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QNX is now free for anything non-commercial, plus there's an RPi image

blackberry.qnx.com

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Re: QNX is now free for anything non-commercial, plus there's an RPi image

#361

Post by [deleted] »

pjmlp wrote: post #289
Y_Y wrote: post #278

Earlier quoted context omitted.

> LLVM and clang specifically started eating its lunch I don't know how you can eat GCC's lunch. I feel like in this analogy GCC eats from a communal trough and is very happy to share. A company that sells licenses can lose customers, the GNU project just wants the world to benefit. GCC is still ubiquitous and has plenty of developers and mindshare, what more could they want?

Basically most of the embedded folks that used GCC forks are now on clang, and if in the old days they were breaching GPL, nowadays they are fully compilant, so not upstreaming is not even a legal issue any longer.

[deleted]

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#362

Post by vacuity »

andreww591 wrote: post #248
mwcampbell wrote: post #130

Earlier quoted context omitted.

> Somebody really should write a microkernel like this in Rust. I wonder how far Redox's microkernel design is from what that comment describes.

Redox's IPC is a fair bit weaker of a design than that of QNX or my seL4-derived kernel. It works sort of like that of QNX in that it has direct copying of messages between address spaces and RPC-like semantics with direct context switch from sender to receiver and back, but it is more limited and implemented in a slower way. Also, there seems to be no consideration for real-time performance at all. Outside the core…

I think elaborate IPC designs are too much trouble, and I favor seL4's "context switch with benefits" approach of delegating larger messages to shared memory. It avoids performance and security hiccups with copying or kernel-mediated shared memory, like in EROS. To be fair, I'm less focused on efficiency and more on simplicity/robustness of the kernel, similar to seL4. Could you elaborate on your thoughts in the IPC space?

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#363

Post by Matumio »

CoastalCoder wrote: post #310
jonaias wrote: post #224

Earlier quoted context omitted.

RT Linux is not the only alternative. There are now plenty of options for achieving hard real-time performance without relying on proprietary RTOS solutions: Dedicated Real-Time Cores: Many SoCs include dedicated cores specifically for hard real-time tasks. Microcontroller Companions: Pairing a microcontroller running a lightweight RTOS with a larger, general-purpose processor as a supervisor (You can use normal Linu…

Out of curiosity, to what extent can modern x86 / Arm systems support hard-realtime guarantees? I'm wondering about things that could cause unexpected delays, like PCIe bus contention / error correction, high interrupt traffic, etc. (I don't know much about this topic, so apologies if my question is ill-conceived.)

If by "modern" you mean a desktop/server CPU, the problem is the complexity that exists because of optimization for average throughput. Do you really know how long you will wait, worst-case, if three different cores flush the same cache line back to DRAM? Or maybe some niche hardware you use has some funky behaviour that stalls some hardware bus, or waits in the kernel for a millisecond, twice a month or whatever.

On the other hand, on FPGAs, deterministic timing is so very simple. Your output will not be a single clock cycle late even if something else goes wrong in logic running on the same FPGA (except through a connection that you control).

If you really want to know, OSADL has a QA Farm that monitors worst-case interrupt and scheduling latency for various CPUs and Linux versions.

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#364

Post by vacuity »

vbezhenar wrote: post #293
caskstrength wrote: post #266

Earlier quoted context omitted.

> For everything else, including desktop and mobile operating systems realtime sounds like a good idea. Why on earth would you need real time on desktop? Every time the topic is discussed on internet bunch of confused people chime in with this sentiment that doesn't make much sense. "RTOS" is not some magic that somehow makes everything on your desktop fast. All it would do in reality is make everything slower for 99…

I've read many opinions of those who used QNX on desktop in the past, that it felt much more "snappy" compared to other systems. Desktop definitely has real time tasks. Any animation is real time task. When I'm listening to music, it's real time task. macOS sound interrupts for a short time, when something hardware-related happens, so it's not pleasant experience. You might argue that user can tolerate those interrup…

Indeed. There are people who have a fair point that desktops for users (as opposed to servers) should have a focus on being responsive and useful. Like how writing on a piece of paper produces meaningful markings in real time, user interfaces should be able to perform tasks with analogous interactivity. See comments about BeOS elsewhere in this thread. I don't know about the extreme, but the overall sentiment is valuable and a far cry from the current state of the desktop experience.

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#366

Post by rbanffy »

stackghost wrote: post #351
rbanffy wrote: post #283

Earlier quoted context omitted.

I still want one. Can’t find any.

I still have mine but it's useless because it isn't receiving updates and can't run third party OSes due to the locked down boot chain.

Still runs the base BB 10 apps. My Q-10 still works as a phone. And can read e-mail.

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#367

Post by 486sx33 »

Animats wrote: post #45

If only you could believe them. QNX has been "opened" twice before. Each time, there was a rug pull, and it went closed again. Before the first rug pull, open source groups routinely added QNX to their target list. There was a Firefox for QNX. Eclipse had QNX as a target. GCC and most of the Gnu command line tools could be built for QNX. There was a desktop environment, Photon. I used that as a primary desktop for th…

Unreal engine has certainly had its licensing issues.

https://www.theverge.com/2023/10/5/23905082/epic-unreal-engi...

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#368

Post by bregma »

eitland wrote: post #299
bregma wrote: post #285

Earlier quoted context omitted.

There are not any real time patches for Linux: there's only the low-latency kernel. Low-latency and realtime are different things. A lot of the time the two can appear superficially similar, until they don't and your airplane falls out of they sky. The realtime executives are not operating systems. Executives and operating systems are two different things. QNX is a realtime operating system. It addresses the niche of…

A major upgraded was landed recently: https://www.infoq.com/news/2024/10/linux-6-12-real-time/

A preemptable kernel does not make Linux a realtime OS. A low-latency kernel does not make Linux a realtime OS. There are great things in their niches but when you need a realtime OS, Linux is still not going to be fit for purpose.

Re: QNX is now free for anything non-commercial, plus there's an RPi image

#369

Post by lproven »

stackghost wrote: post #196
rbanffy wrote: post #154

Earlier quoted context omitted.

> Bb10 was its own little adventure but had similar draconian dx I did some development for it but the bureaucracy killed my will to do more. It was a great phone OS though. The real time nature makes even modest hardware responsive.

The BB10-powered Passport was my favorite device

> The BB10-powered Passport was my favorite device

I loved mine.

My favourite device was my Nokia E90 Communicator. Hardware-formfactor-wise that's the best smartphone I ever owned.

Closed, it's a one-hand T9-driven smart candybar phone. Open, it has a usable QWERTY keyboard, a letterbox screen that can display a slice of an A4 or Legal PDF at readable size. I never watched films on it, but you could do in principle.

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