Visopsys: one man's vision to build an operating system
Linked by Thom Holwerda on Mon 17th Sep 2012 16:56 UTC, submitted by Andy McLaughlin
OSNews, Generic OSes "Visopsys (VISual OPerating SYStem) is an alternative operating system for PC-compatible computers, developed almost exclusively by one person, Andy McLaughlin, since its inception in 1997. Andy is a 30-something programmer from Canada, who, via Boston and San Jose ended up in London, UK, where he spends much of his spare time developing Visopsys. We had the great fortune to catch up with Andy via email and ask him questions about Visopsys, why he started the project in the first place, and where is it going in the future."
E-mail Print r 2   46 Comment(s) http://osne.ws/kcr
Permalink for comment 535683
To read all comments associated with this story, please click here.
RE[3]: The hardest part
by Brendan on Wed 19th Sep 2012 11:55 UTC in reply to "RE[2]: The hardest part"
Brendan
Member since:
2005-11-16

1. "Some OSs (e.g. Linux) had religious objections ('OMG what if we wrote drivers and Microsoft could use them!')"

Well, presumably the manufacturers would be on board (if they weren't the model would be bound to fail anyways). This means the manufacturers would be providing the drivers and that they would run on linux, visopsys, hurd, etc. as well as windows.


Almost all hardware manufacturers only care about Windows; and like you already said, Microsoft has nothing to gain from adopting this. The rare few manufacturers that do care about anything else (NVidia, ATI/AMD, Intel) only care about Linux. Linux developers (and GNU specifically) are the people that refused to support UDI for religious reasons ( http://www.gnu.org/philosophy/udi.html ).

2. "some OSs had security problems ('OMG binary blobs created by unknown third-party developers running at the highest privilege level because our kernel is monolithic!')"

This is true. In principal I don't object to requiring source code with drivers, but that's not a very realistic sale. Many linux distros already have proprietary blobs, and nobody would be forced to install those. On the one hand, the high availability of shared manufacturer drivers could decrease the incentive of volunteers to write open source drivers for the same hardware. On the other hand, these volunteers could put their time to much better uses instead of reinventing the wheel.


Linux has some binary blobs; but they don't like it and would get rid of them if they could. It'd be extremely hard to convince them to replace existing/working open source drivers with alternative (potentially closed source) drivers.

Ultimately though if you don't trust the manufacturer of your hardware to write stable/trustworthly software, then arguably you've got no business installing their hardware on your machine either.


It's not the hardware manufacturers that would be writing drivers. It's people volunteering their time to slap together something that "works for me(tm)".

3. "and some OSs had technical reasons for not using it (e.g. very different driver interfaces, capabilities and feature sets)."

This is indeed probably one of the more controversial aspects, but the way I see it the drivers should be as modular as possible to make it easy to hook them into however the OS needs them.


In this case, people/volunteers will only write the modules for the OS they care about and the driver won't work on any OS that needs different modules.

At the extreme, all operating systems today have no choice but to work with fixed interfaces anyways (ones provided by the hardware). Moving this into software shouldn't be that much of a burden to a system's design.


A driver is a kind of abstraction layer between whatever interface the OS wants and whatever interface the hardware provides. What you're talking about is having drivers that provide an unwanted interface, with a "driver driver" between the unwanted interface and the OS itself.

Like I said earlier, *ideally* this wrapping layer would be in a kind of source form and it's overhead could be optimised away when it's compiled&linked with callees within the OS.


Trying to get different developers to agree on a common device driver standard will be hard. Trying to get different developers to agree on a common programming language is going be even harder.

"The ancient BIOS services are not acceptable because they're single-tasking synchronous interfaces (e.g. your OS freezes while the firmware waits until a DMA transfer completes)."

Great observation. Clearly these would have to be asynchronous. Also, all device drivers should be able to run in parallel on SMP. Which is a reasonable requirement assuming they don't share resources.


Not just asynchronous, but "asynchronous with IO priorities". For example, you should be able to say "pre-fetch these sectors as low priority" and also say "change the priority of my earlier request (I need them sectors ASAP!)" or "cancel that request, I don't need those sectors now".

Not just different drivers running at the same time, but the same driver being able to complete multiple requests at the same time (e.g. if there's some sort of sector cache or something) and accepting new requests while existing requests are being performed.

Of course this is just the tip of the iceberg (e.g. I was only really looking at some aspects of storage device drivers). If you want to look at something like video driver interfaces then the sheet really hits the fan.

I wish there would be a viable market for this, it is a project I think I would enjoy working on.


A lot of people wish it was viable. Some try to do it (UDI, EDI/Extensible Device Interface). It hasn't worked yet.

I'm not necessarily saying it's impossible though - just very unlikely to become widespread.

- Brendan

Reply Parent Score: 2