.\" $NetBSD: crunchgen.1,v 1.15 2002/01/25 12:05:00 ragge Exp $ .\" .\" Copyright (c) 1994 University of Maryland .\" All Rights Reserved. .\" .\" Permission to use, copy, modify, distribute, and sell this software and its .\" documentation for any purpose is hereby granted without fee, provided that .\" the above copyright notice appear in all copies and that both that .\" copyright notice and this permission notice appear in supporting .\" documentation, and that the name of U.M. not be used in advertising or .\" publicity pertaining to distribution of the software without specific, .\" written prior permission. U.M. makes no representations about the .\" suitability of this software for any purpose. It is provided "as is" .\" without express or implied warranty. .\" .\" U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M. .\" BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR .\" IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .\" Author: James da Silva, Systems Design and Analysis Group .\" Computer Science Department .\" University of Maryland at College Park .\" .Dd June 14, 1994 .Dt CRUNCHGEN 1 .Os .Sh NAME .Nm crunchgen .Nd generates build environment for a crunched binary .Sh SYNOPSIS .Nm "" .Op Fl fq .Bk -words .Op Fl m Ar makefile-name .Ek .Bk -words .Op Fl c Ar c-file-name .Ek .Bk -words .Op Fl e Ar exec-file-name .Ek .Bk -words .Op Fl D Ar src-root .Ek .Bk -words .Op Fl L Ar lib-dir .Ek .Bk -words .Op Ar conf-file .Ek .Sh DESCRIPTION A crunched binary is a program made up of many other programs linked together into a single executable. The crunched binary main() function determines which component program to run by the contents of argv[0]. The main reason to crunch programs together is for fitting as many programs as possible onto an installation or system recovery floppy. .Pp .Nm reads in the specifications in .Ar conf-file for a crunched binary, and generates a Makefile and accompanying top-level C source file that when built create the crunched executable file from the component programs. For each component program, .Nm can optionally attempt to determine the object (.o) files that make up the program from its source directory Makefile. This information is cached between runs. .Nm uses the companion program .Em crunchide to eliminate link-time conflicts between the component programs by hiding all unnecessary symbols. .Pp After .Nm is run, the crunched binary can be built by running ``make -f .mk''. The component programs' object files must already be built. A ``objs'' target, included in the output makefile, will run make in each component program's source dir to build the object files for the user. This is not done automatically since in release engineering circumstances it is generally not desireable to be modifying objects in other directories. .Pp The options are as follows: .Bl -tag -width indent .It Fl c Ar c-file-name Set output C file name to .Ar c-file-name . The default name is ``.c''. .It Fl e Ar exec-file-name Set crunched binary executable file name to .Ar exec-file-name . The default name is ``''. .It Fl d Ar build-options Set the DBG variable in the generated makefile to .Ar build-options . The default flags are -Os. .It Fl f Flush cache. Forces the recalculation of cached parameters. .It Fl m Ar makefile-name Set output Makefile name to .Ar makefile-name . The default name is ``.mk''. .It Fl o Use existing object files. Rather than rebuilding object files via reach-over makefiles, instead search for and use existing object files. .It Fl q Quiet operation. Status messages are suppressed. .It Fl D Ar src-root Assume that relative source directory specifications begin with .Ar src-root . .It Fl L Ar lib-dir Try to obtain libraries from .Ar lib-dir . .El .Sh CRUNCHGEN CONFIGURATION FILE COMMANDS .Nm reads specifications from the .Ar conf-file that describe the components of the crunched binary. In its simplest use, the component program names are merely listed along with the top-level source directories in which their sources can be found. .Nm then calculates (via the source makefiles) and caches the list of object files and their locations. For more specialized situations, the user can specify by hand all the parameters that .Nm needs. .Pp The .Ar conf-file commands are as follows: .Bl -tag -width indent .It Nm srcdirs Ar dirname ... A list of source trees in which the source directories of the component programs can be found. These dirs are searched using the .Bx ``//'' convention. Multiple .Em srcdirs lines can be specified. The directories are searched in the order they are given. .It Nm progs Ar progname ... A list of programs that make up the crunched binary. Multiple .Em progs lines can be specified. .It Nm libs Ar libspec ... A list of library specifications to be included in the crunched binary link. Multiple .Em libs lines can be specified. .It Nm ln Ar progname linkname Causes the crunched binary to invoke .Ar progname whenever .Ar linkname appears in argv[0]. This allows programs that change their behavior when run under different names to operate correctly. .El .Pp To handle specialized situations, such as when the source is not available or not built via a conventional Makefile, the following .Em special commands can be used to set .Nm parameters for a component program. .Bl -tag -width indent .It Nm special Ar progname Nm keepsymbols Ar symbols ... Don't hide the specified symbols for .Ar progname . Normally all externally visible symbols for a program is hidden to avoid interference. .It Nm special Ar progname Nm srcdir Ar pathname Set the source directory for .Ar progname . This is normally calculated by searching the specified .Em srcdirs for a directory named .Ar progname . .It Nm special Ar progname Nm objdir Ar pathname Set the obj directory for .Ar progname . This is normally calculated by looking for a directory named .Dq Pa obj under the .Ar srcdir , and if that is not found, the .Ar srcdir itself becomes the .Ar objdir . .br .Nm Note : This option only takes effect if the -o option to use existing object files is also specified. .It Nm special Ar progname Nm objs Ar object-file-name ... Set the list of object files for program .Ar progname . This is normally calculated by constructing a temporary makefile that includes .Dq Nm srcdir / Pa Makefile and outputs the value of $(OBJS). .It Nm special Ar progname Nm objpaths Ar full-pathname-to-object-file ... Sets the pathnames of the object files for program .Ar progname . This is normally calculated by prepending the .Em objdir pathname to each file in the .Nm objs list. .El .Pp Only the .Em objpaths parameter is actually needed by .Nm but it is calculated from .Em objdir and .Em objs , which are in turn calculated from .Em srcdir , so is sometimes convenient to specify the earlier parameters and let .Nm calculate forward from there if it can. .Pp The makefile produced by .Nm contains an optional .Ar objs target that will build the object files for each component program by running make inside that program's source directory. For this to work the .Em srcdir and .Em objs parameters must also be valid. If they are not valid for a particular program, that program is skipped in the .Ar objs target. .Sh ENVIRONMENT .Bl -tag -width MAKEOBJDIRPREFIX .It Ev MAKEOBJDIRPREFIX If the environment variable .Ev MAKEOBJDIRPREFIX is set, the object directory will be prefixed with the path contained in this environment variable. .br .Nm Note : This variable is only used if the -o option to use existing object files is also specified. .It Ev MACHINE If the environment variable .Ev MACHINE is set, it is used as the name of the machine type, when accessing object directories of the form obj.MACHINE. If it is not set, it defaults to the machine type returned by .Xr uname 3 . .br .Nm Note : This option is only used if the -o option to use existing object files is also specified. .It Ev MAKE If the environment variable .Ev MAKE is set, it is used as the name of the .Xr make 1 executable to be called. If this environment variable is not set, .Nm defaults to .Dq make . .El .Sh EXAMPLES Here is an example .Em crunchgen input conf file, named .Dq Pa kcopy.conf : .Pp .Bd -literal -offset indent srcdirs /usr/src/bin /usr/src/sbin progs test cp echo sh fsck halt init mount umount myinstall ln test [ # test can be invoked via [ ln sh -sh # init invokes the shell with "-sh" in argv[0] special myprog objpaths /homes/leroy/src/myinstall.o # no sources libs -lutil -lcrypt .Ed .Pp This conf file specifies a small crunched binary consisting of some basic system utilities plus a homegrown install program ``myinstall'', for which no source directory is specified, but its object file is specified directly with the .Em special line. .Pp The crunched binary ``kcopy'' can be built as follows: .Pp .Bd -literal -offset indent % crunchgen -m Makefile kcopy.conf # gen Makefile and kcopy.c % make objs # build the component progams' .o files % make # build the crunched binary kcopy % kcopy sh # test that this invokes a sh shell $ # it works! .Ed .Pp At this point the binary ``kcopy'' can be copied onto an install floppy and hard-linked to the names of the component programs. .Sh SEE ALSO .Xr crunchide 1 , .Xr make 1 .Sh AUTHORS .Nm was written by .An James da Silva Aq jds@cs.umd.edu . .sp 0 Copyright (c) 1994 University of Maryland. All Rights Reserved. .Sh BUGS While .Nm takes care to eliminate link conflicts between the component programs of a crunched binary, conflicts are still possible between the libraries that are linked in. Some shuffling in the order of libraries may be required, and in some rare cases two libraries may have an unresolveable conflict and thus cannot be crunched together. .Pp Some versions of the .Bx build environment do not by default build the intermediate object file for single-source file programs. The ``make objs'' target must then be used to get those object files built, or some other arrangements made. .Pp If a program directory being searched for is found, but contains no objects, other directories are not searched. This causes the following directive to fail: .Pp .Bd -literal -offset indent srcdirs /usr/src/usr.bin /usr/src/usr.bin/less progs less gzip .Ed .Pp as the .Pa /usr/src/usr.bin/less directory will be found with the .Pa /usr/src/usr.bin .Em srcdirs entry, and as it does not contain the require objects, .Nm fails to find objects for the .Em less program. To avoid this problem, list specific srcdirs first, and the more general ones later, for eg: .Pp .Bd -literal -offset indent srcdirs /usr/src/usr.bin/less /usr/src/usr.bin progs less gzip .Ed .Pp will not have the above problem.