not converted." }, { "flag": "-W", "long": null, "arg": null, "description": "--weaken-symbol=symbolname Make symbol symbolname weak. This option may be given more than once. --globalize-symbol=symbolname Give symbol symbolname global scoping so that it is visible outside of the file in which it is defined. This option may be given more than once. Note: this option cannot be used in conjunction with the -G or --keep-global-symbol options." }, { "flag": "-w", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--wildcard", "arg": null, "description": "Permit regular expressions in symbolnames used in other command line options. The question mark (?), asterisk (*), backslash (\\) and square brackets ([]) operators can be used anywhere in the symbol name. If the first character of the symbol name is the exclamation point (!) then the sense of the switch is reversed for that symbol. For example: -w -W !foo -W fo* would cause objcopy to weaken all symbols that start with \"fo\" except for the symbol \"foo\"." }, { "flag": "-x", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--discard-all", "arg": null, "description": "Do not copy non-global symbols from the source file." }, { "flag": "-X", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--discard-locals", "arg": null, "description": "Do not copy compiler-generated local symbols. (These usually start with L or ..)" }, { "flag": "-b", "long": null, "arg": null, "description": "--byte=byte If interleaving has been enabled via the --interleave option then start the range of bytes to keep at the byteth byte. byte can be in the range from 0 to breadth-1, where breadth is the value given by the --interleave option." }, { "flag": "-i", "long": null, "arg": null, "description": "--interleave[=breadth] Only copy a range out of every breadth bytes. (Header data is not affected). Select which byte in the range begins the copy with the --byte option. Select the width of the range with the --interleave-width option. This option is useful for creating files to program ROM. It is typically used with an \"srec\" output target. Note that objcopy will complain if you do not specify the --byte option as well. The default interleave breadth is 4, so with --byte set to 0, objcopy would copy the first byte out of every four bytes from the input to the output. --interleave-width=width When used with the --interleave option, copy width bytes at a time. The start of the range of bytes to be copied is set by the --byte option, and the extent of the range is set with the --interleave option. The default value for this option is 1. The value of width plus the byte value set by the --byte option must not exceed the interleave breadth set by the --interleave option. This option can be used to create images for two 16-bit flashes interleaved in a 32-bit bus by passing -b 0 -i 4 --interleave-width=2 and -b 2 -i 4 --interleave-width=2 to two objcopy commands. If the input was '12345678' then the outputs would be '1256' and '3478' respectively." }, { "flag": "-p", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--preserve-dates", "arg": null, "description": "Set the access and modification dates of the output file to be the same as those of the input file." }, { "flag": "-D", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--enable-deterministic-archives", "arg": null, "description": "Operate in deterministic mode. When copying archive members and writing the archive index, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files. If binutils was configured with --enable-deterministic-archives, then this mode is on by default. It can be disabled with the -U option, below." }, { "flag": "-U", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--disable-deterministic-archives", "arg": null, "description": "Do not operate in deterministic mode. This is the inverse of the -D option, above: when copying archive members and writing the archive index, use their actual UID, GID, timestamp, and file mode values. This is the default unless binutils was configured with --enable-deterministic-archives." }, { "flag": "", "long": "--debugging", "arg": null, "description": "Convert debugging information, if possible. This is not the default because only certain debugging formats are supported, and the conversion process can be time consuming. --gap-fill val Fill gaps between sections with val. This operation applies to the load address (LMA) of the sections. It is done by increasing the size of the section with the lower address, and filling in the extra space created with val. --pad-to address Pad the output file up to the load address address. This is done by increasing the size of the last section. The extra space is filled in with the value specified by --gap-fill (default zero). --set-start val Set the start address (also known as the entry address) of the new file to val. Not all object file formats support setting the start address. --change-start incr --adjust-start incr Change the start address (also known as the entry address) by adding incr. Not all object file formats support setting the start address. --change-addresses incr --adjust-vma incr Change the VMA and LMA addresses of all sections, as well as the start address, by adding incr. Some object file formats do not permit section addresses to be changed arbitrarily. Note that this does not relocate the sections; if the program expects sections to be loaded at a certain address, and this option is used to change the sections such that they are loaded at a different address, the program may fail. --change-section-address sectionpattern{=,+,-}val --adjust-section-vma sectionpattern{=,+,-}val Set or change both the VMA address and the LMA address of any section matching sectionpattern. If = is used, the section address is set to val. Otherwise, val is added to or subtracted from the section address. See the comments under --change-addresses, above. If sectionpattern does not match any sections in the input file, a warning will be issued, unless --no-change-warnings is used. --change-section-lma sectionpattern{=,+,-}val Set or change the LMA address of any sections matching sectionpattern. The LMA address is the address where the section will be loaded into memory at program load time. Normally this is the same as the VMA address, which is the address of the section at program run time, but on some systems, especially those where a program is held in ROM, the two can be different. If = is used, the section address is set to val. Otherwise, val is added to or subtracted from the section address. See the comments under --change-addresses, above. If sectionpattern does not match any sections in the input file, a warning will be issued, unless --no-change-warnings is used. --change-section-vma sectionpattern{=,+,-}val Set or change the VMA address of any section matching sectionpattern. The VMA address is the address where the section will be located once the program has started executing. Normally this is the same as the LMA address, which is the address where the section will be loaded into memory, but on some systems, especially those where a program is held in ROM, the two can be different. If = is used, the section address is set to val. Otherwise, val is added to or subtracted from the section address. See the comments under --change-addresses, above. If sectionpattern does not match any sections in the input file, a warning will be issued, unless --no-change-warnings is used." }, { "flag": "", "long": "--change-warnings", "arg": null, "description": "" }, { "flag": "", "long": "--adjust-warnings", "arg": null, "description": "If --change-section-address or --change-section-lma or --change-section-vma is used, and the section pattern does not match any sections, issue a warning. This is the default." }, { "flag": "", "long": "--no-change-warnings", "arg": null, "description": "" }, { "flag": "", "long": "--no-adjust-warnings", "arg": null, "description": "Do not issue a warning if --change-section-address or --adjust-section-lma or --adjust-section-vma is used, even if the section pattern does not match any sections. --set-section-flags sectionpattern=flags Set the flags for any sections matching sectionpattern. The flags argument is a comma separated string of flag names. The recognized names are alloc, contents, load, noload, readonly, code, data, rom, exclude, share, and debug. You can set the contents flag for a section which does not have contents, but it is not meaningful to clear the contents flag of a section which does have contents--just remove the section instead. Not all flags are meaningful for all object file formats. In particular the share flag is only meaningful for COFF format files and not for ELF format files. --set-section-alignment sectionpattern=align Set the alignment for any sections matching sectionpattern. align specifies the alignment in bytes and must be a power of two, i.e. 1, 2, 4, 8.... --add-section sectionname=filename Add a new section named sectionname while copying the file. The contents of the new section are taken from the file filename. The size of the section will be the size of the file. This option only works on file formats which can support sections with arbitrary names. Note - it may be necessary to use the --set-section-flags option to set the attributes of the newly created section. --dump-section sectionname=filename Place the contents of section named sectionname into the file filename, overwriting any contents that may have been there previously. This option is the inverse of --add-section. This option is similar to the --only-section option except that it does not create a formatted file, it just dumps the contents as raw binary data, without applying any relocations. The option can be specified more than once. --update-section sectionname=filename Replace the existing contents of a section named sectionname with the contents of file filename. The size of the section will be adjusted to the size of the file. The section flags for sectionname will be unchanged. For ELF format files the section to segment mapping will also remain unchanged, something which is not possible using --remove-section followed by --add-section. The option can be specified more than once. Note - it is possible to use --rename-section and --update-section to both update and rename a section from one command line. In this case, pass the original section name to --update-section, and the original and new section names to --rename-section. --add-symbol name=[section:]value[,flags] Add a new symbol named name while copying the file. This option may be specified multiple times. If the section is given, the symbol will be associated with and relative to that section, otherwise it will be an ABS symbol. Specifying an undefined section will result in a fatal error. There is no check for the value, it will be taken as specified. Symbol flags can be specified and not all flags will be meaningful for all object file formats. By default, the symbol will be global. The special flag 'before=othersym' will insert the new symbol in front of the specified othersym, otherwise the symbol(s) will be added at the end of the symbol table in the order they appear. --rename-section oldname=newname[,flags] Rename a section from oldname to newname, optionally changing the section's flags to flags in the process. This has the advantage over using a linker script to perform the rename in that the output stays as an object file and does not become a linked executable. This option accepts the same set of flags as the --sect-section-flags option. This option is particularly helpful when the input format is binary, since this will always create a section called .data. If for example, you wanted instead to create a section called .rodata containing binary data you could use the following command line to achieve it: objcopy -I binary -O -B \\ --rename-section .data=.rodata,alloc,load,readonly,data,contents \\ " }, { "flag": "", "long": "--long-section-names", "arg": null, "description": "Controls the handling of long section names when processing \"COFF\" and \"PE-COFF\" object formats. The default behaviour, keep, is to preserve long section names if any are present in the input file. The enable and disable options forcibly enable or disable the use of long section names in the output object; when disable is in effect, any long section names in the input object will be truncated. The enable option will only emit long section names if any are present in the inputs; this is mostly the same as keep, but it is left undefined whether the enable option might force the creation of an empty string table in the output file." }, { "flag": "", "long": "--change-leading-char", "arg": null, "description": "Some object file formats use special characters at the start of symbols. The most common such character is underscore, which compilers often add before every symbol. This option tells objcopy to change the leading character of every symbol when it converts between object file formats. If the object file formats use the same leading character, this option has no effect. Otherwise, it will add a character, or remove a character, or change a character, as appropriate." }, { "flag": "", "long": "--remove-leading-char", "arg": null, "description": "If the first character of a global symbol is a special symbol leading character used by the object file format, remove the character. The most common symbol leading character is underscore. This option will remove a leading underscore from all global symbols. This can be useful if you want to link together objects of different file formats with different conventions for symbol names. This is different from --change-leading-char because it always changes the symbol name when appropriate, regardless of the object file format of the output file. --reverse-bytes=num Reverse the bytes in a section with output contents. A section length must be evenly divisible by the value given in order for the swap to be able to take place. Reversing takes place before the interleaving is performed. This option is used typically in generating ROM images for problematic target systems. For example, on some target boards, the 32-bit words fetched from 8-bit ROMs are re- assembled in little-endian byte order regardless of the CPU byte order. Depending on the programming model, the endianness of the ROM may need to be modified. Consider a simple file with a section containing the following eight bytes: 12345678. Using --reverse-bytes=2 for the above example, the bytes in the output file would be ordered 21436587. Using --reverse-bytes=4 for the above example, the bytes in the output file would be ordered 43218765. By using --reverse-bytes=2 for the above example, followed by --reverse-bytes=4 on the output file, the bytes in the second output file would be ordered 34127856. --srec-len=ival Meaningful only for srec output. Set the maximum length of the Srecords being produced to ival. This length covers both address, data and crc fields." }, { "flag": "", "long": "--srec-forceS3", "arg": null, "description": "Meaningful only for srec output. Avoid generation of S1/S2 records, creating S3-only record format. --redefine-sym old=new Change the name of a symbol old, to new. This can be useful when one is trying link two things together for which you have no source, and there are name collisions. --redefine-syms=filename Apply --redefine-sym to each symbol pair \"old new\" listed in the file filename. filename is simply a flat file, with one symbol pair per line. Line comments may be introduced by the hash character. This option may be given more than once." }, { "flag": "", "long": "--weaken", "arg": null, "description": "Change all global symbols in the file to be weak. This can be useful when building an object which will be linked against other objects using the -R option to the linker. This option is only effective when using an object file format which supports weak symbols. --keep-symbols=filename Apply --keep-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --strip-symbols=filename Apply --strip-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --strip-unneeded-symbols=filename Apply --strip-unneeded-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --keep-global-symbols=filename Apply --keep-global-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --localize-symbols=filename Apply --localize-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --globalize-symbols=filename Apply --globalize-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. Note: this option cannot be used in conjunction with the -G or --keep-global-symbol options. --weaken-symbols=filename Apply --weaken-symbol option to each symbol listed in the file filename. filename is simply a flat file, with one symbol name per line. Line comments may be introduced by the hash character. This option may be given more than once. --alt-machine-code=index If the output architecture has alternate machine codes, use the indexth code instead of the default one. This is useful in case a machine is assigned an official code and the tool-chain adopts the new code, but other applications still depend on the original code being used. For ELF based architectures if the index alternative does not exist then the value is treated as an absolute number to be stored in the emachine field of the ELF header." }, { "flag": "", "long": "--writable-text", "arg": null, "description": "Mark the output text as writable. This option isn't meaningful for all object file formats." }, { "flag": "", "long": "--readonly-text", "arg": null, "description": "Make the output text write protected. This option isn't meaningful for all object file formats." }, { "flag": "", "long": "--pure", "arg": null, "description": "Mark the output file as demand paged. This option isn't meaningful for all object file formats." }, { "flag": "", "long": "--impure", "arg": null, "description": "Mark the output file as impure. This option isn't meaningful for all object file formats. --prefix-symbols=string Prefix all symbols in the output file with string. --prefix-sections=string Prefix all section names in the output file with string. --prefix-alloc-sections=string Prefix all the names of all allocated sections in the output file with string. --add-gnu-debuglink=path-to-file Creates a .gnudebuglink section which contains a reference to path-to-file and adds it to the output file. Note: the file at path-to-file must exist. Part of the process of adding the .gnudebuglink section involves embedding a checksum of the contents of the debug info file into the section. If the debug info file is built in one location but it is going to be installed at a later time into a different location then do not use the path to the installed location. The --add-gnu-debuglink option will fail because the installed file does not exist yet. Instead put the debug info file in the current directory and use the --add-gnu-debuglink option without any directory components, like this: objcopy --add-gnu-debuglink=foo.debug At debug time the debugger will attempt to look for the separate debug info file in a set of known locations. The exact set of these locations varies depending upon the distribution being used, but it typically includes: \"* The same directory as the executable.\" \"* A sub-directory of the directory containing the executable\" called .debug \"* A global debug directory such as /usr/lib/debug.\" As long as the debug info file has been installed into one of these locations before the debugger is run everything should work correctly." }, { "flag": "", "long": "--keep-section-symbils", "arg": null, "description": "When stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols specifying section names, which would otherwise get stripped." }, { "flag": "", "long": "--keep-file-symbols", "arg": null, "description": "When stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols specifying source file names, which would otherwise get stripped." }, { "flag": "", "long": "--only-keep-debug", "arg": null, "description": "Strip a file, removing contents of any sections that would not be stripped by --strip-debug and leaving the debugging sections intact. In ELF files, this preserves all note sections in the output. Note - the section headers of the stripped sections are preserved, including their sizes, but the contents of the section are discarded. The section headers are preserved so that other tools can match up the debuginfo file with the real executable, even if that executable has been relocated to a different address space. The intention is that this option will be used in conjunction with --add-gnu-debuglink to create a two part executable. One a stripped binary which will occupy less space in RAM and in a distribution and the second a debugging information file which is only needed if debugging abilities are required. The suggested procedure to create these files is as follows: 1. \"foo\" then... 1. create a file containing the debugging info. 1. stripped executable. 1. to add a link to the debugging info into the stripped executable. Note---the choice of \".dbg\" as an extension for the debug info file is arbitrary. Also the \"--only-keep-debug\" step is optional. You could instead do this: 1. 1. 1. 1. i.e., the file pointed to by the --add-gnu-debuglink can be the full executable. It does not have to be a file created by the --only-keep-debug switch. Note---this switch is only intended for use on fully linked files. It does not make sense to use it on object files where the debugging information may be incomplete. Besides the gnudebuglink feature currently only supports the presence of one filename containing debugging information, not multiple filenames on a one-per-object-file basis." }, { "flag": "", "long": "--strip-dwo", "arg": null, "description": "Remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections and all symbols intact. This option is intended for use by the compiler as part of the -gsplit-dwarf option, which splits debug information between the .o file and a separate .dwo file. The compiler generates all debug information in the same file, then uses the --extract-dwo option to copy the .dwo sections to the .dwo file, then the --strip-dwo option to remove those sections from the original .o file." }, { "flag": "", "long": "--extract-dwo", "arg": null, "description": "Extract the contents of all DWARF .dwo sections. See the --strip-dwo option for more information. --file-alignment num Specify the file alignment. Sections in the file will always begin at file offsets which are multiples of this number. This defaults to 512. [This option is specific to PE targets.] --heap reserve --heap reserve,commit Specify the number of bytes of memory to reserve (and optionally commit) to be used as heap for this program. [This option is specific to PE targets.] --image-base value Use value as the base address of your program or dll. This is the lowest memory location that will be used when your program or dll is loaded. To reduce the need to relocate and improve performance of your dlls, each should have a unique base address and not overlap any other dlls. The default is 0x400000 for executables, and 0x10000000 for dlls. [This option is specific to PE targets.] --section-alignment num Sets the section alignment field in the PE header. Sections in memory will always begin at addresses which are a multiple of this number. Defaults to 0x1000. [This option is specific to PE targets.] --stack reserve --stack reserve,commit Specify the number of bytes of memory to reserve (and optionally commit) to be used as stack for this program. [This option is specific to PE targets.] --subsystem which --subsystem which:major --subsystem which:major.minor Specifies the subsystem under which your program will execute. The legal values for which are \"native\", \"windows\", \"console\", \"posix\", \"efi-app\", \"efi-bsd\", \"efi-rtd\", \"sal-rtd\", and \"xbox\". You may optionally set the subsystem version also. Numeric values are also accepted for which. [This option is specific to PE targets.]" }, { "flag": "", "long": "--extract-symbol", "arg": null, "description": "Keep the file's section flags and symbols but remove all section data. Specifically, the option: * * * This option is used to build a .sym file for a VxWorks kernel. It can also be a useful way of reducing the size of a --just-symbols linker input file." }, { "flag": "", "long": "--compress-debug-sections", "arg": null, "description": "Compress DWARF debug sections using zlib with SHFCOMPRESSED from the ELF ABI. Note - if compression would actually make a section larger, then it is not compressed." }, { "flag": "", "long": "--compress-debug-sections", "arg": "none", "description": "" }, { "flag": "", "long": "--compress-debug-sections", "arg": "zlib", "description": "" }, { "flag": "", "long": "--compress-debug-sections", "arg": "zlib-gnu", "description": "" }, { "flag": "", "long": "--compress-debug-sections", "arg": "zlib-gabi", "description": "For ELF files, these options control how DWARF debug sections are compressed. --compress-debug-sections=none is equivalent to --decompress-debug-sections. --compress-debug-sections=zlib and --compress-debug-sections=zlib-gabi are equivalent to --compress-debug-sections. --compress-debug-sections=zlib-gnu compresses DWARF debug sections using zlib. The debug sections are renamed to begin with .zdebug instead of .debug. Note - if compression would actually make a section larger, then it is not compressed nor renamed." }, { "flag": "", "long": "--decompress-debug-sections", "arg": null, "description": "Decompress DWARF debug sections using zlib. The original section names of the compressed sections are restored." }, { "flag": "", "long": "--elf-stt-common", "arg": "yes", "description": "" }, { "flag": "", "long": "--elf-stt-common", "arg": "no", "description": "For ELF files, these options control whether common symbols should be converted to the \"STTCOMMON\" or \"STTOBJECT\" type. --elf-stt-common=yes converts common symbol type to \"STTCOMMON\". --elf-stt-common=no converts common symbol type to \"STTOBJECT\"." }, { "flag": "", "long": "--merge-notes", "arg": null, "description": "" }, { "flag": "", "long": "--no-merge-notes", "arg": null, "description": "For ELF files, attempt (or do not attempt) to reduce the size of any SHTNOTE type sections by removing duplicate notes." }, { "flag": "-V", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--version", "arg": null, "description": "Show the version number of objcopy. --verilog-data-width=bytes For Verilog output, this options controls the number of bytes converted for each output data element. The input target controls the endianness of the conversion." }, { "flag": "-v", "long": null, "arg": null, "description": "" }, { "flag": "", "long": "--verbose", "arg": null, "description": "Verbose output: list all object files modified. In the case of archives, objcopy -V lists all members of the archive." }, { "flag": "", "long": "--help", "arg": null, "description": "Show a summary of the options to objcopy." }, { "flag": "", "long": "--info", "arg": null, "description": "Display a list showing all architectures and object formats available. @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." } ], "examples": [], "see_also": [ { "name": "ld", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ld/1/json" }, { "name": "objdump", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/objdump/1/json" } ] }