Amiga's kernel

[obscurepanic]

In Wikipedia, AmigaOS has an atypical microkernel.

http://en.wikipedia.org/wiki/Amigaos

As I googled it deeper, I bumped into an website and saw a comment:

AmigaOS is a beast on its own. Yes it was designed like a microkernel, with each device and filesystem having their own thread (task), but it doesn't actually have any enforced boundary between userland and kernel land, nor memory protection, which greatly lowers the latency. It's like a single kernel process running each app as a different thread in the kernel.

http://www.haiku-os.org/community/forum/haiku_kernel_architecture_questions_0

How does the kernel really work in Amiga vis-a-vis its architecture?

[bloodline]

In Wikipedia, AmigaOS has an atypical microkernel.

http://en.wikipedia.org/wiki/Amigaos

As I googled it deeper, I bumped into an website and saw a comment:



http://www.haiku-os.org/community/forum/haiku_kernel_architecture_questions_0

How does the kernel really work in Amiga vis-a-vis its architecture?

The quote you have from Wiki/google, just about sums it up. What is your question exactly?

[obscurepanic]

The quote you have from Wiki/google, just about sums it up.

You mean an application on AmigaOS act like a minicomputer on its own?

What is your question exactly?

How AmigaOS' architecture and kernel really works. I'm not too familiar with Amiga, so I was curious. Even the previous example quote was a wee bit to understand.

Why being atypical? No huge difference between the kernel and userland? What points are very different from a generic UNIX monolithic kernel?

Thank you.

[the_leander]

Whilst no expert on the subject, you wouldn't go far wrong in looking into things like AmigaOS's lack of memory protection to begin with.

As for kernel comparasons, you might be better off comparing Exec to L4 or QNX or Minix or even Hurd.

[krashan]

How AmigaOS' architecture and kernel really works. I'm not too familiar with Amiga, so I was curious. Even the previous example quote was a wee bit to understand.

The thing is rather simple. From unix point of view the whole AmigaOS including all running applications, is a single process. Every application and all asynchronous system services are threads of this process. Then all these share a single address space. That is why there is no separation between so called "kernel" and "userland".

Advantages of this approach are speed and low demand for system resources (CPU time, memory). The main disadvantage is that one badly coded (or intentionally malicious) application can drag down the whole system.

Another difference is very high modularity. The "real" kernel is very small, below 50 kB for 68k machines. Then all higher layer system services including all device drivers, filesystems etc. are external modules. For classic Amigas a few most important service modules have been placed in ROM memory (so called Kickstart), modern ones (+ clones) load all from disk. These modules, called libraries use specific form of runtime linking, different than *.so or *.dll, they use jumptables to defined API vectors, so no symol resolving happens at module load.

[AJCopland]

An interesting statement on that WikiPedia entry : "The current holder of the Amiga intellectual properties is Intel."
It's not referenced so no idea of its validity, typical wikipedia entry really.

[bloodline]

You mean an application on AmigaOS act like a minicomputer on its own?



How AmigaOS' architecture and kernel really works. I'm not too familiar with Amiga, so I was curious. Even the previous example quote was a wee bit to understand.

Why being atypical? No huge difference between the kernel and userland? What points are very different from a generic UNIX monolithic kernel?

Thank you.

AmigaOS is like a microkernel, in as much as everything is modular, sitting on top of a simple memory/process/interrupt management core... but Amiga OS doesn't suffer the performance penalty of other microkernels because it has no security at all.

A microkernel protects the core from all the other parts of the system, so you can in theory replace/upgrade/restart/break any part of the system without taking down the rest of the system, this is the power of a microkernel...
AmigaOS doesn't and thus is atypical (by missing out on this one key advantage of a microkernel, the trade off being that AmigaOS is faster and more memory efficient than regular microkernel) .

[DiskDoctor]

AmigaOS is like a microkernel, in as much as everything is modular, sitting on top of a simple memory/process/interrupt management core... but Amiga OS doesn't suffer the performance penalty of other microkernels because it has no security at all.

A microkernel protects the core from all the other parts of the system, so you can in theory replace/upgrade/restart/break any part of the system without taking down the rest of the system, this is the power of a microkernel...
AmigaOS doesn't and thus is atypical (by missing out on this one key advantage of a microkernel, the trade off being that AmigaOS is faster and more memory efficient than regular microkernel) .

As a matter of fact I see no harm in denying this feature.  Actually I don't think the harm in question is even comparable in scope to that one while using MSIE on an unprotected and badly secured/managed Windows desktop (which is roughly 80% world's personal computers' installation scheme).  Besides making any application registration layer (I mean certificates) solves the problem thoroughly.  All bad things we can see now is just an outcome of tremendous efforts of porting/writting apps for this very system.

I saw both Amiga and Morphos on local fairs yet in February and I was astonished by their performance.  Second time in my life.  First time was when I saw A500 back in those days.  Amiga nowadays is the only part of computer world which doesn't follow the Moore's law.  You can buy underpowered Sam and do whatever AOS is designed for and do it efficiently.  No matter the time or system (or processor if we're talking mobile), you always have to wait for everything.  Such a scalable system as AOS has a bright future I think, but maybe in 5-10 years.  Simple justification - computer OSes (mainly proprietary) appear in practically all digital equipment, get a 15$ mp3player and you'll see the market I mean.  Such systems like WinMobile, Symbian, even Android, WebOS are to fat for them already.  There goes the Amiga - that's how I see it and why I adore it.  But of course I prefer Amiga as a desktop :lol:

[stefcep2]

No matter the time or system (or processor if we're talking mobile), you always have to wait for everything.

I agree.  Modern computing is one step forward, 2 steps back: your hardware specs get higher and higher but it takes more and more time to do the simple things

[bloodline]

Originally Posted by DiskDoctor  
No matter the time or system (or processor if we're talking mobile), you always have to wait for everything.

I agree.  Modern computing is one step forward, 2 steps back: your hardware specs get higher and higher but it takes more and more time to do the simple things

Rubbish, Modern computing is getting better exponentially!

[the_leander]

Rubbish, Modern computing is getting better exponentially!

Shhh, don't tell them that, I mean afterall, running high end OS's on hardware way below the minimum spec is totally a valid comparason. :lol:

Yes stefcep2, that was aimed squarely at you.

Now, if you don't mind I'm going to go back to transcoding and editing some HD video.

[stefcep2]

Shhh, don't tell them that, I mean afterall, running high end OS's on hardware way below the minimum spec is totally a valid comparason. :lol:

Yes stefcep2, that was aimed squarely at you.

Now, if you don't mind I'm going to go back to transcoding and editing some HD video.

I'll just have to upgrade my c2d 2.6 ghz with 4 gig ram and 512mb nvidia card, I suppose..

[DiskDoctor]

Rubbish, Modern computing is getting better exponentially!

True but as long as you're getting most recent HW spec on each major release.

Besides I saw nothing for years, except for OSX release that is surpassed by Windows until now.

Nothing new.

WinXP for example was a polished version of W2K, with much less dll-driven exceptions.  W2K was the eventually stable (beta) version of Win95, WinNT actually.  Nothing happened until Vista, actually Vista was scr*wing up drivers policy and ripping off OSX UI.  I just got myself WIn7 which I find impossible to distinguish from Vista, jsut like 98 and ME. So from my perspective, more progress happened in Amiga world than in Windows world in the time of 1995-2009.

You say better graphics, cheaper RAM, faster and multi-core processors.  So what?  What for?  To make a new system supported?  Bollocks!  This is not a progress anymore - it is a scale effect lobbed by vendors to stabilize their income from selling HW.

Linux on Kubuntu example - nothing changed between 8 and 9 release, just most stuff is broken now since it's "just" released version.  What change might one expect from Linux anyway?  New gcc?  More Windows resemblance?  More ports, rip offs?  Drivers?  DivX codecs?

Macs allright, many new things have been appearing since 10.0 OS.

But those Windows issues for example - this is FMCG-like actions just to preserve clients from running into Macs, efficient actions though.

OK bloodline if you mean Macs fine, I agree it makes the whole thing undoubdetly better.  But keep in mind it would be 5% population and zero % office population.  These people ought to see hardly any change for last several years, if non-mac users report any progress it means they are properly targeted by MS marketing or misled by Linux mimics.

One more thing - I'm talking Desktop area only, servers - different story.  But Amiga is a desktop system, right?  And mobile for a change, as an ex-Palm owner all I can see now in smart mobiles is reverse-engineering the Palm world apps dated approximately on 2001/02 with everything slowed down by 5 x with 10 x better processor, more RAM, more etc.  So this is going down, not up.

This whole thing is embarrasing.  If like Databases you're talking - fine, the progress is huge.  But excluding servers and desktop macs there is NO actual (by a measure of computer science) progress here.

Sorry I must be blind or completely miseducated etc.  Or at least tasteless, aren't I?

[the_leander]

I'll just have to upgrade my c2d 2.6 ghz with 4 gig ram and 512mb nvidia card, I suppose..

Was it not you who was complaining of menu jerkiness with a Radeon 9200?

/cba to check the thread in question

[the_leander]

words

Uhuh...

You say better graphics, cheaper RAM, faster and multi-core processors.  So what?  What for?  To make a new system supported?  Bollocks!  This is not a progress anymore - it is a scale effect lobbed by vendors to stabilize their income from selling HW.

Yup, I could totally do what I do with video on an Amiga era hardware within a human lifetime and at the same quality.... (this is but one example)

Linux on Kubuntu example - nothing changed between 8 and 9 release, just most stuff is broken now since it's "just" released version.  What change might one expect from Linux anyway?  New gcc?  More Windows resemblance?  More ports, rip offs?  Drivers?  DivX codecs?

No progress you say...

OK bloodline if you mean Macs fine, I agree it makes the whole thing undoubdetly better.  But keep in mind it would be 5% population and zero % office population.  These people ought to see hardly any change for last several years, if non-mac users report any progress it means they are properly targeted by MS marketing or misled by Linux mimics.

The majority of tasks within an office have not changed - word processing, database entry etc. What has changed is how an office communicates both within a network and to the wider world. These capabilities require more powerful hardware.  

Consider the swathe of capabilities now open to a user of even a bottom end desktop PC. They can do things that 20 years ago would have been strictly the pervue of big studios, both in terms of video editing and special effects.

Also, you might want to consider that Macs now run on PC hardware and have done for a while now.

But excluding servers and desktop macs there is NO actual (by a measure of computer science) progress here.

Sorry I must be blind or completely miseducated etc.  Or at least tasteless, aren't I?

You really want me to answer that?