Is it possible to add a new architecture to gem5 library? If I can add, then what is the procedure to do so. And is there any documents which can help me. I just want to add POWER-PC architecture though it has power architecture in it.
I would just copy one of the better maintained existing ISAs (X86, ARM or RISCV seem to be the best maintained to me), mass find and replace old ISA to new ISA name in all files, and then start hacking it up to look like your ISA.
Basic userland syscall emulation is likely feasible for one person to achieve (depending on how well you know your ISA and gem5), but I suspect full system would be months of work.
Related
I wonder if is possible to have only precompiled modules or some sort of MoarVM bytecode.
The idea is to protect the source code at some grade - at least i don't want to be in plain text
Not at the moment. But the design of how CompUnit repositories work, makes that entirely possible. It's just that nobody has been willing to put in the work to make that happen. And it is on my (very long) todo list.
Apart from protecting source code (which may actually be a little more futile when the RakuAST branch lands), I was more thinking of the situation of running Raku on a very small processor with little memory (think RaspBerry and the like), which would make it nice if it would be able to load (binary) modules on demand over the network (without the source).
What are the differences between the different Rebol 3 branches, especially with the new REN branch?
Is it the platforms they'll run on, the feature set, code organization, the C standard compliance?
This is an answer destined to become outdated, hence set to Community Wiki. This information is as of Sep-2015. So if updating this answer after some time has passed, please modify the date as well.
Binary download of Rebol3 from rebol.com
Last build was 5-Mar-2011 and pre-dates the open source release.
No GUI support, no HTTPS support, no serial port support, no UDP support, no smart console...
No 64-bit builds. Binaries are for Windows x86, OS/X (PPC or x86), Linux (x86 or PPC), FreeBSD x86.
While Rebol2 binaries are archived for many "esoteric" systems (BeOS, AIX, Windows DEC Alpha, QNX, Solaris...) similar binaries were not provided for Rebol3. The only "weird" build is for Amiga, and only an OS4 PowerPC Amiga. No successful builds of Rebol3 for Amiga emulators have been reported.
Open source release of Rebol3 on Github rebol/rebol
Open-sourcing was on 12-Dec-2012.
The rebol.com binary downloads were not rebuilt as part of this release. However, a community member (#earl here on SO) created a build farm at rebolsource.net that follows this GitHub master whenever it updates. Given that GitHub's rebol/rebol master hasn't been updated since March 2014, this dynamism is currently underused.
Building the source at time of release got an executable not distinguishable (?) in functionality from the builds on 5-Mar-2011. This suggests few changes to the source were made besides some cleanup and Apache-licensing edits to prepare for publication.
Minor patches and bugfixes were integrated sporadically, with most PRs sitting idle. Last PR accepted at time of writing was Mar 3, 2014, which is over a year ago.
The most noticeable "breaking" PR that did get approved was to repurpose the FUNCTION name. It was considered to be worth breaking the old arity 3 form to let the word be taken for the much more useful implementation as locals-gathering FUNCT. (This also brought Rebol in alignment with Red, whose FUNCTION is arity 2 and acts similarly.) FUNCT was kept around as-is for legacy code.
The most major non-breaking PR that was taken is probably not requiring blocks around IF, UNLESS, or EITHER bodies. This has been received well among those who know it's there, as fitting the freeform and non-boilerplate philosophy of the language. It allows some code constructs to get "prettier" and gives programmers more choice, while it doesn't seem to cause any more problems than anything else. It's certainly less of a speedbump than if [condition] [...], in fact it seems almost no one knows this feature got added, so it must not be biting anyone. (If anyone can bend ears over at Red to make sure it gets IF and IF/ONLY then that would be ideal.)
RETURN/REDO was removed. Rationale was that it permitted functions to effectively behave with variable arity, and that this was unnecessary and took terra firma away by no longer being able to predict a function's arity from its spec. Perhaps this stance warrants a second look...as Lisp users who are pressuring for the addition of Lisp-style macros seeming aren't worried about that very much. (Here in the StackExchange universe, this provoked a Programmers.SE question Would Rebol (or Red) benefit from Lisp-style Macros?, which hasn't gotten much in the way of answers yet.)
The fork by Saphirion: "Saphir"
Prior to the open-sourcing of Rebol, Saphirion AG had a special relationship with Rebol technologies. They had access to the source and were taking responsibility for most of the development work for Rebol3 GUI features. They also added several other things like HTTPS.
Saphir is available as a binary download from their website, but only provided for 32-bit Windows. There was at one time an experimental .APK for Android from Saphirion.
Some (but not all) of Saphir's source was released after the open-sourcing. Notable omissions were the android build and some Rebol3 code for encapping...a way of injecting compressed scripts and resources into binaries of the interpreter without needing to recompile it.
(Note: Under Apache2 license there is no requirement to release source code for one's derived work.)
"Community" Integration at Rebolsource on GitHub
With the GitHub rebol/rebol being held up on integrations, a fork at rebolsource/r3 was established to be a "community build" where work could be staged.
Rebolsource changes were conservative, seemingly aimed toward showing process for how GitHub's rebol/rebol might adopt changes "in the spirit in which Rebol was conceived" should that repository be delegated to the community. (For that spirit, see this.) Hence it integrated non-controversial bugfixes and tweaks, instead of large third-party cryptography libraries for implementing HTTPS. Also: no allowance for adding build dependencies besides a C compiler (no GNU autotools, for instance).
Binaries for the community build were produced on an as-needed basis for those requesting them who could not build it themselves.
Atronix Engineering's Rebol "3.0" at Github zsx/r3
Atronix is an industrial automation solutions provider that uses Rebol. How they do so is described in a video here by David den Haring, director of Engineering, and their ZOE software is built on their version of Rebol.
After the open sourcing, Atronix partnered with Saphirion to port the GUI to Linux. Atronix publishes their source publicly as it is developed, and David den Haring notes in the video above that they have only one proprietary component they developed (an industrial control driver). Other than that they are happy to share the source for all Rebol development they do.
Atronix integrated the 64-bit patches from Rebolsource, created a Windows 64-bit target, and offer up-to-date binaries of their development branch for Windows and Linux x86/x64, as well as Linux ARMv7.
Besides having the features of Saphir, the Atronix build added support for CALL with /INPUT, /OUTPUT, /ERROR. It also added a Foreign Function Interface, implementing LIBRARY!, ROUTINE! and STRUCT! for communicating with non-Rebol dynamic libraries. It brings in encapping support as well on Windows and Linux.
Rebol's "religion" was at times at odds with expedience, so the Rebol-based build process was replaced when needed by hand-edited makefiles and Visual Studio projects. The FFI library introduced a dependency on GNU autotools to build.
All Atronix builds include the GUI, so there is no "Core" build. And again, only Linux and Windows.
Ren-C
(Bias Note: This fork is the initiative #HostileFork started, knows the most about, and will speak most enthusiastically about.)
Ren-C started as an an extraction of a Core build out of Atronix's codebase. That gave it features like HTTPS, the enhanced CALL, and Foreign Function Interface to essentially all the platforms that Rebolsource was able to build for. Updates Jul/Sep-2015 Ren/C supports line continuations in the console, user infix functions, several bugfixes...
Ren-C makes large-scale changes and fixes fundamental issues in R3-Alpha, which are tracked on a Trello that provides more information. There is a new FAQ as a GitHub wiki. Critical issues like definitionally-scoped returns have been solved, with continuous work on other outstanding problems.
Though Atronix's R3/View required some additional dependencies, Ren/C pushed back to being able to be built with nothing besides a C compiler, and eliminated all handmade makefiles/projects.
Beyond Windows, Linux and Mac in both 32-bit and 64-bit variants, Ren/C has also been built for smaller players like HaikuOS and yes, even Syllable. This is interesting more for the demonstration of how broadly turnkey builds of the C89 code work (simply as make -f makefile.boot) as opposed to there being a particularly large userbase of those particular OSes!
From the point of view of language rigor, Ren/C is pushing on modern techniques. Although it can still build as C89, it can be built as C99 and C11 as well. It has also been verified to build as C++98 through C++14, and with some strategic modifications under #ifdef __cplusplus it can take advantage of modern C++ as a kind of static analysis tool over the C code. Warnings are raised, type errors all fixed up, and it's "const correct". The necessary changes were carefully considered to make Rebol's baseline C code not just more correct but cleaner and clearer source across the board.
From a point of view of C developers, Ren/C should be stable, organized, and commented enough for anyone who knows C to "modify with confidence" and try new features. That means being able to implement definitionally scoped returns (actually written, but not pushed), or try developing features like NewPath.
From a point of view of architecture, Ren/C is intended to not have an executable at all...but to be a library for embedding a Rebol interpreter into other programs. It is now the basis for Ren/C++, which was designed to anticipate working with Red as well.
From a point of view of testing, Ren/C intends to whip everything into shape for engineering rigor and zero bug tolerance. This means avoiding practices like zero-filling memory to obscure uninitialized memory accesses, using Address Sanitizer, Valgrind, and a test suite that can pass the highest settings on both.
While enabling all the extra functionality has made Ren/C's executable nearly twice the size of Rebolsource's, there's not yet been any audit to see how this can be brought down. It has been confirmed that there are duplicate copies of Zlib and PNG encoding/decoding--for instance (Saphirion included LodePNG, likely to work around a bug in the existing PNG because it was easier than fixing it...yet did not mothball the previous code). Also, being able to do a build which selectively integrates only the codecs you want to use is on the agenda.
Ren/C currently has the stakeholders from Atronix and Rebolsource participating in its development and direction, which strengthens the likelihood that it may evolve into "the" Rebol Core. It is now being linked in as the code backing Ren Garden, and using a similar approach it may be set up as the library used by Atronix's R3/View...then Rebolsource...and perhaps ultimately rebol/rebol itself.
The fork by Oldes
(Bias Note: this edit is added 28-Feb-2019 by Oldes himself)
Forked from the community branch. Main focus on keeping the code close to the original Carl's release without blindly taking everything from Atronix/Saphirion but still trying to pick-up the good things from these branches slowly.
Not like Ren-C, this version is not trying to introduce new syntax, but rather be closer to the original Rebol2 and new Red language
We'd like to offer a compiled library that implement a protocol layer to be imported into C/C++ source code project for microcontrollers. And eventually expose a sort of compiled function to the source code project. let's say a sort of "dll". Is there any know technique to realize something of similar?
While it is possible to provide functions via a library, generally in the microcontroller/embedded realm it quickly becomes impractical.
Each microcontroller core will have a unique instruction set. Further, micros from the same family may have a variety of extensions which are either supported or not... So you're left with providing a library file for each individual microcontroller (from each vendor) that you'd like to support.
But...
In my experience, calling conventions between compilers are not the same. So a library compiled by one toolchain will not be able to be linked to object files created by another toolchain.
That leads you to then provide a library for each individual micro from each vendor for each toolchain someone might use. Ick. Oh, and don't rely on an OS calls either, as you don't know what you'll be linked with...
A more conventional approach is to use the same approach RTOS vendors tend to use: provide the source, and protect your IP with licensing terms. The reality is that if your end users want to, they can step through the assembly and figure out exactly what is happening, so you're not hiding your implementation that carefully anyway.
I am simply reading information off the interwebs, currently the cmake about page, and I need the information to fill in the gaps, it helps to see the big picture.
Surely the answer is straightforward, I hope. What is a native build environment?
Context: I need to know how to build software on my machine (CodeBlocks, etc), why I need to do this, the advantages of doing this, etc. But first, I need to know every piece of jargon I come across, and I could not find any explanations about exactly what a "Native build environment" is, although I can speculate to some degree.
"Native" as in "runs directly in the host operating system" and not "runs in a virtual machine or emulator."
The particular point that CMake's about page is trying to convey is the manner in which CMake achieves cross-platform functionality: specifically not by virtualizing, but by cooperating/collaborating directly with the host system, and the "normal" ways the host system is used to doing things.
Is the build environment then just the directory holding all the garbage needed for a compiler to build the software then?
That's an oversimplification – there's nothing to say that it's a single directory – but more or less, yes. The term is not jargon, it literally means "the state of the world" (aka, environment) needed for the build.
What would you call the other thing then, Non-native?
Sure, or virtualized, or emulated, or whatever other intermediate layer has been added.
Why do we need the distinction as well?
Why not? It's useful to have a concise, clear, simple term so we can communicate precisely and with minimal confusion and ambiguity.
Why 'non-native'? If you haven't already figured this out - there is something called cross-compilation.
Simply put, if I don't have access to target hardware (or an equivalent virtual machine) on which the software needs to run, how do I develop this software on my host and package it to run on that target?
Cross-compilation addresses this by providing necessary tools that perform a translation (or other important low-level stuff) to give you the final software. Such an environment to develop software is called non-native.
Well, I believe we need the term to state the technique.
If I statically link an executable in ubuntu, is there any chance that that executable won't work within another distribution such as mint os? or fedora? I know processor types are affected, but other then that is there anything else I have to be wary of? Sorry if this is a dumb question. Thanks for any help
There are a few corner cases, but for the most part, you should be in good shape with static linking. The one that comes to mind is libnss. This particular library is essentially impossible to link statically, because of the way it does its job (permissions, authentication, security tasks). As long as the glibc-versions are similar, you should be ok on this issue, though.
If your program needs to work with subtle features of the kernel, like volume managers, you've got a pretty slim chance of getting your program to work, statically linked, across distros, because the kernel interfaces may change slightly.
Most typical applications, the kind that even makes sense to discuss portability, like network services, gui-applications, language tools (like compilers/interpreters) wont have a problem with any of this.
If you statically link a program on one computer and then move it to another computer in which the system basically runs the same way, then it should work just fine. That's the point of static linking; that there are no other files the program depends on - it's entirely self-contained, so as long as it can run at all, it will run the same way it does on its "host" system.
This contrasts with dynamic linking, in which the program incorporates elements of other files (libraries) at runtime. If you move a dynamically linked program to another system where the libraries it depends on are different (or nonexistent), it won't work.
In most cases, your executable will work just fine. As long as your executable doesn't depend on anything unusual being present for it to function, there will be no problem. (And, if it does depend on something unusual being present, then you'll have the same issue even if you dynamically link.)
Statically linking is usually safer than dynamically linking for compatibility between different UNIX environments, as long as the same CPU is in use.
To have a statically linked binary fail, again assuming the same processor architecture, you would have to do something such as link on a system using the a.out binary format and try to execute it on a system running ELF, in which case the dynamically linked version would fail just as badly.
So why do people not routinely link statically? Two reasons:
It makes the executable larger, sometimes MUCH larger, and
If bugs in the libraries are fixed, you'll have to relink your program to get access to the bug fixes. If a critical security bug is fixed in the libraries, you have to relink and redistribute your exe.
On the contrary. Whatever your chances are of getting a binary to work across distributions or even OSes, those chances are maximized by static linking. Static linking makes an executable self-contained in terms of libraries. It can still go wrong if it tries to read a file that's not there on another system.
For even better chances of portability, try linking against dietlibc or some other libc. An article at Linux Journal mentions some candidates. A smaller, simpler libc is less likely to depend on things in the filesystem that differ from distro to distro.
I would, for the reasons noted above avoid statically linking something unless you absolutely must.
That being said, it should work on any other similar kernel of the same architecture (i.e. if you statically link on a machine running linux 2.4.x , the loader VDSO is going to be different on linux 2.6, VDSO being virtual dynamic shared object, a shared object that the kernel exposes to every process containing loader code).
Other pitfalls include things in /etc not being where you'd think, logs being in different places, system utilities being absent or different (ubuntu uses update-rc.d, RHEL uses chkconfig), etc.
There are sometimes that you just have no choice. I was writing a program that talked to LVM2's string based cmdlib interface in favor of using execv().. low and behold, 30% of the distros I needed to support did NOT include that library and offered no way of getting it. So, I had to link against the static object when producing binary packages.
If you are using glibc, you can be confident that stuff like getpwnam() and friends will still work .. just make sure to watch any hard coded paths (better yet, make them configurable at run time)
As long as you can guarantee it'll only be executed on a similar version of the OS on similar hardware your program will work fine if it statically linked. so, if you build for a 2.6 Linux and statically link you will be fine to run on (almost) all 2.6 Linux distributions.
Be warned you can't statically link some parts of GLIBC so if you're using them you'll have to dynamically link anyway. From memory the name service stuff (nss) parts required dynamic linking when I was investigating it.
You can't statically link a program for (say) Linux then expect it to run on BSD or Windows. BSD and Unix don't present or handle their system calls in the same way Linux does. I tell a slight lie because the BSDs have a Linux emulation layer that can be enabled, but out of the box it won't work.
No it will not work. Static linking for distribution independence is a concept from the old unix ages and is not recommended. By the fact you can't as many libraries are not avail as static libraries anyway.
Follow the Linux Standard Base way, this is your only chance to get as much cross distribution portability as possible.
The LSB also works fine if you program for FreeBSD and Solaris.
There are two compatibility questions at issue here: library versions and library inventory.
You don't say what libraries you are using.
If you have no '-l' options, then the only 'library' is glibc itself, which serves as the interface to the kernel. Glibc versions are upward compatible. If you link on a glibc 2.x system you can run on a glibc 2.y, for y > x. The developers make a firm commitment to this.
If you have -l options, static linking is always safe. If you are dynamically linked, you have to ensure that (1) the library is present on the target system, and (2) has a compatible version. Your Mileage Might Vary as to whether the target distro has what you need.