Linked by Thom Holwerda on Mon 17th Sep 2012 16:56 UTC, submitted by Andy McLaughlin
"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."
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RE[3]: The hardest part
by Laurence on Wed 19th Sep 2012 07:59
in reply to "RE[2]: The hardest part"
Member since:2007-03-26
I don't think so, but it's worth investigating. Linux can call VESA or UEFI without becoming more hybrid (note that's not the exact model I'm proposing per-say, but I never the less think it's a valid counter-example).
I'm not sure those examples are applicable as VESA is an agreed standard where each OS has incorporated their own drivers and UEFI happens outside of the OS.
ndiswapper might be an applicable comparison though as that runs Windows drivers on a Linux kernel. I don't pretend to be an expert on how ndiswapper works, but from what I gather, it's quite similar to FUSE; ie it has a kernel driver but the actual imported drivers (be that ntfs-3g in FUSE or a Windows wireless driver in ndiswapper) will run in user space.
I'm not sure if the same would be required if going down a totally universal driver set. Probably not. I'm not a kernel developer so not really in a position to comment hehehe
Actually my gut instinct is to say the opposite may be more of a concern, how would a microkernel incorporate these drivers?
I don't really follow your line of thinking there. I'm not saying you're wrong (I really don't want to come across like I'm knowledgeable here because I'm really not!) but I'd appreciate it if you could elaborate a little more please
Obviously the microkernel's goal is to isolate the drivers from one another, would it be able to jail the drivers and still have them work? That depends how they're written. The standard would have to be very clear about how drivers could interact with the system, no direct manipulation of GDT or interrupt tables, drivers would need to request permission to access ports instead of assuming they're running in ring-0. They'd need standard ways to coordinate memory mapping. These murky details all need to be ironed out for sure, but with a well defined standard, a good reference implementation, a robust test suite, and a certification process, then we should have quality drivers that work everywhere without worrying about OS-specific quirks. I don't think an existing operating systems would need too many changes (assuming it's drivers were already modular and self-contained). It wouldn't be too different from writing a new OS-specific driver for a new piece of hardware, only this particular OS-specific driver will be capable of driving all hardware supported by the shared driver standard.
I might be saying something really stupid here, so please forgive me; but if the existing architecture has drivers written in a modular / self-contained way, then wouldn't that be a hybrid kernel?
I think I have a basic grasp on all this (I did experiment with writing my own kernel many years ago), but I'm definitely no more experienced than a curious n00b. So I apologise if I'm making no sense there.
Member since:2011-01-28
Laurence,
"I might be saying something really stupid here, so please forgive me; but if the existing architecture has drivers written in a modular / self-contained way, then wouldn't that be a hybrid kernel?"
Oh I see what you are thinking. Instead of explaining it in my own words, I'll drop a fairly decent wikipedia article on the matter:
https://en.wikipedia.org/wiki/Monolithic_kernel
"A monolithic kernel is an operating system architecture where the entire operating system is working in the kernel space and alone as supervisor mode."
and
"Modular operating systems such as OS-9 and most modern monolithic operating systems such as OpenVMS, Linux, BSD, and UNIX variants such as SunOS, and AIX, in addition to MULTICS, can dynamically load (and unload) executable modules at runtime. This modularity of the operating system is at the binary (image) level and not at the architecture level. Modular monolithic operating systems are not to be confused with the architectural level of modularity inherent in Server-Client operating systems (and its derivatives sometimes marketed as hybrid kernel) which use microkernels and servers (not to be mistaken for modules or daemons)."
In short, a hybrid or microkernel differs in that it uses the CPU segregation mechanisms to protect pieces of the kernel from itself. This typically has further implications, like microkernel modules needing to communicate via IPC instead of being able to hook into each other more directly via dynamic linking or function pointers. But either kernel style could have pluggable modules (similar to DLLs).
Features
Linked by Thom Holwerda on 06/13/13 14:35 UTC
The third and final WWDC product I want to talk about is - of course - OS X 10.9 Mavericks. While iOS 7 was clearly the focus of this year's WWDC, its venerable desktop counterpart certainly wasn't left behind. Apple announced OS X 10.9 Mavericks, the first OS X release not to carry the name of a big cat.
Linked by Thom Holwerda on 06/11/13 17:07 UTC
We already talked about iOS 7 yesterday (after a night of sleep, it's only looking worse and worse - look at this, for Fiona's sake!), so now it's time to talk about the downright stunning and belly flutters-inducing new Mac Pro. As former owner and huge, huge, huge fan of the PowerMac G4 Cube - I haven't been this excited about an Apple product since, well, I would say the iMac G4. This is the Apple I used to love.
Linked by Thom Holwerda on 06/10/13 23:13 UTC
Apple held its big keynote event thing at WWDC earlier this evening, but since I was away with friends I've had to read up on it later in the evening. The company announced iOS 7, OS X 10.9 Mavericks, and they gave a preview of the new Mac Pro. Especially the Mac Pro impressed me, and while iOS 7's new Holo/Metro-inspired theme looks messy and garish to me, I do commend Apple for finally breaking the mold. This news item will focus on iOS 7 - I'll dive into the Mac Pro and OS X 10.9 tomorrow (it's late here now).
Linked by Thom Holwerda on 06/08/13 14:57 UTC
And yes, the PRISM scandal is far, far from over. More and more information keeps leaking out, and the more gets out, the worse it gets. The companies involved have sent out official statements - often by mouth of their CEOs - and what's interesting is that not only are these official statements eerily similar to each other, using the same terms clearly designed by lawyers, they also directly contradict new reports from The New York Times. So, who is lying?
Linked by Thom Holwerda on 06/07/13 11:40 UTC
This story is getting bigger and bigger. Even though most Americans probably already knew, it is now official: the United States government, through its National Security Agency, is collecting the communications and data of all American citizens, and of non-Americans using American services, through a wide collaboration with the large companies in technology, like Apple, Google, Microsoft, Facebook, and so on. Interestingly enough, the NSA itself, as well as the US government, have repeatedly and firmly denied this massive spying on Americans and non-Americans took place at all.
Linked by Thom Holwerda on 06/04/13 12:45 UTC
Ah, patents - the never-ending scourge of the technology industry. Whether wielded by companies who don't actually make any products, or large corporations who abuse them because they can't compete in the market place or because they're simply jerks, they do the industry a huge disservice and are simply plain dangerous. According to The Wall Street Journal (circumvention link), president Obama is about to take several executive actions to address patent trolls - which may seem like a good idea, but I am very worried that all this will do is strengthen the positions of notorious patent system abusers such as Apple and Microsoft.
Linked by nfeske on 05/31/13 10:12 UTC
With version 13.05, the developers of the Genode OS Framework take measures to ensure that Genode continues to scale well with a growing number of users and the steadily broadening platform coverage. Further highlights are the improved SoC support for Exynos 5, OMAP4, Raspberry Pi, i.MX, and new components for realizing headless systems.
Linked by Thom Holwerda on 05/29/13 16:59 UTC
At the D11 conference, Apple CEO Tim Cook once again took the stage to be interviewed by Walt Mossberg and Kara Swisher. While most of the interview can be replicated by picking and reading 10 random Apple fanblog stories - there were still a number of very interesting things that warrant some closer scrutiny.
Linked by Thom Holwerda on 05/24/13 17:26 UTC
So, the Xbox One disaster continues. Microsoft's policy for dealing with the used games market has reportedly leaked - and it's a clear and direct attack to destroy the used games market. Prices for used games will be set at the retail value of a new game, and retailers have to hook into Microsoft's computer systems and comply with Microsoft's terms and conditions.
Linked by Thom Holwerda on 05/21/13 21:38 UTC
At an event earlier today, Microsoft unveiled the next Xbox - the third model, but confusingly named Xbox One. The big focus was TV, integrated Kinect, and all the other stuff we all expected to be forced down our throats. I think it took them 25 minutes to actually come to what should be the core of the story: gaming. Nothing groundbreaking in the gaming department, except for how Microsoft intends to handle the used games market and borrowing games from friends: pay up, buddy!More Features »
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Member since:
2011-01-28
Laurence,
"That's a great idea in theory, but wouldn't it push kernels into a more hybrid or even -dare I say it- micro kernel design?"
I don't think so, but it's worth investigating. Linux can call VESA or UEFI without becoming more hybrid (note that's not the exact model I'm proposing per-say, but I never the less think it's a valid counter-example). Actually my gut instinct is to say the opposite may be more of a concern, how would a microkernel incorporate these drivers?
Obviously the microkernel's goal is to isolate the drivers from one another, would it be able to jail the drivers and still have them work? That depends how they're written. The standard would have to be very clear about how drivers could interact with the system, no direct manipulation of GDT or interrupt tables, drivers would need to request permission to access ports instead of assuming they're running in ring-0. They'd need standard ways to coordinate memory mapping. These murky details all need to be ironed out for sure, but with a well defined standard, a good reference implementation, a robust test suite, and a certification process, then we should have quality drivers that work everywhere without worrying about OS-specific quirks. I don't think an existing operating systems would need too many changes (assuming it's drivers were already modular and self-contained). It wouldn't be too different from writing a new OS-specific driver for a new piece of hardware, only this particular OS-specific driver will be capable of driving all hardware supported by the shared driver standard.
Edited 2012-09-18 16:07 UTC