redhat man page for genksyms

GENKSYMS(8)						       Linux Module Support						       GENKSYMS(8)

NAME
       genksyms - generate symbol version information

SYNOPSIS
       genksyms [-wq] [-dD] [-V] [-k version] [-p string] [output directory]

DESCRIPTION
       Genksyms reads (on standard input) the output from "gcc -E source.c" and generates a file containing version information.

       Depending  on the output format indicated by the -k option, the output will either be written to a .ver file in the named output directory,
       or to the standard output.

       Genksyms normally looks	for  explicit  symbol  table  definitions  in  the  source  file.   All  definitions  and  declarations  of  type-
       def, struct, union and enum  will  be  saved for later expansion.  Every global symbol will also be saved, together with pointers that will
       enable a full expansion later on.

       When a symbol table is found in the source, the symbol will be expanded to its full definition, where all structs, unions, enums and  type-
       defs  will  be  expanded  down to their basic part, recursively.  This final string will then be used as input to a CRC algorithm that will
       give an integer that will change as soon as any of the included definitions changes, for this symbol.

       The version information in the kernel normally looks like: symbol_R12345678, where 12345678 is the hexadecimal representation of the CRC.

OPTIONS
       -d, --debug
	      Output debugging information; repeating this option increases the verbosity.  Debug level 1 generates moderate information about the
	      actions being taken; debug level 2 enables parser recognition output; debug level 3 enables lexical analysis output.

       -D, --dump
	      Dump expanded symbol definitions to stderr.  For debugging use only.

       -h, --help
	      Display a summary of options and immediately exit.

       -k version, --kernel version
	      Select  the version of the kernel for which to generate output.  Omitting this option assumes a version below 2.1.0.  Versions below
	      2.1.18 use checksum version 1, and produce their output in the directory given on the command line.  Versions 2.1.18 and	above  use
	      checksum version 2 and produce their output on stdout.

       -p string, --prefix string
	      Prepend  the given string to the CRCs generated for all symbols.	This is intended for use with, e.g., SMP kernels, wherein the mod-
	      ules are not compatible at a level below that described by the data types.  This is primarily caused by inline  function	expansions
	      in the module code itself.

       -q, --quiet
	      Quiet warnings, i.e. reverse the -w option.

       -V, --version
	      Display the version of genksyms.

       -w, --warnings
	      Enable warnings due to unrecognized syntax and declared but undefined structures.  These warnings are normally suppressed.

SEE ALSO
       insmod(8), modprobe(8)

BUGS
       The -h option is broken; --help is fine.
       genksyms  [-V | --version]  should  display  version information and then exit immediately.  Instead, it prints the version information and
       behaves as if no options were given.

HISTORY
       This versioning concept is a result from discussions, not at least on the KERNEL-channel, with a lot of people.

       The genksyms utility was created in 1994 by Bjorn Ekwall <bj0rn@blox.se> being mostly inspired by Jacques  Gelinas  <jack@solucorp.ca>  and
       Jeremy Fitzhardinge <jeremy@suite.sw.oz.au>

       It was rewritten in 1996 by Richard Henderson to use a proper lexer and parser.

Linux								 January 30, 2002						       GENKSYMS(8)