1 \input texinfo @c -*-texinfo-*-
3 @setfilename omk-manual
4 @settitle OMK: Ocera Make System
8 Manual for Ocera Make System (OMK)
10 Copyright @copyright{} 2007 Michal Sojka, Pavel Pisa
14 @title Ocera Make System Manual
16 @vskip 0pt plus 1filll
23 @node Top, Overview of OMK, (dir), (dir)
24 @top Ocera Make System
38 @node Overview of OMK, OMK User's Manual, Top, Top
42 OMK is an advanced make system written entirely in GNU make. Compiling
43 software using OMK requires only GNU make binary and standard UNIX
44 utilities (@command{sh}, @command{sed}, @command{cmp} and
45 @command{tr}@footnote{@command{tr} is needed only for OMK to be
46 compatible with MinGW.}) installed. OMK aims to be developer friendly;
47 to use OMK, you do not need to understand (sometimes) cryptic syntax of
50 You can use OMK on all platforms where you can run GNU Make including
51 Cygwin and MinGW. MS DOS was not tested.
57 @c Easy to use for beginners.
59 @c Automatic handling of dependencies.
61 @c Supported host platforms: all Un*x operating system including Linux,
62 @c Cygwin, MS DOS and maybe others.
71 @node Why to Use OMK?, Quick Start, Overview of OMK, Overview of OMK
72 @section Why to Use OMK?
74 Here we list some of OMK features, which we think are important for
75 choosing of a make system.
80 Makefile in source directories are usually very @b{simple}.
82 There is only @b{one} @file{Makefile.rules} for most of components of
85 OMK greatly simplifies compilation of projects, where source files are
86 spread between @b{multiple directories}.
88 OMK handles properly @b{dependencies} of source files and libraries,
89 so it is not necessary to recompile the whole project if only several
92 OMK allows to freely @b{move} cross-dependant components @b{in
93 directory structure} without the need to update users of moved
94 component. I hate something like
95 @option{-I../../sched/rtlshwq/include} in makefiles for example. If a
96 component is renamed or version is added to the name, many Makefiles
97 in the project would require an update.
99 The above feature is very helpful in @b{combining components}
100 (libraries) from different projects/developers to a single project by
101 simply creating symbolic links to external components.
103 Compilation of an OMK based projects don't require to install any
104 files before successful finish of build.
106 OMK allows to call @command{make} for a particular subdirectory in the
109 Under OMK all products of compilation are stored @b{out of source
110 directories}. This simplifies work with version control systems and
111 helps when simultaneous compilation for multiple targets/platforms is
116 @node Quick Start, History, Why to Use OMK?, Overview of OMK
119 If you get some sources, which are distributed with OMK, usually the
120 following commands are sufficient to compile the whole project.
129 @noindent To use OMK in your own project, follow these steps:
133 Take appropriate @file{Makefile.rules}, put it together with leaf
134 @file{Makefile} to the root directory of your project.
136 Create @file{Makefile.omk} files in all directories you want to
137 compile something. Please refer to @ref{OMK User's Manual} to learn
138 what to write in @file{Makefile.omk} files.
140 Run @command{make omkize} in the root directory.
143 @noindent Your project is now ready to compile.
146 @node History, , Quick Start, Overview of OMK
149 OMK was originally written by Pavel Pisa as a solution to have one
150 common make system for OCERA project, where we needed to compile
151 user-space programs, Linux kernel modules and RT Linux modules in one
152 package. Although this system was not accepted for the whole OCERA
153 project. Several individual developers (mostly from Czech Technical
154 University) liked it and started to use it.
156 As a number of projects using OMK grew it was necessary to modularize
157 the make system to support more ``targets''. Michal Sojka took care
158 about the process of modularization.
160 @node OMK User's Manual, Original README, Overview of OMK, Top
161 @chapter OMK User's Manual
166 * Compiling Programs::
168 * Multiple Directories::
169 * Dependency Tracking::
170 * Configuration and Conditional Compilation::
171 * Advanced OMK Features::
172 * Running OMK under Windows OS::
173 * Interfacing OMK to popular IDEs::
177 @node Basic Concepts, Invoking OMK, OMK User's Manual, OMK User's Manual
178 @section Basic Concepts
180 The main concept of OMK is very simple. In the root directory of the
181 projects resides a file called @file{Makefile.rules}. This file contains
182 all compilation rules needed for compilation of a particular
183 project. There are different @file{Makefile.rules} for different
184 platforms (Unix, RTEMS, system-less, ...). In every subdirectory a
185 @file{Makefile.omk} is stored. This file determines what should be done
186 in the respective directory (e.g. compile a program from several source
187 files). Its syntax is very simple -- see the following sections.
189 Since make searches by default for a @file{Makefile} and not for
190 @file{Makefile.rules} or @file{Makefile.omk}, there must be a small
191 generic @file{Makefile} in every directory, whose task is only to find
192 @file{Makefile.rules} in the actual or any parent directory and include
193 it. This search is performed only once at the beginning of compilation.
195 @c TODO: Pavel's note about qmake.
197 The compilation process itself is comprised of several passes. Every
198 pass traverses the whole directory structure@footnote{In future, we are
199 planning some optimization that allows OMK to traverse the directories
200 only once and thus decrease compilation time.} and does a particular
201 task in every directory of the project. Typically, these passes are:
203 @anchor{include-pass}
205 This pass takes all include files marked for ``export'' and copies
206 (or links) them to the @file{include} directory under
207 @file{_compiled} directory. @xref{Header Files}.
209 Also, during this pass, automatically generated header file are
210 generated according to the current
211 configuration. @xref{Configuration and Conditional Compilation}.
213 During this pass, all include files are in place, so all libraries
216 Finally, programs can be compiled and linked against libraries
217 created in the previous pass.
220 The results of compilation are stored under the @file{_compiled}
221 directory. This directory is structured as a classical Unix file-system
222 (it contains directories like @file{bin}, @file{lib} and @file{include})
223 and can be directly copied to the target device or to some directory on
224 a host computer (e.g. @file{/usr/local}).
226 Besides @file{_compiled} directory, there in a @file{_build}
227 directory. Under this directory are stored some temporary files and
228 intermediate compilation products (object files, dependency files etc.).
230 In the next section, we provide an overview of methods, how to invoke
231 OMK from command line. Section @ref{Interfacing OMK to popular IDEs}
232 covers running of OMK from popular IDEs.
234 Sections @ref{Compiling Programs} through @ref{Configuration and
235 Conditional Compilation} deals with the content of
236 @file{Makefile.omk}. Its syntax in usual cases compatible to GNU
237 Automake's @file{Makefile.am} syntax. Also, the scheme for naming
238 variables was inspired by Automake so most OMK variables have the name
239 like @samp{@var{target}_@var{TYPE}}.
241 @node Invoking OMK, Compiling Programs, Basic Concepts, OMK User's Manual
242 @section Invoking OMK
244 Before using OMK for the first time, you have to call:
246 @command{make default-config}
248 @noindent See @ref{Configuration and Conditional Compilation} for
249 details. If you forget to do this, OMK will notice you.
251 To compile the whole project or only some subtree of the project, call
255 @noindent in the appropriate directory.
257 To clean files in @file{_build} directory but not in @file{_compiled}
263 To clean the compilation completely, you can either remove
264 @file{_compiled} and @file{_build} directories manually, or call
266 @command{make distclean}
268 @noindent which does the same. This command removes these directories
269 even if you call it from a subdirectory.
271 To debug compilation problems, you can use @code{V} variable (see
277 You can also set values of some other variables on command line for
278 temporary change something. The example below compiles the code
279 temporarily with debugging information:
281 @command{make CFLAGS="-g -O0 -Wall"}
284 If your project uses an alternative make-system (e.g. Automake or custom
285 makefiles), it might be useful for you to use the command:
287 @command{make omkize}
289 @noindent This will find all @file{Makefile.omk} files in all subdirectories
290 and copies generic @file{Makefile} from the root directory to that
291 subdirectories. This way you can easily switch your project to use OMK.
297 If this variable equals to @samp{1}, the whole command lines for all
298 executed commands are displayed. When not set or zero, only short
299 messages are printed. Value of @samp{2} displays the whole command lines
300 as with @samp{1} and in addition directory navigation messages are
304 @node Compiling Programs, Libraries, Invoking OMK, OMK User's Manual
305 @section Compiling Programs
307 To tell OMK to compile a program, you need to set some variables in
308 @file{Makefile.omk} (usually) in the directory where program sources are
311 In the example bellow a program @command{test} will be compiled from
312 source @file{test.c}.
315 @verbatiminclude ../tests/programs/Makefile.omk
318 @noindent The variables are:
320 @anchor{bin_PROGRAMS}
322 Contains a list of names (whitespace separated) of programs to be
323 compiled in this directory.
326 @defvar test_PROGRAMS
327 Almost the same as @ref{bin_PROGRAMS}, but resulting binaries are
328 stored in @file{bin-tests} directory instead of @file{bin}. This
329 variable is intended for various test programs not to be mixed with
333 @defvar utils_PROGRAMS
334 Almost the same as @ref{bin_PROGRAMS}, but resulting binaries are
335 stored in @file{bin-utils} directory instead of @file{bin}. This
336 variable is intended for various development utilities not to be mixed
337 with the final product.
341 For every program name @var{xxx} in @code{bin_PROGRAMS},
342 @code{test_PROGRAMS} or @code{utils_PROGRAMS}, this variable contains
343 a list of sources that are needed to compile the program. OMK uses an
344 extension of the filename to determine the compiler to compile this
349 This variable contains a list of libraries the program @var{xxx} will
358 This variable contains a list of libraries all programs in this
359 directory needs to be linked to.
363 Directives passed to the C or C++ compiler with additional directories
364 to be searched for header files. In most cases you need to specify an
365 absolute path. To specify a directory relative to the source
366 directory, you can use the @code{$(SOURCES_DIR)} variable, which
367 refers to the directory, where @file{Makefile.omk} is located. This
368 variable applies to all compilations invoked in the current directory.
371 INCLUDES = -I$(SOURCES_DIR)/my_include_dir
376 Directives passed to the C or C++ compiler with preprocessor macro
377 definitions. This variable applies to all compilations invoked in the
386 @c FIXME: INCLUDES variable should not be set by rtlinux rules.
388 @node Libraries, Multiple Directories, Compiling Programs, OMK User's Manual
392 With OMK, you can easily create statically or dynamically linked
393 libraries. The way of creating libraries is very similar to how programs
394 are created. @xref{Compiling Programs}.
396 In @file{Makefile.omk}, you specify several variables, which defines how
397 the libraries should be compiled. In the example below the library
398 @samp{mylib} is created from two sources @file{funca.c} and
399 @file{funcb.c}. Interface of this library is defined in
400 @file{myfunc.h}. Therfore, we export this header for use by other
404 @verbatiminclude ../tests/libraries/Makefile.omk
407 @noindent Variables for use with libraries are:
409 @defvar lib_LIBRARIES
410 Specifies a list of statically linked libraries to be compiled.
413 @defvar shared_LIBRARIES
414 Specifies a list of dynamically linked libraries to be compiled.
418 For every library name @var{xxx} in @code{lib_LIBRARIES} or
419 @code{shared_LIBRARIES}, this variable contains a list of sources that
420 are needed to compile the library. OMK uses an extension of the
421 filename to determine the compiler to compile this source.
428 @node Header Files, , Libraries, Libraries
429 @subsection Header Files
431 C and C++ libraries are not very useful without header files. OMK
432 provides several variables that specify activities on header files.
434 During compilation, header files are copied (or linked) from source
435 directories to the @file{_compiled} tree
436 (see @ref{include-pass}). Libraries and programs are then compiled against
439 @anchor{include_HEADERS}
440 @defvar include_HEADERS
441 Specifies the list of header files to be exported for use by other
442 libraries/programs. The files are exported directly to the
443 @file{include} directory even if the file is located in a subdirectory
444 (like @file{sci_regs.h} in the example below)
447 include_HEADERS = regs.h periph/sci_regs.h
451 @defvar nobase_include_HEADERS
452 Similar to @ref{include_HEADERS}, but the directory prefix is always
453 kept. To include the file exported by this variable, use
454 @code{#include <@var{prefix}/@var{header.h}>}.
457 @defvar renamed_include_HEADERS
458 Exports the header files under different name. The form of the items
459 in this whitespace separated list is: @var{real name}@code{->}@var{new
463 renamed_include_HEADERS = orte_config_omk_win32.h->orte_config.h
468 If this variable equals to @samp{y}, symbolic links to headers in
469 source directories are used in @file{_compiled} tree instead of
472 Normally, the header files are copied into @file{_compiled} directory
473 to be prepared for transfer into target location afterwards. Copying
474 ensures that resulting libraries are in correspondence with the header
475 files even if the header is changed by a developer but the library is
478 @c Another reason for having single include directory for the whole
479 @c project is tat every component knows where to find header files of
482 On the other side, the copying could make problems during
483 development. Most @acronym{IDE}s, allows you to jump directly to the
484 place, where an error is reported by the compiler. If the error is in
485 a header file, IDE opens you the copy of the header file. If you
486 correct the error there, after the next compilation, your header file
487 will be overwritten by the old version from your source tree.
489 This option is not typically used in @file{Makefile.omk}, but in the
490 top level configuration file @file{config.omk} or on command line.
493 @node Multiple Directories, Dependency Tracking, Libraries, OMK User's Manual
494 @section Multiple Directories
496 OMK is probably most useful in projects consisting of multiple
497 directories. For such projects, it is not easy to write from scratch
498 classic Makefiles that provides all the needed features.
500 You can instruct OMK to descend to a (sub)directory by setting the
501 @code{SUBDIRS} variable in @file{Makefile.omk}.
504 This variable contains a list of directories, in which compilation
505 must be also invoked. Usually, names of subdirectories are used, but
506 you can use any path specification here.
508 Compilation is invoked in these directories before it is invoked in
509 the current directory.
511 @c TODO: Write tests for this.
513 @defvar ALL_OMK_SUBDIRS
514 This variable is set by OMK and can be used as the value of
515 @code{SUBDIRS} variable. It contains a list of all direct
516 subdirectories, which contain @file{Makefile.omk}. This is especially
517 useful if you are combining several projects or components
518 together. In the root directory of your project, you just create
519 symbolic links the components from other projects and all the linked
520 directories automatically appears as the value of this variable.
523 SUBDIRS = $(ALL_OMK_SUBDIRS)
527 @node Dependency Tracking, Configuration and Conditional Compilation, Multiple Directories, OMK User's Manual
528 @section Dependency Tracking
530 OMK automatically handles tracking of dependencies of files in compiled
531 projects. It uses gcc's @option{-M@var{x}} options to do this for object
532 files. This way, whenever you change some header file, OMK recompiles
533 only those files, where the changed header was really included.
535 Dependencies are also maintained for libraries and binaries. To find the
536 dependencies, OMK parses linker map files, so a change to some library
537 causes recompilation of all programs using that library.
539 @node Configuration and Conditional Compilation, Advanced OMK Features, Dependency Tracking, OMK User's Manual
540 @section Configuration and Conditional Compilation
542 In many projects, it is necessary to configure a compilation process. By
543 this configuring we mean, setting some parameters that influence the
544 output of compilation process. In GNU projects, @command{configure}
545 script is usually responsible for configuration. User provides some
546 parameters to @command{configure}, which is run before compilation, and
547 this script does all steps needed to configure the sources and
548 make-system in the desired way.
550 OMK has its own configuration mechanism, which is described in this
551 section. For future releases, we plan that this mechanism can make use
552 of GNU Autoconf, but currently there is no directly integrated support
555 In every directory you can specify some configuration parameters, which
556 can be modified by a user. Then, when @command{make default-config} is
557 run, all these parameters are found and together with their default
558 values are stored as makefile variables in
559 @file{config.omk-default}. This file is included during compilation, so
560 if you don't specify other values, these defaults are used. If you are
561 not satisfied with these defaults, you can override the values of
562 parameters in @file{config.omk}. This file is also included during
563 compilation and variables mentioned there takes precedence over those
564 specified in @file{config.omk-default}. Both @file{config.omk} and
565 @file{config.omk-default} have to be stored in the same directory as
566 @file{Makefile.rules}.
568 Besides overriding the default values of configuration parameters,
569 @file{config.omk} can also be used as a common place to store some
570 global settings that applies to the whole project, e.g. the compiler to
571 use or common compiler flags.
573 @subsection Specifying Configuration Parameters
575 To specify names and default values of configuration parameters use the
576 @code{default_CONFIG} variable in @file{Makefile.omk}.
578 @defvar default_CONFIG
579 This variable contains a list of configuration parameters and their
580 default values. The format of every item in this list is
581 @var{CONFIG_xxxx}=@var{value}. You can name the parameter as you want,
582 but it is good practice to start the name with @samp{CONFIG_} prefix.
584 OMK can automatically generate header files, with C preprocessor macro
585 definitions according to the OMK's configuration parameters. The
586 actual content of generated header files depends on the form of the
587 @var{value}. The possible forms are:
590 @item @samp{y}, @samp{n} or @samp{x}
591 This defines boolean parameters. If the value of the parameter is
592 @samp{y}, the @samp{#define CONFIG_@var{xxx} 1} is generated, if it is
593 @samp{n}, no @code{#define} is generated.
595 @samp{x} is a special value called @emph{recessive 'n'}. The meaning
596 is that this parameter influences the component in the current
597 directory (i.e. the corresponding @code{#define} will be included in
598 @code{LOCAL_CONFIG_H}; see @ref{LOCAL_CONFIG_H}) but the default value
599 is not specified here. If the default value is not specified anywhere,
600 the behavior is the same as if @samp{n} is specified.
602 Numeric parameters. The define looks like @samp{#define CONFIG_@var{xxx} @var{number}}
604 Text without quotes. The define looks like @samp{#define CONFIG_@var{xxx} @var{text}}
606 Text with quotes. The define looks like @samp{#define CONFIG_@var{xxx} "@var{text}"}
610 @noindent Example of using @code{default_CONFIG}. @file{Makefile.omk} reads like:
612 @verbatiminclude ../tests/config/default/Makefile.omk
614 @noindent and @file{subdir/Makefile.omk} like:
616 @verbatiminclude ../tests/config/default/subdir/Makefile.omk
619 @noindent After running @command{make default-config}, the content of
620 @file{config.omk-default} will be:
622 @verbatiminclude ../tests/config/default/config.omk-correct
625 @subsection Using Configuration Parameters
627 Configuration parameters can be used in two ways:
630 as variables in @file{Makefile.omk} and
632 as C/C++ preprocessor macros in OMK generated header files.
635 @noindent For the first use, your @file{Makefile.omk} may contain something like:
637 SUBDIRS = arch/$(CONFIG_ARCH)
639 ifeq ($(CONFIG_DEBUG),y)
640 DEFS += -DUSE_SIMULATOR
644 @noindent For the second use, there are several variables that control
645 the generation of header files with configuration values. These
646 variables are described here:
648 @anchor{LOCAL_CONFIG_H}
649 @defvar LOCAL_CONFIG_H
650 The value of this variable is the name of a header file, which will
651 contain all configuration parameters declared in the current directory
652 by @code{default_CONFIG}. This header file is accessible only by files
653 in the current directory and it should be included like @code{#include
656 In @file{Makefile.omk}, the use of this variable can look like this:
659 LOCAL_CONFIG_H = myconfig.h
663 @defvar config_include_HEADERS
664 This variable is similar to @code{LOCAL_CONFIG_H}. One difference is
665 that the generated header file is accessible to all sub-projects in
666 all directories, not only to the files in the same directory (the
667 header is stored in @file{_compiled} tree). The second difference is
668 that you have to specify, which configuration parameters you want to
669 appear in the header file.
673 This variable determines the configuration parameters that should be
674 stored in a header file specified by
675 @code{config_include_HEADERS}. The @var{xxx} in the name of this
676 variable needs to be the same as the base name (without extension) of
680 @noindent Example of using @code{config_include_HEADERS}:
682 default_CONFIG = CONFIG_LINCAN=y CONFIG_LINCANRTL=n CONFIG_LINCANVME=n
683 config_include_HEADERS = global.h
684 global_DEFINES = CONFIG_OC_LINCAN CONFIG_OC_LINCANRTL
687 @noindent Here, we include only two out of the three configuration
688 parameters defined in the current @file{Makefile.omk}. It is also
689 possible to include configuration parameters defined in a different
692 @subsection Common Variables
694 It is common practice to use @file{config.omk} to store project-wide
695 settings. Here is the list of variables, which are commonly set here
696 (but they can also be set elsewhere, e.g. in @file{Makefile.omk}).
698 You can easily ``reconfigure'' your project by changing the
699 @file{config.omk} file. It is useful to have several configurations
700 stored in different files and let @file{config.omk} be a symbolic link
701 to the desired configuration.
705 The name of C compiler.
707 Command line options for C compiler.
709 The name of C++ compiler.
711 Additional parameters (besides @code{CFLAGS}) to by passed to C++
715 @node Advanced OMK Features, Running OMK under Windows OS, Configuration and Conditional Compilation, OMK User's Manual
716 @section Advanced OMK Features
718 In this section we list several OMK features, which are more complicated
719 or rarely used so they were omitted in previous sections.
723 The @file{_compiled} directory can be shared between multiple projects
724 (by using symbolic links).
727 If you work on a bigger project, you usually don't need to rebuild the
728 whole project and call @command{make} only in a
729 subdirectory. Sometimes, it might be useful to rebuild the whole
730 project. You can either change working directory to the root of your
731 project and call @command{make} there or, as a shortcut, you can use
732 @code{W} variable (see @ref{W}) to compile everything directly from a
739 Searching for @file{Makefile.rules} works such way, that if you get
740 into sources directory over symbolic links, OMK is able to unwind your
741 steps back. This implies you can make links to component directories
742 on read-only media, copy @file{Makefile.rules}, @file{Makefile} and
743 top-level @file{Makefile.omk}, adjust @file{Makefile.omk} to contain
744 only required components and then call @command{make} in the top
745 directory or even in read-only directories after changing working
746 directory from your tree to readonly media.
752 If this variable equals to @samp{1}, the @b{whole} project is
753 (re)compiled, even if @command{make} is called from a subdirectory.
759 @node Running OMK under Windows OS, Interfacing OMK to popular IDEs, Advanced OMK Features, OMK User's Manual
760 @section Running OMK under Windows OS
762 @node Interfacing OMK to popular IDEs, Troubleshooting, Running OMK under Windows OS, OMK User's Manual
763 @section Interfacing OMK to popular IDEs
767 KDevelop has support for custom build systems. To use KDevelop to
768 develop projects using OMK follow these steps. These steps are valid for
769 version 3.5.0 of KDevelop, but for previous versions it doesn't differ
774 Import project to KDevelop (from menu choose @emph{Project---Import
775 existing project}). Select the type of project to @emph{Generic C
776 Application (Custom Buildsystem)}.
782 Then answer to following dialogs as you want.
787 @image{kdevelop3} @image{kdevelop4}
791 If you are working only on some small part of the bigger project, you
792 usually don't want to recompile the whole project every time. In
793 @emph{Project---Project Options}, you can specify the subdirectory where to
800 If you want to switch between several configurations easily (see also
801 @ref{Configuration and Conditional Compilation}), in the same dialog
802 you can add @option{-e} to make options. This makes environment variables
803 have higher precedence than those in @file{config.omk-default}. Then,
804 you can define several environments with different
805 @code{CONFIG_@var{xxx}} variables and their values.
811 You can easily switch the configurations from @emph{Build---Make
821 @subsection Emacs, VIM, etc.
823 Since OMK compilation is started by executing @command{make} command,
824 many common editors can work easily with OMK.
826 Under Emacs, you can use @command{compile} or @command{recompile}
827 commands as you are used to do.
829 @node Troubleshooting, , Interfacing OMK to popular IDEs, OMK User's Manual
830 @section Troubleshooting
834 If you rename some file or directory and then you can't compile your
835 project, call @command{make clean} in the directory with errors. The
836 reason for this behavior is that OMK remembers dependencies of every
837 file. After renaming something, the original name is still stored in
838 dependencies, but make doesn't know how to create this non-existent
842 Sometimes, you may want to compile one file the same way as OMK does
843 it, but run the compilation manually from command line. For example,
844 you want to debug some preprocessor macros and you only want to
845 produce preprocessed source instead of object file.
847 To compile something manually, you can run OMK with @command{make
848 V=2}. This will print all commands executed together with directory
849 navigation messages. Find the command you want to execute manually in
850 the output. To run it, you need to change the working directory to the
851 correct one in the @file{_build} tree. The correct directory can be
852 found in make output on the line @samp{Entering directory} preceding
856 @node Original README, OMK Development, OMK User's Manual, Top
857 @chapter Original README
859 Since this manual still doesn't cover all aspects of OMK, we include
860 here a @file{README.rules} file, which was written for the first version
863 @b{Important notice:} This make system uses features found in recent
864 versions of GNU Make program. If you encounter problems with package
865 building, check, that you use correct version of Make program. The
866 Make older than version 3.80, could not be used. Even Make version
867 3.80 has annoying bug which causes building fail with misleading
868 message "virtual memory exhausted". Please, upgrade at least to
869 version 3.81 of GNU Make.
871 There is list of features which we want to solve with our make system:
874 Central @file{Makefile.rules} for most of components of a bigger project.
876 FIXME (our CAN framework includes more libraries common with our other
877 projects, we need to separate some utility libraries etc.)
879 The rules in more spread Makefiles are way to the hell (update for
880 different kernel, RT-Linux etc would be nightmare in other case).
882 Make system should allow to freely move cross-dependant components in
883 directory structure without need to update users of moved component (I
884 hate somethink like @option{-I../../sched/rtlshwq/include} in CAN makefiles for
885 example. If a component is renamed or version is added to then name,
886 all Makefiles in CAN will require update).
888 Make system should be able to compile mutually cross-dependant
889 libraries and should ensure, that change in one component sources or
890 headers would result in relink or rebuild in components linked against
891 that library or including modified header file.
893 Make system has to enable compilation out of OCERA full source tree
894 (we would lost many users of particular components in other case).
896 Compile should be able to do all above work without need to install
897 any files before successful finish of build.
899 Because we use some libraries for RT-Linux build and user-space build,
900 we need to solve how to compile from same sources to both targets.
902 The build system should allow to call make for particular source
903 subdirectory. Time of recursive make through all subdirectories is
906 Make system should enable to build out of sources tree (else clean or
907 working with CVS sandbox gets fussy and simultaneous multiple targets
910 It would be good, if there is a possibility to call make from
911 read-only media sources.
913 Make system should store results of build in some separate directory
914 structure to simple install and testing.
916 Makefiles in sources directories should be simple.
919 There is probably only one alternative fully supporting above requirements
920 and it is GNU Autoheader...Automake...Autoconf... system.
921 But it is complicated and requires big amount of support files.
922 It would be acceptable if it could be easily used for OCERA framework.
923 But there are important show stoppers for that system:
926 It would require deep revision of all OCERA CVS contents and agreement
927 on this would be problematic
929 This system is not well prepared for dual compilation for Linux and
930 RT-Linux sub-targets. It would mean many changes in default autoconf
931 setup to support this. Probably simplest way would be to rebuild GCC
932 tool chain for something like i586-elf-rtlinux. This would require
933 even more space for OCERA development.
936 The problem calls for some solution, which would have minimal impact
937 on other components and would be elegant and would be maintainable
938 and small, because our main goal is components development and not
939 make systems development.
941 There is result of our trial. It is OMK make system.
942 The @file{Makefile} and @file{Makefile.omk} files should be in all source
943 directories. Common @file{Makefile.rules} file is required in the toplevel
944 sources directory. Alternatively this file could be moved
945 to link tree pointing into readonly media or can be anywhere
946 else if @code{MAKERULES_DIR} and @code{SOURCES_DIR} are specified.
948 @c !!! tohle tam nejak zmizelo, mozna by to chtelo skontrolovat, ze to
949 @c sedi s aktualnim stavem
952 Syntax of Makefile.omk files is for usual cases compatible
953 to Automake's Makefile.am descriptions. There are specific targets
954 for RT-Linux and Linux kernel related stuff
956 Makefile.omk user defined variables
959 list of subdirectories intended for make from actual directory
961 list of the user-space libraries
962 @item shared_LIBRARIES
963 list of the user-space shared libraries
964 @item kernel_LIBRARIES
965 list of the kernel-space libraries
966 @item rtlinux_LIBRARIES
967 list of the RT-Linux kernel-space libraries
968 @item include_HEADERS
969 list of the user-space header files
970 @item nobase_include_HEADERS
971 headers copied even with directory part
973 list of the kernel-space header files
974 @item rtlinux_HEADERS
975 list of the RT-Linux kernel-space header files
977 list of the require binary programs
979 list of the development utility programs
981 list of the kernel side modules/applications
982 @item rtlinux_MODULES
983 list of RT-Linux the kernel side modules/applications
985 list of specific target sources
987 additional include directories and defines for user-space
988 @item kernel_INCLUDES
989 additional include directories and defines for kernel-space
990 @item rtlinux_INCLUDES
991 additional include directories and defines for RT-Linux
993 list of default config assignments CONFIG_XXX=y/n ...
996 The Makefile is same for all sources directories and is only 14 lines
997 long. It is there only for convenience reasons to enable call "make"
998 from local directory. It contains code which locates
999 @file{Makefile.rules} in actual or any parent directory. With standard
1000 BASH environment it works such way, that if you get into sources
1001 directory over symbolic links, it is able to unwind yours steps back
1002 => you can make links to readonly media component directories, copy
1003 @file{Makefile.rules}, Makefile and toplevel Makefile.omk, adjust
1004 Makefile.omk to contain only required components and then call make in
1005 top or even directories after crossing from your tree to readonly
1008 The system compiles all files out of source directories. The actual
1009 version of system is adapted even for OCERA tree mode if
1010 @code{OCERA_DIR} variable is defined in @file{Makefile.rules}
1012 There are next predefined directory name components, which can be
1016 @item BUILD_DIR_NAME = _build
1017 prefix of directory, where temporary build files are stored
1018 @item COMPILED_DIR_NAME = _compiled
1019 prefix of directory, where final compilation results are stored
1020 @item GROUP_DIR_NAME = yyy
1021 this is used for separation of build sub-trees in OCERA environment
1022 where more @file{Makefile.rules} is spread in the tree
1025 Next directories are used:
1028 @item KERN_BUILD_DIR := $(MAKERULES_DIR)/$(BUILD_DIR_NAME)/kern
1029 directory to store intermediate files for kernel-space targets
1030 @item USER_BUILD_DIR := $(MAKERULES_DIR)/$(BUILD_DIR_NAME)/user
1031 directory to store intermediate files for user-space targets
1033 @item USER_INCLUDE_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/include
1034 directory to store exported include files which should be installed later
1035 on user-space include path
1036 @item USER_LIB_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/lib
1037 same for user-pace libraries
1038 @item USER_UTILS_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/bin-utils
1039 utilities for testing, which would not probably be installed
1040 @item USER_BIN_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/bin
1041 binaries, which should go into directory on standard system PATH
1042 (/usr/local/bin, /usr/bin or $(prefix)/bin)
1044 @item KERN_INCLUDE_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/include-kern
1045 directory to store exported include files which should be installed later
1046 on kernel-space include path
1047 @item KERN_LIB_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/lib-kern
1048 same for kernel-pace libraries
1049 @item KERN_MODULES_DIR := $(MAKERULES_DIR)/$(COMPILED_DIR_NAME)/modules
1050 builded modules for Linux kernel or RT-Linux system
1053 There is more recursive passes through directories to enable
1054 mutual dependant libraries and binaries to compile.
1055 Next passes are defined
1058 @item default-config
1059 generates @file{config.omk-default} or xxx-default (FIXME) configuration file
1061 checks and creates required build directories
1063 copies header files to @code{USER_INCLUDE_DIR} and @code{KERN_INCLUDE_DIR}
1065 builds objects in USER_BUILD_DIR/@var{relative path} and creates libraries
1067 @item binary-pass and utils-pass
1068 links respective binaries in USER_@{BIN,UTILS@}_DIR directory. If some
1069 object file is missing it compiles it in USER_BUILD_DIR/@var{relative path}
1070 @item kernel-lib-pass
1071 builds libraries for kernel space targets
1073 builds kernel modules
1076 The amount of passes is relatively high and consumes some time. But
1077 only other way to support all required features is to assemble one big
1078 toplevel Makefile, which would contain all components and targets
1081 Drawbacks of designed make system
1084 the system is not as fast as we would like
1086 it lacks Autoconf and configure extensive support for many systems
1087 from UNIX to DOS and WINDOWS
1089 it does not contain support for checking existence of target
1090 libraries and functionalities as GNU Autoconf
1092 it is heavily dependant on GNU MAKE program. But it would not be big
1093 problem, because even many commercial applications distribute GNU MAKE
1094 with them to be able to work in non-friendly systems
1096 the key drawback is dependence on recent MAKE version 3.80 and better
1097 and even version 3.80 of MAKE has important bug, which has been
1098 corrected in newer sources (FIXME)
1101 The last point is critical. I have not noticed it first, because
1102 I use Slackware-9.2 and it contains latest released version
1103 of MAKE (version 3.80).
1104 The problem appears when I have tried to build bigger libraries.
1105 There is bug in version 3.80, which results in misleading
1106 error "Virtual memory exhausted". It is known bug with ID 1517
1109 * long prerequisite inside eval(call()) => vm exhausted, Paul D. Smith
1113 I have optimized some rules to not push memory to the edge,
1114 but there could be still issues with 3.80 version.
1116 I have downloaded latest MAKE CVS sources. The compilation required
1117 separate lookup and download for .po files and full Autoheader... cycle.
1118 I have put together package similar to release. Only ./configure --prefix=...
1119 and make is required. CVS sources contains version 3.81beta1.
1120 You can download prepared sources archive from
1121 @indicateurl{http://paulandlesley.org/make/make-3.81beta1.tar.bz2}
1122 Or you can get our local copy from
1123 @indicateurl{http://cmp.felk.cvut.cz/~pisa/can/make-3.81beta1.tar.gz}
1125 The archive contains even "make" binary build by me, which should work
1126 on other Linux distributions as well. Older version of MAKE (3.79.x
1127 released about year 2000) found on Mandrake and RedHat are not
1128 sufficient and do not support eval feature. I do not expect, that
1129 Debian would be more up-to-date or contain fixes to MAKE vm exhausted
1132 The local CTU archive with our CAN components prepared for inclusion
1133 into OCERA SF CVS could be found in my "can" directory
1135 @indicateurl{http://cmp.felk.cvut.cz/~pisa/can/ocera-can-031212.tar.gz}
1137 The code should build for user-space with new make on most of Linux distros
1138 when make is updated.
1140 If you want to test compile for RT-Linux targets, line
1143 #RTL_DIR := /home/cvs/ocera/ocera-build/kernel/rtlinux
1146 in @file{Makefile.rules} has to be activated and updated
1147 to point RT-Linux directory containing "rtl.mk".
1148 There is only one library ("ulutrtl") and test utility compiled for RT-Linux
1149 (@file{can/utils/ulut/ul_rtlchk.c}).
1151 The next line, if enabled, controls compilation in OCERA project tree
1154 #OCERA_DIR := $(shell ( cd -L $(MAKERULES_DIR)/../../.. ; pwd -L ) )
1157 The LinCAN driver has been updated to compile out of source directories.
1159 Please, check, if you could compile CAN package and help us with integration
1160 into OCERA SF CVS. Send your comments and objections.
1162 The OMK system has been adapted to support actual OCERA configuration process.
1163 I am not happy with ocera.mk mix of defines and poor two or three rules,
1164 but OMK is able to overcome that.
1166 The OMK system has integrated rules (default-config) to build default
1167 configuration file. The file is named @file{config.omk-default} for
1168 the stand-alone compilation. The name corresponds to OCERA config +
1169 "-default" if OCERA_DIR is defined. This file contains statements
1170 from all @code{default_CONFIG} lines in all @file{Makefile.omk}. The
1171 file should be used for building of own @file{config.omk} file, or as
1172 list for all options if Kconfig is used.
1174 @c @chapter OMK Reference
1176 @node OMK Development, Variable Index, Original README, Top
1177 @chapter OMK Development
1181 @node Variable Index, , OMK Development, Top
1182 @unnumbered Variable Index
1186 @c @node Concept Index, , Variable Index, Top
1187 @c @unnumbered Concept Index