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1@c
2@c  COPYRIGHT (c) 1989-2010.
3@c  On-Line Applications Research Corporation (OAR).
4@c  All rights reserved.
5
6@chapter Directory Structure
7
8The RTEMS directory structure is designed to meet
9the following requirements:
10
11@itemize @bullet
12@item encourage development of modular components.
13
14@item isolate processor and target dependent code, while
15allowing as much common source code as possible to be shared
16across multiple processors and target boards.
17
18@item allow multiple RTEMS users to perform simultaneous
19compilation of RTEMS and its support facilities for different
20processors and targets.
21@end itemize
22
23The resulting directory structure has processor and
24board dependent source files isolated from generic files.  When
25RTEMS is configured and built, object directories and
26an install point will be automatically created based upon
27the target CPU family and BSP selected. 
28
29The placement of object files based upon the selected BSP name
30ensures that object files are not mixed across CPUs or targets.
31This in combination with the makefiles allows the specific
32compilation options to be tailored for a particular target
33board.  For example, the efficiency of the memory subsystem for
34a particular target board may be sensitive to the alignment of
35data structures, while on another target board with the same
36processor memory may be very limited.  For the first target, the
37options could specify very strict alignment requirements, while
38on the second the data structures could be @i{packed} to conserve
39memory.  It is impossible to achieve this degree of flexibility
40without providing source code.
41
42The RTEMS source tree is organized based on the following variables:
43
44@itemize @bullet
45
46@item functionality,
47@item target processor family,
48@item target processor model,
49@item peripherals, and
50@item target board.
51
52@end itemize
53
54Each of the following sections will describe the
55contents of the directories in the RTEMS source
56tree.  The top of the tree will be referenced
57as @code{$@{RTEMS_ROOT@}} in this discussion.
58
59@c
60@c  Top Level Tree
61@c
62
63@c @ifset use-ascii
64@example
65@group
66                      rtems-VERSION
67                           |
68   +--------+----+----+----+--+-----+---+-------+--------+
69   |        |    |    |       |     |   |       |        |
70aclocal automake c contrib  cpukit doc make testsuites tools
71@end group
72@end example
73@c @end ifset
74
75@ifset use-tex
76@end ifset
77
78@ifset use-html
79@html
80@end html
81@end ifset
82
83@table @code
84@item $@{RTEMS_ROOT@}/aclocal/
85This directory contains the custom M4 macros which are available to
86the various GNU autoconf @code{configure.ac} scripts throughout
87the RTEMS source tree.  GNU autoconf interprets @code{configure.ac}
88files to produce the @code{configure} files used to tailor
89RTEMS build for a particular host and target environment.  The
90contents of this directory will not be discussed further in this
91document.
92
93@item $@{RTEMS_ROOT@}/automake/
94This directory contains the custom GNU automake fragments
95which are used to support the various @code{Makefile.am}
96files throughout the RTEMS source tree.  The
97contents of this directory will not be discussed
98further in this document.
99
100@item $@{RTEMS_ROOT@}/c/
101This directory is the root of the portions of the RTEMS source
102tree which must be built tailored for a particular CPU model
103or BSP.  The contents of this directory will be discussed
104in the @ref{Directory Structure c/ Directory} section.
105
106@item $@{RTEMS_ROOT@}/contrib/
107This directory contains contributed support software.  Currently
108this directory contains the RPM specifications for cross-compilers
109hosted on GNU/Linux that target various operating systems
110including MinGW, Cygwin, FreeBSD, and Solaris.  The
111cross-compilers produced using these specifications are then
112used in a Canadian cross build procedure to produce the various
113RTEMS toolsets on a GNU/Linux host. 
114
115This directory also contains RPM specifications for the
116prebuilt cross-compilation toolsets provided by the
117RTEMS project.  There are separate subdirectories
118for each of the components in the RTEMS Cross Compilation
119Environment unde the  @code{contrib/crossrpms/} directory.
120This directory is configured, built, and installed separately
121from the RTEMS executive and tests.  This directory will not
122be discussed further in this document.
123
124
125@item $@{RTEMS_ROOT@}/cpukit/
126This directory is the root for all of the "multilib'able"
127portions of RTEMS.  This is a GNU way of saying the
128contents of this directory can be compiled like the
129C Library (@code{libc.a}) and the functionality is
130neither CPU model nor BSP specific.  The source code
131for most RTEMS services reside under this directory.
132The contents of this directory will be discussed
133in the @ref{Directory Structure CPU Kit Directory} section.
134
135@item $@{RTEMS_ROOT@}/doc/
136This directory is the root for all RTEMS documentation.
137The source for RTEMS is written in GNU TeXinfo and
138used to produce HTML, PDF, and "info" files.
139The RTEMS documentation is configured, built,
140and installed separately from the RTEMS executive and tests.
141The contents of this directory will be discussed
142in the @ref{Directory Structure Documentation Directory} section.
143
144@item $@{RTEMS_ROOT@}/make/
145This directory contains files which support the
146RTEMS Makefile's.  From a user's perspective, the
147most important parts are found in the @code{custom/}
148subdirectory.  Each ".cfg" file in this directory
149is associated with a specific BSP and describes
150the CPU model, compiler flags, and procedure to
151produce an executable for the target board.
152These files are described in detail in the
153@b{RTEMS BSP and Device Driver Development Guide}
154and will not be discussed further in this document.
155
156@item $@{RTEMS_ROOT@}/testsuites/
157This directory contains the test suites for the
158various RTEMS APIs and support libraries.  The
159contents of this directory are discussed in the
160@ref{Directory Structure testsuites/ Test Suites} section.
161
162@item $@{RTEMS_ROOT@}/tools/
163This directory contains RTEMS specific support utilities which
164execute on the development host.  These utilities are divided
165into subdirectories based upon whether they are used in the process
166of building RTEMS and applications, are CPU specific, or are
167used to assist in updating the RTEMS source tree and applications.
168The support utilities used in the process of building RTEMS are
169described in @ref{RTEMS Specific Utilities}.  These are the
170only components of this subtree that will be discussed in this
171document.
172
173@end table
174
175
176
177@c
178@c  c/ Directions
179@c
180@section c/ Directory
181
182The @code{$@{RTEMS_ROOT@}/c/} directory was formerly
183the root directory of all RTEMS source code.  At this time, it contains
184the root directory for only those RTEMS components
185which must be compiled or linked in a way that is specific to a
186particular CPU model or board.  This directory contains the
187following subdirectories:
188
189@table @code
190@item $@{RTEMS_ROOT@}/c/src/
191This directory is logically the root for the RTEMS components
192which are CPU model or board dependent.  Thus this directory
193is the root for the BSPs and the Ada Test Suites as well
194as CPU model and BSP dependent libraries.  The contents of
195this directory are discussed in the
196@ref{Directory Structure c/src/ Directory} section.
197@end table
198
199@c
200@c c/src/ Directory
201@c
202@subsection c/src/ Directory
203
204As mentioned previously, this directory is logically
205the root for the RTEMS components
206which are CPU model or board dependent.  The
207following is a list of the subdirectories in this
208directory and a description of each.
209
210@table @code
211@item $@{RTEMS_ROOT@}/c/src/aclocal/
212This directory contains the custom M4 macros which are available to
213the various GNU autoconf @code{configure.ac} scripts throughout
214this portion of the RTEMS source tree.  GNU autoconf interprets
215@code{configure.ac} files to produce the @code{configure} files used
216to tailor RTEMS build for a particular host and target environment.  The
217contents of this directory will not be discussed further in this
218document.
219
220@item $@{RTEMS_ROOT@}/c/src/ada/
221This directory contains the Ada95 language bindings to the
222RTEMS Classic API.
223
224@item $@{RTEMS_ROOT@}/c/src/ada-tests/
225This directory contains the test suite for the Ada
226language bindings to the Classic API.
227
228@item $@{RTEMS_ROOT@}/c/src/automake/
229This directory contains files which are "Makefile fragments."
230They are included as required by the various @code{Makefile.am}
231files throughout this portion of the RTEMS source tree.
232
233@item $@{RTEMS_ROOT@}/c/src/lib/
234This directory contains the directories @code{libbsp/}
235and @code{libcpu/} which contain the source code for
236the Board Support Packages (BSPs) and CPU Model
237specific source code for RTEMS. 
238
239The @code{libbsp/} is organized based upon the CPU
240family and boards BSPs.  The contents of @code{libbsp/}
241are discussed briefly in
242@ref{Directory Structure c/src/lib/libbsp BSP Directory}
243and presented in detail in the
244@b{RTEMS BSP and Device Driver Development Guide}.
245
246The @code{libcpu/} directory is also organized by
247CPU family with further divisions based upon CPU
248model and features that are shared across CPU models
249such as caching and DMA.
250
251@item $@{RTEMS_ROOT@}/c/src/libchip/
252This directory contains device drivers for various
253peripheral chips which are designed to be CPU and
254board dependent.  This directory contains a variety
255of drivers for serial devices, network interface
256controllers, shared memory and real-time clocks.
257
258@item $@{RTEMS_ROOT@}/c/src/librtems++/
259This directory contains C++ classes which map to the RTEMS
260Classic API.
261
262@item $@{RTEMS_ROOT@}/c/src/make/
263This directory is used to generate the bulk of the supporting
264rules files which are installed as part of the Application Makefiles.
265This file contains settings for various Makefile variables to
266tailor them to the particular CPU model and BSP configured.
267
268@item $@{RTEMS_ROOT@}/c/src/nfsclient/
269This directory contains a Network File System (NFS) client
270for RTEMS.  With this file system, a user's application can
271access files on a remote computer.
272
273@item $@{RTEMS_ROOT@}/c/src/optman/
274This directory contains stubs for the RTEMS Classic API
275Managers which are considered optional and whose use
276may be explicitly forbidden by an application.  All of the
277directive implementations in this Optional Managers
278return @code{E_NOTCONFIGURED}.
279
280@item $@{RTEMS_ROOT@}/c/src/support/
281This directory exists solely to generate the RTEMS
282version string which includes the RTEMS version,
283CPU architecture, CPU model, and BSP name.
284
285@item $@{RTEMS_ROOT@}/c/src/wrapup/
286This directory is responsible for taking the individual
287libraries and objects built in each of the components
288in the RTEMS source tree and bundling them together to form
289the single RTEMS library @code{librtemsbsp.a}.  This
290library contains all BSP and CPU model specific software.
291
292@end table
293
294@c
295@c  c/src/lib/libbsp BSP Directory
296@c
297
298@subsubsection c/src/lib/libbsp BSP Directory
299
300The "libbsp" directory contains a directory for each CPU family supported
301by RTEMS.  Beneath each CPU directory is a directory for each BSP for that
302processor family.
303
304@c
305@c  Tree 7 - C BSP Library
306@c
307
308The "libbsp" directory provides all the BSPs provided with this
309release of the RTEMS executive.  The subdirectories are
310divided,  as discussed previously, based on specific processor
311family, then further broken down into specific target board
312environments.  The "no_cpu" subdirectory provides a starting point
313template BSP which can be used to develop a specific BSP for an
314unsupported target board.  The files in this subdirectory may aid
315in preliminary testing of the RTEMS development environment that has
316been built for no particular target in mind.
317
318Below each CPU dependent directory is a directory for each target BSP
319supported in this release.
320
321Each BSP provides the modules which comprise an RTEMS BSP.  The
322modules are separated into the subdirectories "clock", "console",
323"include", "shmsupp", "startup", and "timer" as shown in the following
324figure:
325
326@c
327@c  Tree 8 - Each BSP
328@c
329
330@c @ifset use-ascii
331@example
332@group
333                           Each BSP
334                               |
335  +-----------+----------+-----+-----+----------+----------+
336  |           |          |           |          |          |
337clock      console    include     shmsupp    startup     timer
338@end group
339@end example
340@c @end ifset
341
342@c
343@c  CPU Kit Directory
344@c
345@section CPU Kit Directory
346
347@c The @code{cpukit/} directory structure is as follows:
348
349@c
350@c  CPU Kit Tree
351@c
352
353@c @ifset use-ascii
354@c @example
355@c @group
356@c                        cpukit
357@c                          |
358@c   +-----------+----------+-----------+----------+
359@c   |           |          |           |          |
360@c posix       rtems       sapi       score     wrapup
361@c @end group
362@c @end example
363@c @end ifset
364
365The @code{cpukit/} directory contains a set of subdirectories which
366contains the source files comprising the executive portion of
367the RTEMS development environment as well as portable support
368libraries such as support for the C Library and filesystems.
369The API specific and "SuperCore" (e.g. @code{score/} directory)
370source code files are separated into distinct directory trees.
371
372The following is a description of each of the subdirectories
373under @code{cpukit/}:
374
375@table @code
376
377@item $@{RTEMS_ROOT@}/cpukit/aclocal/
378This directory contains the custom M4 macros which are available to
379the various GNU autoconf @code{configure.ac} scripts throughout
380the CPU Kit portion of the RTEMS source tree.
381GNU autoconf interprets @code{configure.ac}
382files to produce the @code{configure} files used to tailor
383RTEMS build for a particular host and target environment.  The
384contents of this directory will not be discussed further in this
385document.
386
387@item $@{RTEMS_ROOT@}/cpukit/automake/
388This directory contains files which are "Makefile fragments."
389They are included as required by the various @code{Makefile.am}
390files throughout the CPU Kit portion of the RTEMS source tree.
391
392@item $@{RTEMS_ROOT@}/cpukit/ftpd/
393This directory contains the RTEMS ftpd server.
394
395@item $@{RTEMS_ROOT@}/cpukit/httpd/
396This directory contains the port of the GoAhead
397web server to RTEMS.
398
399@item $@{RTEMS_ROOT@}/cpukit/include/
400This directory contains header files which are private to
401RTEMS and not considered to be owned by any other component
402in the CPU Kit.
403
404@item $@{RTEMS_ROOT@}/cpukit/libblock/
405This directory contains support code for using
406Block Devices such as hard drives, floppies, and
407CD-ROMs.  It includes the generic IO primitives
408for block device drivers, disk caching support,
409and a RAM disk block device driver.
410
411@item $@{RTEMS_ROOT@}/cpukit/libcsupport/
412This directory contains the RTEMS specific support routines
413for the Newlib C Library.  This includes what are referred
414to as system calls and found in section 2 of the traditional
415UNIX manual.   In addition, it contains a thread-safe
416implementation of the Malloc family of routines as well
417as BSD and POSIX services not found in Newlib.
418
419@item $@{RTEMS_ROOT@}/cpukit/libfs/
420This directory contains the various non-networked
421filesystem implementations for RTEMS.  It includes
422the In-Memory FileSystem (IMFS), the mini-IMFS,
423and FAT filesystems.
424
425@item $@{RTEMS_ROOT@}/cpukit/libi2c/
426This directory contains the RTEMS I2C framework.
427
428@item $@{RTEMS_ROOT@}/cpukit/libmd/
429This directory contains a port of the standard MD5
430checksum code.
431
432@item $@{RTEMS_ROOT@}/c/src/libmisc/
433This directory contains support facilities which
434are RTEMS specific but otherwise unclassified.  In
435general, they do not adhere to a standard API. 
436Among the support facilities in this directory are
437a @code{/dev/null} device driver, the Stack
438Overflow Checker, a mini-shell, the CPU and
439rate monotonic period usage monitoring libraries,
440and a utility to "dump a buffer" in a nicely
441formatted way similar to many ROM monitors.
442
443@item $@{RTEMS_ROOT@}/cpukit/libnetworking/
444This directory contains the port of the FreeBSD
445TCP/IP stack to RTEMS.
446
447@item $@{RTEMS_ROOT@}/cpukit/librpc/
448This directory contains the port of the FreeBSD
449RPC/XDR source to RTEMS.
450
451@item $@{RTEMS_ROOT@}/cpukit/libpci/
452This directory contains RTEMS PCI Library.
453
454@item $@{RTEMS_ROOT@}/cpukit/posix/
455This directory contains the RTEMS implementation
456of the threading portions of the POSIX API. 
457
458@item $@{RTEMS_ROOT@}/cpukit/pppd/
459This directory contains a port of the free implementation
460of the PPPD network protocol.
461
462@item $@{RTEMS_ROOT@}/cpukit/rtems/
463This directory contains the implementation of the
464Classic API.
465
466@item $@{RTEMS_ROOT@}/cpukit/sapi/
467This directory contains the implementation of RTEMS
468services which are required but beyond the realm
469of any standardization efforts.  It includes
470initialization, shutdown, and IO services.
471
472@item $@{RTEMS_ROOT@}/cpukit/score/
473This directory contains the "SuperCore" of RTEMS.
474All APIs are implemented in terms of SuperCore services.
475For example, Classic API tasks and POSIX threads
476are all implemented in terms of SuperCore threads.
477This provides a common infrastructure and a high degree
478of interoperability between the APIs.  For example,
479services from all APIs may be used by any task/thread
480independent of the API used to create it.
481
482Within the @code{score/} directory the CPU dependent modules are found.
483The @code{score/cpu/} subdirectory contains a subdirectory for each
484target CPU supported by this release of the RTEMS
485executive.  Each processor directory contains the CPU dependent
486code necessary to host RTEMS.  The @code{no_cpu} directory provides a
487starting point for developing a new port to an unsupported
488processor.  The files contained within the @code{no_cpu} directory
489may also be used as a reference for the other ports to specific
490processors.
491
492@item $@{RTEMS_ROOT@}/cpukit/shttpd/
493This directory contains the port of the Simple HTTPD
494web server to RTEMS.
495
496@item $@{RTEMS_ROOT@}/cpukit/telnetd/
497This directory contains the RTEMS telnetd server.
498
499@item $@{RTEMS_ROOT@}/cpukit/wrapup/
500This directory is responsible for taking the individual
501libraries and objects built in each of the components
502in the RTEMS CPU Kit source tree and bundling them
503together to form the single RTEMS library @code{librtemscpu.a}.  This
504library contains all BSP and CPU model specific software.
505
506@item $@{RTEMS_ROOT@}/cpukit/zlib/
507This directory contains a port of the GNU Zlib compression
508library to RTEMS.
509
510@end table
511
512@c
513@c  testsuites/ Test Suites
514@c
515@section testsuites/ Test Suites
516
517This directory provides all of the RTEMS Test Suite
518except those for the Classic API Ada95 binding
519This includes the single processor tests, multiprocessor tests,
520timing tests, library tests, and sample tests.   Additionally,
521subdirectories for support functions and test related header
522files are provided.  The following table lists the test suites
523currently included with the RTEMS and the directory in which
524they may be located:
525
526@table @code
527
528@item $@{RTEMS_ROOT@}/testsuites/libtests/
529This directory contains the test suite for the
530various RTEMS support components.
531
532@item $@{RTEMS_ROOT@}/testsuites/mptests/
533This directory contains the test suite for the
534multiprocessor support in the Classic API.
535The tests provided address two node configurations
536and provide coverage for the multiprocessor code found
537in RTEMS.
538
539@item $@{RTEMS_ROOT@}/testsuites/psxtests/
540This directory contains the test suite for the
541RTEMS POSIX API.
542
543@item $@{RTEMS_ROOT@}/testsuites/samples/
544This directory provides sample application tests
545which aid in the testing a newly built RTEMS environment, a new
546BSP, or as starting points for the development of an application
547using the RTEMS executive.  They are discussed in
548@ref{Sample Applications}.
549
550@item $@{RTEMS_ROOT@}/testsuites/sptests/
551This directory contains the test suite for the RTEMS
552Classic API when executing on a single processor.
553The tests were originally designed to provide
554near complete test coverage for the entire
555executive code.  With the addition of multiple APIs,
556this is no longer the case as some SuperCore functionality
557is not available through the Classic API.  Thus
558some functionality in the SuperCore is only covered
559by tests in the POSIX API Test Suites.
560
561@item $@{RTEMS_ROOT@}/testsuites/support/
562This directory contains support software and header files
563for the various test suites.
564
565@item $@{RTEMS_ROOT@}/testsuites/tmtests/
566This directory contains the timing test suite for
567the RTEMS Classic API.  This include tests that
568benchmark each directive in the Classic API
569as well as a set of critical SuperCore functions.
570These tests are important for helping to verify
571that RTEMS performs as expected on your target hardware.
572It is not uncommon to discover mistakes in board
573initialization such as caching being disabled as
574a side-effect of analyzing the results of these tests.
575
576@item $@{RTEMS_ROOT@}/testsuites/tools/
577This directory contains tools which execute on
578the development host and aid in executing and
579evaluating the results of the test suite.  The
580tools @code{difftest} compares the output of one
581or more tests with the expected output.  If you
582place the output of all the @code{tmtests/} in
583a single file, then the utility @code{sorttimes}
584will be able to produce a report organizing the
585execution times by manager.
586
587@end table
588
589
590@c
591@c  Documentation Directory
592@c
593@section Documentation Directory
594
595This directory contains the source code for all RTEMS documentation
596in @code{TexInfo} format as well as utilities used in the generation
597of the RTEMS documentation set.  This source code is used to produce
598the RTEMS documentation in various formats including PDF, HTML,
599and PostScript.
600
601@table @code
602
603@item $@{RTEMS_ROOT@}/doc/ada_user/
604This directory contains the source code for the @cite{RTEMS
605Applications Ada User's Guide} which documents the Ada95
606binding to the Classic API.  This manual is produced from
607from the same source base as the @cite{RTEMS Application
608C User's Guide}.
609
610@item $@{RTEMS_ROOT@}/doc/bsp_howto/
611This directory contains the source code for the
612@cite{RTEMS BSP and Device Driver Development Guide}.
613
614@item $@{RTEMS_ROOT@}/doc/common/
615This directory contains the source code for the files which
616are shared across multiple manuals in the RTEMS Documentation Set.
617This includes the copyright page as well as the timing
618tables which can be filled in on a per BSP basis in the
619CPU supplements.
620
621@item $@{RTEMS_ROOT@}/doc/cpu_supplement/
622This directory contains the source code for the
623RTEMS CPU Supplement.
624
625@item $@{RTEMS_ROOT@}/doc/develenv/
626This directory contains the source code for the
627@cite{RTEMS Development Environment Guide}.  This is
628the document you are currently reading.
629
630@item $@{RTEMS_ROOT@}/doc/filesystem/
631This directory contains the source code for the
632@cite{RTEMS Filesystem Design Guide}.  This manual
633is a continuous work in process as it attempts to
634capture the design of the interface between system
635calls and filesystem implementations as well as the
636information required by those implementing filesystems.
637
638@item $@{RTEMS_ROOT@}/doc/images/
639This directory contains the source code for the graphics
640used in the HTML version of the RTEMS Documentation.
641
642@item $@{RTEMS_ROOT@}/doc/networking/
643This directory contains the source code for the
644@cite{RTEMS Network Supplement}. 
645
646@item $@{RTEMS_ROOT@}/doc/new_chapters/
647This directory contains the source code for the new documentation
648components which have not yet been collected into a new manual or
649merged into an existing document.  Currently, this primarily
650contains draft documentation for some portions of
651the facilities implemented in @code{$@{RTEMS_ROOT@}/c/src/libmisc/}.
652
653@item $@{RTEMS_ROOT@}/doc/porting/
654This directory contains the source code for the
655@cite{RTEMS Porting Guide}.
656
657@item $@{RTEMS_ROOT@}/doc/posix1003.1/
658This directory contains the source code for the
659@cite{RTEMS POSIX 1003.1 Compliance Guide}.
660
661@item $@{RTEMS_ROOT@}/doc/posix_users/
662This directory contains the source code for the
663@cite{RTEMS POSIX API User's Guide}.  It is important to
664note that RTEMS' support for POSIX is a combination of
665functionality provided by RTEMS and the Newlib C Library
666so some functionality is documented by Newlib.
667
668@item $@{RTEMS_ROOT@}/doc/relnotes/
669This directory contains the source code for a formally
670release notes document.  This has not been used for
671recent RTEMS releases.
672
673@item $@{RTEMS_ROOT@}/doc/started/
674This directory contains the source code for the
675@cite{Getting Started with RTEMS for C/C++ Users} manual.
676
677@item $@{RTEMS_ROOT@}/doc/tools/
678This directory contains the source code for the tools
679used on the development host to assist in producing the
680RTEMS Documentation.  The most important of these tools
681is @code{bmenu} which generates the hierarchical node
682linking commands based upon chapter, section, and
683subsection organization.
684
685@item $@{RTEMS_ROOT@}/doc/user/
686This directory contains the source code for the @cite{RTEMS
687Applications C User's Guide} which documents the Classic API.
688
689@end table
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