Why should I use Amiga?

[Hans_]

From a user point of view, I'd say that Amiga OS is fast and responsive, even on low-specced machines. For developers, the underlying design looks cleaner to me, and more logical. Also, seeing as development has been lagging behind, there are plenty of software projects available for you to have a go at.

AROS is not multi-user. There is a multi-user filesystem for the Amiga but AFAIK it doesn't work with Amiga OS4. Looking at the OS structures, multi-user support was planned, but never implemented. I guess that it's still on the to-do list.

For Amiga OS4 you're just going to have to wait to buy hardware. Once a motherboard is available, you should be able to piece together a machine the same way you do with an ordinary x86 PC. Just note that there aren't hardware drivers available for every piece of hardware out there. Genesi's hardware will not run Amiga OS4.

As you're into coding, utilitybase.com is a good forum for asking questions regarding the OS structure and how to use various components.


Hans

[Hans_]

anon123 wrote:
So amiga DOES have multiuser support, it just isn't fully used?

Sort of. The MultiUserFilesystem was a 3rd party file-system that implemented users/groups and login functionality. Multi-user support should really be integrated into the OS fully (into AmigaDOS in particular). Unfortunately there is no Amiga OS4 native version yet.

I meant build a box for OS4, which I think runs on PPC, or does it have a really special set up or something? Could someone explain the hardware aspect of modern amiga's to me, it's really bizarre  :-?

Yes the hardware situation is bizarre. Right now, Amiga Inc. insists that only licensed PowerPC hardware is allowed to run Amiga OS4. Amiga Inc. and Genesi hate each other for historical reasons and won't cooperate with each other. Therefore the Pegasos sadly won't run Amiga OS4, even though there's no technical reason why it can't. It would be fairly trivial for them to write the necessary drivers/bootstrap code for those machines.

Currently Amiga OS4 runs on the Amigaone hardware (I have one of these) which is no longer available for purchase. It will be available to classic Amiga owners (such as the A1200/A4000) that have PowerPC accelerators plugged in.

I'll look into Amiga forever. When do you expect the SAM440EP to be ready?

The hardware is pretty much done (see here. We're just waiting for Amiga Inc. to give them a license. Hopefully they're already working on writing drivers for it so that Amiga OS4 can run on it.

NOTE: AmigaForever is for the classic Amiga only, that's up to Amiga OS3.9.

What is AmigaDOS? Is it the shell? The underlying system/kernel? A separate OS?

AmigaDOS is the disk operating system for the Amiga. It's a sub-component of the OS that handles file access (files including pipes and other streaming devices).

Hans

[Hans_]

SamuraiCrow wrote:
Just to clarify, the Pegasos 1 and 2 are discontinued hardware, and the Pegasos 3 only supports PowerPC Linux due to multicore processor usage.  AmigaOS doesn't support SMP currently, nor does MorphOS.

It the Pegasos 3 already available? Even without SMP support, you could always disable one core until SMP support is added.

Hans

[Hans_]

@Piru

Piru wrote:
AmigaOS does not have multiuser support of any usable kind. Anyone trying to suggest multiuser.library and muFS are just kidding themselves.

IMO muFS is kind of pointless exercise, as there is no memory protection anyway.

What does multi-user support have to do with memory protection? Multi-user functionality is just supposed to be a method of making sure that user's have their own environment and don't get at each others files. MuFS does that.

MuFS is not secure in any way; to access a whole partition you only need to change the partition back to FFS and you have unrestricted access to the whole drive. However, I see that as a security issue, not multi-user functionality. If you're really serious about protecting your data you should  use encryption and back up your files regularly.

Having said all that, it'd be nice if someone integrated secure multi-user support to the OS. Like you said, a few prerequisites are required first.

Hans

[Hans_]

Piru wrote:

What does multi-user support have to do with memory protection? Multi-user functionality is just supposed to be a method of making sure that user's have their own environment and don't get at each others files. MuFS does that.

Without memory protection any user can poke some magic location in the filesystem and make all files accessable.

That's a security issue, not a multi-user filesystem issue. The file-system does provide multi-user file access restrictions, even if it's not that hard to circumvent them.  It's not secure enough for critical systems by any means, but it's good enough to prevent non-hackers from accessing/deleting the wrong files.

From the multiuser README:

Code: [Select]

Introduction
------------

MultiUser allows you to create a *IX-like environment where several users live
together  in harmony, unable to delete each others files, unable to read those
private  love-letters  of  other  users.   And  this even if several users are
working on the machine at the same time (on a terminal hooked up to the serial
port)

People without a valid login ID and password won't be able to access files you
have made private with MultiUser.  If you make all files private (not readable
for others), the only useful thing they could do, is boot from a floppy.
MuFS doesn't give any of the other true multiuser benefits, such as user specific preferences, or separated user home directories.

User specific preferences or separated home directories is not the job of a file-system, that's something that the desktop part of the OS should provide. Some people have been doing that with scripts.

So what is left? Supposedly separate file owner info and access permissions, which are trivially hacked.

Yep. That's about it.

muFS is even more pointless as muFS user/group info isn't synced with the user/group stuff in the TCP/IP stack. So you have two sets of users and groups to maintain, and you can easily get them out of sync.

I didn't know about this (never actually needed MuFS). That is definitely a problem. The Roadshow networking stack for OS4 doesn't have users/groups (at least, not in the preferences). I'd say that users/groups handling should be part of AmigaDOS, not the TCP/IP stack.

MuFS is pointless.

I'd say, ALMOST pointless. ;-)

Way back in 2000 some people were going to work on MuFS 2 which was supposed to address the security issues and AmiTCP integration. Sadly, there's been no news from them in 6 years. The current Amiga OS4 release has a certain amount of memory protection that could be used (e.g., you can allocate private memory), so that could be used (for OS4 only). It should really be built in to Amiga DOS though.

Hans

[Hans_]

@Piru

Piru wrote:

The current Amiga OS4 release has a certain amount of memory protection that could be used (e.g., you can allocate private memory), so that could be used (for OS4 only).

That wouldn't work (as protection) anyway, as user is always running with "root" privileges. So any malware could just use whatever is needed make the memory writable, poke in the patch, and then write protect the memory again.

For multiuser to be really secure, the underlying system must be built from ground to have proper access control. Basically this would require total OS rewrite, basing it on some BSD (unix) like kernel.

I said private memory, not read-only memory. Private memory should, in theory, only be accessable by the task that created it. Therefore, only the task that created it should be able to change it's protection status. I have no idea if this is actually the case in the current implementation.

Point taken though.

Hans