Subject: Re: Install NetBSD over the top of Linux
To: None <chammer@hermes.hrz.uni-bielefeld.de>
From: Ken Hornstein <kenh@cmf.nrl.navy.mil>
List: current-users
Date: 06/16/1996 23:39:19
>> >1. Major and minor device numbers dont conform to any standard.
>> >   (is there any?)
>
>What i mean is that i think it would be useful to have the harddisks on
>NetBSD-Amiga have the same Major and minor numbers as NetBSD-i386,
>NetBSD-sparc,..

I could see the reasoning for that, but since you can't use filesystems on
machines that have a different endianness (ie - you can't use an i386
NetBSD filesytem on an Amiga or a Mac), I'm not sure it would be worth
the effort.  How would you resolve the case where different systems have
different devices?  I suppose you could make one master conf.c for all
architectures.

>I dont mind to change the NetBSD-Amiga device numbers to i386 style..
>Of course it is difficult to do it with all devices as same are uniq on
>some platforms but it should be possible to find a way to get NetBSD-Amiga 
>boot on a NetBSD-Mac Harddisk after replacing /netbsd by the NetBSD-Amiga 
>version. As i understand it it is necceassary for this to match the
>device numbers to the same hardware devices on the different platforms.
>And at least the major number distribution seems to be completely
>arbitrary on the different NetBSD ports and Unixes in genereal.

Okay, at the same time you replace /netbsd, why don't you put new devices
in /dev?

>> >2. NetBSD does not understand ext2fs of Linux
>> 
>> Well, there are actually about a billion reasons it wouldn't work :-)  These
>> probably include:
>> 
>> - Lilo may not know how to load a netbsd executable
>
>why? NetBSD-i386 has to boot to NetBSD somehow.. how?
>Is there a tool similar to lilo that allows to boot netbsd?
>What makes it impossible to replace lilo by something that allows NetBSD to
>boot? Could lilo be modified to even boot NetBSD kernels copied to /vmlinuz?

What boots NetBSD are the NetBSD boot blocks.  They don't understand ext2fs
either, so you'd need to either change them to understand ext2fs (which would
be a LOT of work), or reformat the filesystem as a UFS filesystem (and if
you're going to do that, you might as well install NetBSD).

>> - NetBSD doesn't know how to run Linux binaries (you might be able to get
>>   by with Linux binary emulation, but I'm sure lots of things won't work).
>
>I was under the impression that NetBSD's Linux emulation has improved very
>well. What exactly it the problem? 
>init,fsck,mount,..?
>Would it be possible to replace these parts and make it then work?

I believe Laine Stump convered this better than I ever could.  I'd just like
to point out that if you replace init, fsck, mount, you'll also need to
replace /etc/rc and rc.local, and then you'll need all the boot binaries
that NetBSD needs (along with NetBSD shared libraries, ld.so, etc etc ...)

>> >And to try to get help directly for my problem:
>> >Is there any filesystem that NetBSD and Linux know both and
>> >that would help to do my migration to NetBSD?
>> 
>> Well, there's always MSDOSFS.  I don't know of any others.
>
>Unfortunatly this means to introduce a non transparent way to 
>interpret msdos files as special files. How does linux do this? 
>I heard it is able to boot from msdos fs. 

What you're referring to is the ability to run a special program from MS-DOS
and have it boot Linux.  I believe there is even a way to boot a Linux
kernel that is stored in a MS-DOS partition.  But as I understand it, you
still need a Linux installation to work -- that "booting from MS-DOS"
only gets the kernel loaded.

The same technology exists for FreeBSD, and I believe someone did it for
NetBSD as well.  Again, this doesn't help you much.

>> I think you might be able to do an NFS-mount off of one of the install
>> floppies ... but if you can do that, why not just ftp the installation
>> sets?
>
>perhaps anybody out there knows something about this more exact?!
>I cant see what ftping helps me if i dont have the space to hold the
>NetBSD distribution on the msdos partition. 

No, I mean when you get the filesystem initialized and have booted off of
your NetBSD kernel on your HD, you could ftp the installation media from
that point.  I believe this is even mentioned in the install notes.

--Ken