Subject: Re: How to identify NetBSD ELF kernel?
To: Chris G. Demetriou <>
From: Pavel Roskin <>
List: current-users
Date: 10/15/1999 19:13:44
Hello, Chris, Jason and Ignatios!

> Jason Thorpe <> writes:
> >  > IMHO it's impractical to duplicate all features of GNU GRUB in every
> >  > bootloader. I mean support for 4 filesystems, filename completion,
> >  > forthcoming netboot support, forthcoming IsaPNP support (if I don't
> >  > upgrade my AWE64 before that :-))
> > 
> > NetBSD's bootloader supports a large number of filesystems, too:
> > 
> > 	FFS
> > 	LFS
> > 	ISO-9660
> > ...EXT2FS would be easy, and MSDOSFS is probably not far off.

Well, NetBSD's bootloader supports those filesystems, but how about
booting Linux from ext2fs?

Do you mean that there should be separate bootloaders for every OS, but
with similar features? IMHO it just duplicates the code and the bugs.

> Actually, i've done an MSDOSFS (FAT-12 and FAT-16 only, though) for a
> separate framework that's largely compatible with libsa (i lifted the
> libsa FFS code for use with it, with minor mods, so... 8-), that
> should be made freely available before too long...
> and don't forget USTAR "fs" support, as well as things like gziped
> binary support, and all those wonderful network load methods (do TFTP
> and NFS count as "file systems")?  8-)

I would very much prefer if not only NetBSD users could use your code.

> >  > Can anybody give me a fresh kernel? I mean it should be compiled with the
> >  > latest tools and contain the Elf Note section. Sorry, I cannot afford 
> >  > trashing my NetBSD installation right now.
> > 
> > NetBSD kernels don't have the note sections in them.  Only userland binaries.

That's bad. See below.

> Further, it's not obvious why you'd even want them in the kernel,
> since things like the load addresses are communicated nicely via the
> ELF headers.

Yes, provided that the bootloader supports only one OS.
The current bootloader for NetBSD doesn't boot FreeBSD, because FreeBSD
kernels require different format of boot parameters.

> Actually, maybe i can imagine that you'd want notes there to provide
> firmware/bootloader information that's not in the executable headers,
> but I can't think of anything like that off-hand...

I want to know _how_, not _what_
What I want to know how do I determine that the given kernel accepts
boot parameters in NetBSD style, be it NetBSD or whatever else.

Pavel Roskin