Subject: Re: panic: ptdi %x
To: None <>
From: Marc Boschma <>
List: current-users
Date: 03/18/1996 09:45:04
>In fact, there are lots of cool things that could be done with the

>1)  < good idea, no comment ;->

>2) Paging the kernel out, so a GENERIC kernel could be used, and after
>probe time just kick the unneeded drivers out of memory. What happened
>to lkm filesystems? I thought somebody was working on lkm msdosfs,cdfs,
>etc. Question: How hard would it be to have *all* filesystems lkmable,
>and be able to link them static if needed? I mean, on a regular boot
>bffs is certainly needed, but is nfs? The reverse: Why have bffs in
>a kernel that is nfs booted? Or why not be able to boot from an msdos
>disk, the way linux can?

I can see 'kicking unneeded drives out of memory' as being alittle hard.
Wouldn't you need to put them in continuous memory for that. lkm sounds a
nicer way to go. Do lkm's 'unload them selves, if they would be useless.
ie. for lkm device drivers, if the device isn't there.

I do like the independence of file system for booting. It would make the 
initial set up on some systems a lot easier.

>3)  < good idea, no comment ;->

>4) Having the kernel know what boot kernel image was used. How does
>OSF/1 do this? How about pass the name into the kernel as an arg on
>bootup (by the loader)? Then pass that name to libkvm. Then how do you
>deal with /dev/reload? Not 100% surefire, but it's an idea?

How about a really small file system with one file which maps to the kernel
via the inode. That way if you don't want it, it's not there, otherwise union
mount it in a 'well known' place.

>5) How about a kernel that could recognize certain errors at not being
>misson-critical panic attack problems, and just disable certain parts
>of the kernel on error? Like debugging an lkm filesystem: if the author
>screws up, no need to panic the system, just kill that lkm.

Or a memory failure in a non-kernel area of memory (just map it out after 
killing the process using it).

>6) Convince the Computer Science department here at NCSU that me working
>on this stuff is more worthwhile than me in classes designed for students 
>that touched their first computer as a freshman. If somebody could come
>up with a workable solution for this one, I'll be your friend for life ;).

Sorry on this one. I have a hard enough time here on those issues.

Marc B.