On Fri, Apr 2, 2021 at 12:19 PM Ayushman Mishra <ayushvidush...@gmail.com> wrote: > > --- > user/bld/index.rst | 2 + > user/overview/index.rst | 2 + > user/start/faq.rst | 295 +++++++++++++++++++++++++++++++ > user/start/index.rst | 1 + > user/support/contrib.rst | 96 +--------- > user/support/support-project.rst | 2 + > 6 files changed, 303 insertions(+), 95 deletions(-) > create mode 100644 user/start/faq.rst > > diff --git a/user/bld/index.rst b/user/bld/index.rst > index ebedf5a..0cccde2 100644 > --- a/user/bld/index.rst > +++ b/user/bld/index.rst > @@ -284,6 +284,8 @@ example configuration file, building of the tests is > enabled for the > > [riscv/griscv] > > +.. _Migration_from_AutoconfAutomake: > + > Migration from Autoconf/Automake > ================================ > > diff --git a/user/overview/index.rst b/user/overview/index.rst > index 550724a..0703ede 100644 > --- a/user/overview/index.rst > +++ b/user/overview/index.rst > @@ -20,6 +20,8 @@ You are someone looking for a real-time operating system. > This document > > - helps you to build an example application on top of RTEMS. > > +.. _Features: > + > Features > ======== > > diff --git a/user/start/faq.rst b/user/start/faq.rst > new file mode 100644 > index 0000000..910ef8b > --- /dev/null > +++ b/user/start/faq.rst > @@ -0,0 +1,295 @@ > +Frequently Asked Questions > +========================== > + > +What is RTEMS ? No whitespace before punctuation. "What is RTEMS?"
> +----------------------------------- > + > +RTEMS is an open source real-time executive which provides a high performance > +environment for embedded real-time applications including many features. > + > +The RTEMS Project is the umbrella term used to describe the collection of > +individuals, companies, universities, and research institutions that > collectively > +maintain and enhance the RTEMS software base. > + > +RTEMS is designed to support applications with the most stringent real-time > +requirements while being compatible with open standards such as POSIX. > +RTEMS includes optional functional features such as TCP/IP and various file > +systems while still offering minimum executable sizes under 20 KB in useful > +configurations. > + > +:ref:`More Features<Features>` > + > +Where can I get RTEMS ? > +----------------------------------------------------------------- > + > +:ref:`Downloading RTEMS<QuickStartSources_Released>` > + What happened to: How can I pronounce RTEMS like Joel? > +What does RTEMS stand for ? > +------------------------------------------------- > + > +RTEMS is an an acronym for the Real-Time Executive for Multiprocessor > Systems. "an an" (typo in original wiki page :) > + > +Initially RTEMS stood for the Real-Time Executive for Missile Systems but as > it > +became clear that the application domains that could use RTEMS extended far > +beyond missiles, the "M" changed to mean Military. When maintenance of RTEMS > +transferred to OAR, the "M" was changed again to Multiprocessor. > + > +At one point, there were both Ada and C implementations of RTEMS. > +Version 3.2.1 was the last RTEMS version to have implementations in both > +languages. Supporting the Classic API Ada implementation was painful and > fraught > +with compiler specific pitfalls. With version 3.5.x, the POSIX API was added > as > +the means to support the GNU Ada Translator (GNAT). This effectively > eliminated > +the need for an implementation in Ada as the C implementation could > effectively > +support both languages. > + > +Are there restrictions on the RTEMS License ? > +-------------------------------------------- > + > +RTEMS RTEMS is licensed under a combination of permissive licenses and a > +modified version of the GNU General Public License (GPL). > +For source code "Two Clause BSD” (BSD-2-Clause) and > +for documentation CC-BY-SA-4.0 license is preferred. > +The modification places no restrictions on the applications which use RTEMS > but > +protects the interests of those who work on RTEMS. > + > +`License in RTEMS > +<https://docs.rtems.org/branches/master/eng/ > +license-requirements.html>`__ > + add the other questions even if their pages are missing, and maybe add a "TBD" stub or something so someone can provide the answers. Here would be "Are there Export Restrictions? on RTEMS?" > +What standards are supported by RTEMS? > +--------------------------------------------------------- > + > +The original "Classic" RTEMS API is based on the Real-Time Executive > Interface > +Definition (RTEID) and the Open Real-Time Kernel Interface Definition > (ORKID). > +RTEMS also includes support for POSIX threads and real-time extensions. > + > +With the addition of file system infrastructure, RTEMS supports approximately > +80% of the POSIX 1003.1b-1996 standard. This standard defines the programming > +interfaces of standard UNIX. This means that much source code that works on > +UNIX, also works on RTEMS.RTEMS includes a port of the FreeBSD TCP/IP stack > and > +thus supports BSD sockets. It also includes support for numerous networking > +clients (DHCP, TFTP, NFS, etc.) and servers (FTPD, HTTPD, etc.). > + > +What processors is RTEMS available for ? > +---------------------------------------------------------- > + > +:ref:`Architectures in RTEMS<TargetArchitectures>` Make this read as a complete sentence: See :ref:`Architectures in RTEMS<TargetArchitectures>`. > + > +Are there similar commercial products ? > +-------------------------------------------- > + > +`Some Real time operating system similar to RTEMS > +<https://en.wikipedia.org/wiki/Comparison_of_real-time_operating_systems>`__ > + > +How can I obtain RTEMS support ? > +----------------------------------------------------- > + > +:ref:`Support in RTEMS<RTEMS_Project_Support>` > + > +What RTEMS Training Opportunities are available ? > +-------------------------------------------------- > + > +`RTEMS Training Opportunities > <https://www.rtems.org/TrainingOpportunities>`__ ditto > + > +How can I contribute? > +------------------------------------------- > + > +:ref:`Contributions in RTEMS<Contributing>` ditto > + > +How are floating point numbers handled ? > +--------------------------------------------- > + > +`Floating point support in RTEMS > +<https://docs.rtems.org/branches/master/c-user/task/ > +background.html#floating-point-considerations>`__ ditto > + > +How do I make a patch ? > +-------------------------- > + > +`Creating and sending patch in RTEMS > +<https://docs.rtems.org/branches/master/eng/vc-users.html#creating-a-patch>`__ > + > +Why is my executable so big? > +------------------------------------------------------- > + > +There are two primary causes for this. The most common is that you are doing > an > +ls -l and looking at the actual file size – not the size of the code in the > +target image. This file could be in an object format such as ELF or COFF and > +contain debug information. If this is the case, it could be an order of > magnitude > +larger than the required code space. Use the strip command in your cross > +toolset to remove debugging information. > + > +Another alternative is that the executable file is in an ASCII format such as > +Motorola Srecords. In this case, there is no debug information in the file > +but each byte in the target image requires two bytes to represent. On top of > +that, there is some overhead required to specify the addresses where the > image > +is to be placed in target memory as well as checksum information. In this > +case, it is not uncommon to see executable files that are between two and > three > +times larger than the actual space required in target memory. > + > +Remember, the debugging information is required to do symbolic debugging > with gdb. > +Normally gdb obtains its symbolic information from the same file that it gets > +the exe- cutable image from. However, gdb does not require that the > executable > +image and symbolic information be obtained from the same file. So you might > want > +to create a hello_with_ symbols.exe, copy that file to > hello_without_symbols.exe, > +and strip hello_without_ symbols.exe. Then gdb would have to be told to read > +symbol information from hello_ with_symbols.exe. The gdb command line option > +-symbols or command symbol-file may be used to specify the file read for > +symbolic information > + > +What MinGW Tools for Windows are available ? > +------------------------------------------------------------------------- > + > +Windows users can use MinGW based RTEMS tools. These tools will generate the > +same application code for RTEMS as the tools on Linux or Cygwin. MinGW tools > +use the native Windows runtime rather than access Windows via the POSIX > interfac > +Cygwin provides. MinGW tools are faster than the Cygwin equivalent and are > not > +confused by Cygwin mount points. Compiler errors will show a Windows path > rather > +than a Cygwin path and so do not confuse native Windows editors. > +:ref:`Cygwin in windows<Cygwin>` > + > +The RTEMS MinGW Tools are not currently packaged in installers. The > installers > +stopped around RTEMS 4.9 when the MinGW tools started to be built as part of > +the binary tool package. This means you need to manually step through the > +process. It is not difficult, how-ever it is not an easy installer. > + > +What is Multilib RTEMS ? > +----------------------------------------------------------------- > + > +The multilib process supports building a set of related libraries for a given > +target where the individual libraries in the set use different specific > +compiler flags (such as flags for code generation options, pre-processor > +defines, etc) for the individual libraries. The reason this is needed can be > +seen by examining the M68K GCC compiler. That compiler generates code for a > +number of processor variants in the M68K family, for example, it can generate > +code for the original 68000, the 68040 or a 528x Coldfire. These processors > all > +use a closely related instruction set, but processor differences mean code > +compiled for one may not run on another. GCC provides a special library > called > +libgcc.a that holds intrinsic functions needed by the compiler. These > +intrinsic functions provide "software instructions" (such as non-basic math > +support routines) that the processor may not support. However, which > functions > +GCC considers to be intrinsic should be able to vary within a processor > family. > +One processor variant will have hardware floating point and another processor > +variant will not, and GCC (and RTEMS) should be able to generate efficient > code > +for each processor variant. When we wish to have different code for a range > of > +related yet potentially incompatible processors in a family by providing > +multiple related libraries we use the multilib process. > + > +The multilib process extends beyond libgcc.a to libc.a, libm.a, and > libstd++.a. > +An RTEMS tool set will provide each of these libraries for each of the > processor > +variants that GCC supports. You can see the multilib information by invoking > gcc > +with the option '-print-multi-lib'. The output for the M68K tool chain is - > + > +.. code-block:: none > + > + $ m68k-rtems-gcc -print-multi-lib .; m68000;@m68000 m5200;@m5200 > + m5206e;@m5206e m528x;@m528x m5307;@m5307 m5407;@m5407 mcpu32;@mcpu32 > + m68040;@m68040 m68060;@m68060 msoft-float;@msoft-float > + > +This output is not easy to read as it is designed for other tools or > packages. > + > +RTEMS core under the cpukit source tree does not reference any BSP specific > +details. This allows it to be built as a set of multiple libraries named > +librtemscpu.a. A configure command line option will build a multilib RTEMS as > +shown in Building a CPU Kit. > + > +BSP and CPU model specific portions of RTEMS (libcpu and libbsp) are > +built into the separate library librtemsbsp.a. > + > +What is the difference between the workspace and heap ? > +---------------------------------------------------------------------- > + > +The RTEMS Workspace is used to allocate space for objects created by RTEMS > +such as tasks, semaphores, message queues, etc.. It is primarily used during > +system initialization although task stacks and message buffer areas are also > +allocated from here. > + > +Why should we work with the RTEMS developers ? > +--------------------------------------------------------------------------- > + > +Our engineers understand our target environment better than anyone else, and > +we have a tight schedule. Why should we work with the RTEMS developers, when > +we can get the code out faster by whacking it out on our own? > + > +You understand your target environment better than anyone else. > +However, the RTEMS developers understand RTEMS better than anyone > +else; furthermore, the RTEMS developers tend to have a wide breadth > +of experience across a large number of processors, boards, peripherals, > +and application domains. It has been our experience that few problems > +encountered in embedded systems development are unique to a particular > +processor or application. The vast majority of the time an issue that > +arises in one project has also shown up in other projects. > + > +The intimate knowledge of RTEMS internals as well as a wide breadth of > +embedded systems knowledge means that there is a good chance that at > +least one RTEMS developer has already addressed issues you are likely > +to face when doing your port, BSP, or application. The developers can > +help guide you towards a workable long term solution, possibly saving > +you significant time in your development cycle. > + > +If getting the sources into the official RTEMS distributions is one of > +your goals, then engaging other RTEMS developers early will also likely > +shorten your development time. By interacting as early as possible you > +are more likely to write code which can be easily accepted into the official > +sources when you are finished. If you wait until you think you are done > +to begin interacting with the RTEMS team, you might find that you did > +some things wrong and you may have to rewrite parts of your RTEMS port, > +which is a waste of your valuable time. > + > +Why should we integrate our port into the official RTEMS sources? > +------------------------------------------------------------------ > + > +Why should we care if our port is integrated into the official RTEMS sources? > +We can distribute it ourselves to whoever is interested. > + > +Yes, the RTEMS licenses allows you to do that. But by doing so, you end up > +having to maintain that code yourself; this can be a significant > +effort over time as the RTEMS sources change rapidly. > + > +You also lose the advantage of wider exposure by including your port > +in the official RTEMS sources maintained by the RTEMS Project. > +The wider exposure in the RTEMS developer and tester community will > +help keep your work up to date with the current sources. You may even > +find that volunteers will run the ever-growing test suite on your port > +and fix problems during the development cycle -- sometimes without your > +intervention. > + > +It has been our experience that integrated ports tend to ultimately > +be of better quality and stay up to date from release to release. > + > +Aspects of my target environment that my application exploits are still > under NDA > +--------------------------------------------------------------------------------- > + > +Nevertheless, if the target hardware is built of any commercial parts > +that are generally available including, but not limited to, the CPU > +or peripherals, then that portion of your work is still of general use. > +Similarly, if you have written software that adheres to existing API or > +interface standards, then that portion is also of general use. > +Our experience is that most embedded applications do utilize a custom > +mix of hardware and application, but they are built upon layers of hardware > +and software components that are in no way unique to the project. > + > +If you are porting to an unreleased CPU family or model, then just > +announcing it is important because other RTEMS users may be planning > +to use it and some of them may already be trying to port RTEMS on > +their own. Your customers might be happier to know that your port > +will eventually be available. Also, there is no requirement that RTEMS > +include all features or ports at any particular time, so you are encouraged > +to submit discrete pieces of functionality in stages. > + > +Assume that your processor has some new functionality or peripherals. > +However that functionality is still covered by NDA, but the basic core > +architecture is not. It is still to your advantage to go ahead and work > +with the developers early to provide a "base port" for the CPU family. > +That base port would only use the publicly available specifications > +until such time as the NDA is lifted. Once the NDA is lifted you can > +work with the developers to provide the code necessary to take > +advantage of the new functionality. > + > +What is the difference between autoconf and waf build system ? > +-------------------------------------------------------------- > + > +Waf is a build automation tool written in Python which is designed to assist > +in the automatic compilation and installation of computer software. > +:ref:`Converting from Autoconf/Automake to waf build system > +<Migration_from_AutoconfAutomake>` > diff --git a/user/start/index.rst b/user/start/index.rst > index 17c34e1..e178209 100644 > --- a/user/start/index.rst > +++ b/user/start/index.rst > @@ -23,3 +23,4 @@ applications on top of RTEMS. > app > rsb-packages > gsoc > + faq > diff --git a/user/support/contrib.rst b/user/support/contrib.rst > index c42d41b..758f0f6 100644 > --- a/user/support/contrib.rst > +++ b/user/support/contrib.rst > @@ -168,98 +168,4 @@ time, or have proven very hard to integrate. So, what we > are asking > is that, to the maximum extent possible, you communicate with us > as early on and as much as possible. > > -Common Questions and Answers > -============================ > - > -Here are some questions RTEMS porters may have with our answers to > -them. While the focus here is on new ports and BSPs, we believe that > -the issues are similar for other RTEMS development efforts including > -student efforts to implement new algorithmic optimizations. > - > - Our engineers understand our target environment better than anyone else, > and > - we have a tight schedule. Why should we work with the RTEMS developers, > when > - we can get the code out faster by whacking it out on our own? > - > -You understand your target environment better than anyone else. > -However, the RTEMS developers understand RTEMS better than anyone > -else; furthermore, the RTEMS developers tend to have a wide breadth > -of experience across a large number of processors, boards, peripherals, > -and application domains. It has been our experience that few problems > -encountered in embedded systems development are unique to a particular > -processor or application. The vast majority of the time an issue that > -arises in one project has also shown up in other projects. > - > -The intimate knowledge of RTEMS internals as well as a wide breadth of > -embedded systems knowledge means that there is a good chance that at > -least one RTEMS developer has already addressed issues you are likely > -to face when doing your port, BSP, or application. The developers can > -help guide you towards a workable long term solution, possibly saving > -you significant time in your development cycle. > - > -If getting the sources into the official RTEMS distributions is one of > -your goals, then engaging other RTEMS developers early will also likely > -shorten your development time. By interacting as early as possible you > -are more likely to write code which can be easily accepted into the official > -sources when you are finished. If you wait until you think you are done > -to begin interacting with the RTEMS team, you might find that you did > -some things wrong and you may have to rewrite parts of your RTEMS port, > -which is a waste of your valuable time. > - > - Why should we care if our port is integrated into the official RTEMS > - sources? We can distribute it ourselves to whoever is interested. > - > -Yes, the RTEMS licenses allows you to do that. But by doing so, you end up > -having to maintain that code yourself; this can be a significant > -effort over time as the RTEMS sources change rapidly. > - > -You also lose the advantage of wider exposure by including your port > -in the official RTEMS sources maintained by the RTEMS Project. > -The wider exposure in the RTEMS developer and tester community will > -help keep your work up to date with the current sources. You may even > -find that volunteers will run the ever-growing test suite on your port > -and fix problems during the development cycle -- sometimes without your > -intervention. > - > -It has been our experience that integrated ports tend to ultimately > -be of better quality and stay up to date from release to release. > - > - Why should we communicate up front? We are happy to let the RTEMS > developers > - integrate our stuff later. > - > -See above. It will save work for you over both the short and the > -long term, and it is the right thing to do. > - > - Aspects of my target environment that my application exploits are still > - under NDA. > - > -Nevertheless, if the target hardware is built of any commercial parts > -that are generally available including, but not limited to, the CPU > -or peripherals, then that portion of your work is still of general use. > -Similarly, if you have written software that adheres to existing API or > -interface standards, then that portion is also of general use. > -Our experience is that most embedded applications do utilize a custom > -mix of hardware and application, but they are built upon layers of hardware > -and software components that are in no way unique to the project. > - > -If you are porting to an unreleased CPU family or model, then just > -announcing it is important because other RTEMS users may be planning > -to use it and some of them may already be trying to port RTEMS on > -their own. Your customers might be happier to know that your port > -will eventually be available. Also, there is no requirement that RTEMS > -include all features or ports at any particular time, so you are encouraged > -to submit discrete pieces of functionality in stages. > - > -Assume that your processor has some new functionality or peripherals. > -However that functionality is still covered by NDA, but the basic core > -architecture is not. It is still to your advantage to go ahead and work > -with the developers early to provide a "base port" for the CPU family. > -That base port would only use the publicly available specifications > -until such time as the NDA is lifted. Once the NDA is lifted you can > -work with the developers to provide the code necessary to take > -advantage of the new functionality. > - > -Ultimately, cooperating with the free software community as early as > -possible helps you by decreasing your development cycle, decreasing > -your long term maintenance costs and may help raise interest in your > -processor by having a free compiler implementation available to > -anyone who wants to take a look. > + don't add extra spaces randomly > diff --git a/user/support/support-project.rst > b/user/support/support-project.rst > index b782029..73d5851 100644 > --- a/user/support/support-project.rst > +++ b/user/support/support-project.rst > @@ -6,6 +6,8 @@ > > .. index:: support; RTEMS Project > > +.. _RTEMS_Project_Support: > + > RTEMS Project Support > ********************* > > -- > 2.25.1 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel