[sdiy] bootable linux cd

[Michael Zacherl]

Hi Glen/All,

Glen wrote:
> I'd like a stable OS that boots from non-volatile silicon memory, and which
> can't be altered by the software which runs on that OS. For example, I'm
> thinking along the lines of a memory card that has to be physically removed
> from the computer to change the OS, instead of an OS stored on vulnerable
> hard drive space, which could be altered by a rogue program or random power
> failure.

Ahh - you know this lone "NTLDR not found" message after the PC crashed 
and you desperately tried to (re)boot that thing? Had that 2 days ago.
I love it!  :-(((

> I know I'm dreaming, and I know it would need a huge amount of memory, but
> I think it would be better than what we have now.

Well, actually your dreams may come true. We are closer than one might 
think.
Compact Flash Cards and their respective IDE adapters allready have been 
mentioned.

When it comes to OS it's a bit more difficult - since the value are the 
apps and without apps ...

Linux has been mentioned - there are several more or less complex 
projects out there which specialise to run on a rather small (32MB or 
so) CF card.
But this is not what we are after.
Modern OS rely on being able to write data back on a media and (at least 
for the sake of minimum comfort) find them when booting up again.
So putting up a modern multi user and furthermore multitasking OS would 
require a lot more effort.

Fortunately a Unix-type system like Linux is quite modular and can be 
found in many flavors.

There's a german gentleman who wanted to have a non-destructable variant 
of the OS of his choice for his training calsses.
He managed to get software worth of 1.8GB on a single CD.
Go and see Klaus Knopper's website and give "Knoppix" a try IMO it's the 
most advanced version of a "Linux Live CD" you can find.

Since this all is Open Source as well (and Klaus is very serious about 
to take just open software) many spinoffs grew up in order to release 
versions for specific needs and incorporate apps which couldn't find 
place on the official "Knoppix" CD.

Although spread around the net the whole project is well documented and 
meanwhile international.
So language is not an issue.

Klaus uses an compressed disk image which he fits on the CD and mounts 
this image as a virtual device (cloop) when booting up.

So it's quite possible to generate a version of your wishes which 
contains the apps you want and fits a smaller CF card (e.g. 512MB) put 
the image and the kernel on it (very roughly spoken!) and boot from that 
instead of CD.
Everything runs in memory and is virtually not destroyable.
AND yes, you are able to mount another drive (whatever you want, it's 
Linux) and store data on it.

Also you can choose to install it on an ordinary hard drive and use it 
quite normal.
And since it's based on Debian GNU/Linux it's pretty open to what ever 
you want.

> Having the means to "lock-down" your executables would also be nice, but I
> wouldn't want each executable on a separate memory card, I'd just want to
> be able to physically set some sections of memory as read-only, by manually
> setting some physical switches myself. (Of course, this memory would be
> non-volatile as well.)

This you could do on a Linux system as well. Roughly, create a disk 
image, install whatever you want, unmount it and remount it read-only. 
Of course one has to take care of configuration files etc, but since 
most applications put their files in the user's home directory this 
should be achiveable.

IMHO you can do a lot of things this way (and many people, including 
myself, are taking advantage from this technology).

One last thing: when we think of e.g. Ataris (I own two of them) we 
think of "Megabytes" ... Now it's "Gigabytes", not to say almost 
"Terabytes".
That makes quite a difference - no multiuser for instance. Go figure.

But - OTOH - we can do it!  ;-)


Links of interest: http://www.knoppix.net/ (NZ spinoff in english language)
                   http://www.knopper.net/knoppix/ (the original site in 
german language)

    Michael.