s/image/email/ How I miss an edit feature on emails :-D
On Thu, Nov 20, 2025 at 5:17 PM Alan C. Assis <[email protected]> wrote: > BTW, I'm saying that the idea of creating the VOTE image was yours, just > saying you commented we need to have a vote for that PR that disables > signals. ;-) > > BR, > > Alan > > On Thu, Nov 20, 2025 at 5:13 PM Alan C. Assis <[email protected]> wrote: > >> Mateusz, >> >> Since the idea of voting came from you in the first place, could you >> please start a separate thread to DISCUSS it? :-) >> >> BR, >> >> Alan >> >> On Thu, Nov 20, 2025 at 5:03 PM raiden00pl <[email protected]> wrote: >> >>> It's become quite a mess here, starting with the thread titled VOTE >>> without DISCUSSION :) The title also suggests that the lack of >>> POSIX compliance in NuttX is something new, which is not true. >>> >>> We've touched two separate topics here that I think deserve >>> their own separate discussion. The first topic: should we introduce >>> an option to disable signal support, similar to how we currently >>> disable pthreads or POSIX timers? Both options are not >>> POSIX-compliant, but are useful for small systems and they >>> have been in NuttX for a long time. >>> >>> The second topic is support for POSIX subprofiles (like PSE51), >>> but this is the topic for later. >>> >>> czw., 20 lis 2025 o 20:53 Tomek CEDRO <[email protected]> napisał(a): >>> >>> > Alan, Raiden, what is the exact proposition here being voted? >>> > One sentence that can be answered yes or no. >>> > >>> > It looks like a proposition to make NuttX "NOT POSIX Compliant". >>> > This violates fundamental architecutral concept and inviolables of >>> NuttX. >>> > Thus my answer is NO. >>> > >>> > Implication of answering yes here is enabling mess in the long term. >>> > Because vote is not well defined, undocumented, with no examples or >>> > prototypes, anything that is on purpose not POSIX compliant could >>> > legally become part of NuttX making if purposefully non-posix >>> > compliant which violates its founding principle, and all this could be >>> > attributed to this vote. >>> > >>> > As a BSD Unix user on my desktop I understand that pretty well, NuttX >>> > has BSD Unix roots too and I love it! >>> > I will not tell anything about other OR/RTOS except they may not care >>> > about self-compatibility and standards a lot, and people have choice >>> > what to use or what to avoid. >>> > >>> > If anyone wants to trim down their firmware image removing all sorts >>> > of unused parts, that is their choice, I am fine with that, I also >>> > need that. >>> > >>> > But to introduce "NOT POSIX Compliant" to a project where "POSIX >>> > Compliance" is a design principle looks self-contradictory. >>> > >>> > Lets have a discussion first, know the details, align the solution, >>> then >>> > vote. >>> > Lets not vote by surprise because voting is binding. >>> > >>> > Hugs :-) >>> > Tomek >>> > >>> > -- >>> > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info >>> > >>> > On Thu, Nov 20, 2025 at 8:23 PM Alan C. Assis <[email protected]> >>> wrote: >>> > > >>> > > Exactly!!! >>> > > >>> > > If we remove all non-POSIX features and remove all chips that doesn't >>> > have >>> > > MMU, NuttX will run only in 3 or 4 boards. >>> > > >>> > > Is this the direction we want to go? >>> > > >>> > > BR, >>> > > >>> > > Alan >>> > > >>> > > On Thursday, November 20, 2025, raiden00pl <[email protected]> >>> wrote: >>> > > >>> > > > TBH, I don't understand these -1 votes... >>> > > > >>> > > > NuttX isn't fully POSIX-compliant and never will be, unless we >>> > > > want to get rid of 80% of the supported targets. Full POSIX >>> compliance >>> > > > requires an MMU, for example, for proper mmap() implementation. >>> > > > You can't support "deeply-embedded environments" (quote from doc) >>> and >>> > > > full POSIX at the same time. This is an obvious contradiction. >>> > > > POSIX profiles (PSE) improve this somewhat, but an MMU is still >>> > required >>> > > > for full compatibility (mmap issue). >>> > > > >>> > > > So what about the features currently present in NuttX that are >>> > obviously >>> > > > not POSIX-compliant? Like everything in `menuconfig >>> DISABLE_OS_API`. >>> > > > Even the NuttX documentation indirectly states from the very >>> beginning >>> > that >>> > > > NuttX is NOT fully POSIX because it doesn't support fork() which is >>> > > > required >>> > > > by the POSIX base specification. >>> > > > >>> > > > czw., 20 lis 2025 o 19:41 Tomek CEDRO <[email protected]> >>> napisał(a): >>> > > > >>> > > > > -1 from me as per this vote too sorry. >>> > > > > >>> > > > > I am sure there are other ways to accomplish that goal. >>> > > > > >>> > > > > We do not want to communicate officially in any way that we are >>> "NOT >>> > > > > POSIX Compliant" on purpose when we clearly state in many places >>> > > > > "strict POSIX and ANSI compliance" including the Inviolables. >>> That >>> > > > > will make us incoherent and self-contradictory. >>> > > > > >>> > > > > As in my previous response, trimming down the firmware in extreme >>> > > > > cases can be achieved by removing unused functionalities, at the >>> > > > > individual responsibility of the developer. I know there may be >>> use >>> > > > > cases for that, and people still want to use NuttX not the other >>> > RTOS, >>> > > > > which is important. >>> > > > > >>> > > > > My proposition is to clearly mark all POSIX functionalities, >>> that are >>> > > > > enabled and available by default, and when any of them is removed >>> > then >>> > > > > final solution is not POSIX compliant (may be not even used this >>> is >>> > up >>> > > > > to the firmware developer) but necessary to accomplish the task. >>> This >>> > > > > provides a choice for trimming down the firmware image but >>> sticks to >>> > > > > POSIX/ANSI by default. >>> > > > > >>> > > > > This way we stick to POSIX/ANSI compliance by default. We have >>> clear >>> > > > > identification of POSIX / PE51 parts. We allow trimming down the >>> > final >>> > > > > firmware in known range of POSIX / PE51 or beyond. >>> > > > > >>> > > > > What do you think? :-) >>> > > > > >>> > > > > -- >>> > > > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info >>> > > > > >>> > > > > On Thu, Nov 20, 2025 at 7:16 PM Gregory Nutt < >>> [email protected]> >>> > > > wrote: >>> > > > > > >>> > > > > > -1 >>> > > > > > >>> > > > > > Bad idea. Destroys the core value proposition for the OS. >>> > > > > > ________________________________ >>> > > > > > From: Alan C. Assis <[email protected]> >>> > > > > > Sent: Thursday, November 20, 2025 5:05 AM >>> > > > > > To: [email protected] <[email protected]> >>> > > > > > Subject: Re: [VOTE] Add support to NOT POSIX Compliant (or >>> should >>> > be >>> > > > add >>> > > > > support ?) >>> > > > > > >>> > > > > > Hi Greg, >>> > > > > > >>> > > > > > Yes, I think the idea is to support POSIX subprofiles, this is >>> the >>> > case >>> > > > > for >>> > > > > > pthread, posix timers, signals, etc. >>> > > > > > >>> > > > > > I think these extreme cases are low end MCUs where we can >>> offer the >>> > > > > option >>> > > > > > to run a small version of NuttX, without jeopardizing the >>> usage for >>> > > > > people >>> > > > > > who need a compliant POSIX OS. >>> > > > > > >>> > > > > > BR, >>> > > > > > >>> > > > > > Alan >>> > > > > > >>> > > > > > On Thu, Nov 20, 2025 at 9:50 AM Gregory Nutt < >>> [email protected]> >>> > > > > wrote: >>> > > > > > >>> > > > > > > There should only be extreme conditions where any POSIX API >>> is >>> > > > > > > non-compliant. POSIX complience is a core value of the OS >>> and >>> > should >>> > > > > not >>> > > > > > > be violated. If we lose POSIX compliance then we have >>> > destroyed the >>> > > > > > > meaning for the existence of the operating system. I hopr >>> that >>> > no >>> > > > one >>> > > > > will >>> > > > > > > ever tolerate that to happen. >>> > > > > > > >>> > > > > > > The only legitimate cases I can think of are due to hardware >>> > > > > limitations. >>> > > > > > > For example, certain features of mmap() and fork() cannot be >>> > support >>> > > > if >>> > > > > > > there is no MMU. uCLinux had the same limitations. >>> > > > > > > ________________________________ >>> > > > > > > From: Alan C. Assis <[email protected]> >>> > > > > > > Sent: Thursday, November 20, 2025 4:39 AM >>> > > > > > > To: dev <[email protected]> >>> > > > > > > Subject: [VOTE] Add support to NOT POSIX Compliant (or >>> should be >>> > add >>> > > > > > > support ?) >>> > > > > > > >>> > > > > > > Hi Everyone, >>> > > > > > > >>> > > > > > > Some years ago NuttX was able to fit in really small MCUs (in >>> > fact I >>> > > > > got it >>> > > > > > > running on a chip using less than 2KB RAM). >>> > > > > > > >>> > > > > > > But a few years ago those options to disable SIGNALS, VFS, >>> etc >>> > were >>> > > > > > > disabled to create a system that was fully POSIX compliant. >>> > > > > > > >>> > > > > > > Unfortunately we missed the details: POSIX also aims at >>> systems >>> > > > without >>> > > > > > > resources, as is the case of POSIX PE51 (POSIX PSE51 is a >>> > specific, >>> > > > > minimal >>> > > > > > > profile or subset of the full POSIX - Portable Operating >>> System >>> > > > > Interface >>> > > > > > > standard, formally defined in IEEE 1003.13-2003). >>> > > > > > > >>> > > > > > > Almost two years ago I opened an issue about it: >>> > > > > > > https://github.com/apache/nuttx/issues/11390 >>> > > > > > > >>> > > > > > > Today Mr Chengdong opened a PR to bring back the possibility >>> to >>> > > > disable >>> > > > > > > signals: >>> > > > > > > https://github.com/apache/nuttx/pull/17352 >>> > > > > > > >>> > > > > > > But as Mateusz (raiden00pl) pointed we need to be careful >>> about >>> > it to >>> > > > > avoid >>> > > > > > > breaking the Inviolables: >>> > > > > > > >>> > > > > > > ## Strict POSIX compliance >>> > > > > > > >>> > > > > > > - Strict conformance to the portable standard OS interface >>> as >>> > > > > defined at >>> > > > > > > OpenGroup.org. >>> > > > > > > >>> > > > > > > >>> > > > > > > * - A deeply embedded system requires some special support. >>> > Special >>> > > > > > > support must be minimized.* - The portable interface must >>> never >>> > be >>> > > > > > > compromised only for the sake of >>> > > > > > > expediency. >>> > > > > > > - Expediency or even improved performance are not >>> > justifications >>> > > > for >>> > > > > > > violation of the strict POSIX interface. >>> > > > > > > >>> > > > > > > Fortunately Greg chose well his words: "Special support must >>> be >>> > > > > minimized". >>> > > > > > > It doesn't mean it could exist, we just need to take care to >>> not >>> > > > become >>> > > > > > > normal or goal and jeopardize the system. >>> > > > > > > >>> > > > > > > So in this sense I propose to vote a suggestion: >>> > > > > > > >>> > > > > > > In the configuration where we already add an option to >>> disable >>> > posix >>> > > > > timer, >>> > > > > > > pthreads, etc we add an option to "Enable POSIX PE51 subset". >>> > > > > > > >>> > > > > > > This way someone willing to disable signals will be aware >>> he/she >>> > is >>> > > > > > > creating a system that is not POSIX fully compliant or it is >>> > just a >>> > > > > subset >>> > > > > > > of a POSIX OS. >>> > > > > > > >>> > > > > > > BR, >>> > > > > > > >>> > > > > > > Alan >>> > > > > > > >>> > > > > >>> > > > >>> > >>> >>
