Subject: Re: Kernel doc -- Jolitz 386BSD book?
To: Hauke Fath <>
From: Curt Sampson <>
List: tech-kern
Date: 10/06/1996 12:04:24
On Sun, 6 Oct 1996, Hauke Fath wrote:

> I am on my way writing a mac68k floppy driver and in desperate need of
> information about the device driver framework (autoconfig and such); the
> Red Book only touches these issues at the surface, and any books about
> writing device drivers seem to concentrate on SysV (and 4.3BSD VAX
> heritage :-( ). At the moment, I am frequently 'making phantoms I can
> later chase' (Magazine) because I lack understanding.

There isn't, unfortunately, much documentation that can help with
this sort of thing. After being an observer for a year or so, and
reading all of the books I can get my hands on, I'm making my first
foray into kernel hacking by trying to figure out why the ep driver
is broke on PCI cards. I'd be sunk by now were it not for Wright
and Stevens' _TCP/IP Illustrated, Volume 2_, which disects the
4.4BSD networking code line by line and explains it all.

That book, however, is over a thousand pages long, looks to be
about 2-3 man-years of work, and covers only TCP/IP networking
code, and at that not the device-dependent portions. I'd estimate
that we'd need two more like this to cover the other important
parts of the kernel. So I don't think we're going to be seeing much
documentation at this level soon.

However, section 9 of the manual is a darn good start. It might
also be worthwhile to try to convince various NetBSD luminaries to
write papers covering, in general detail, bits of the kernel or
the configuration system or whatever, and then putting them in a
NetBSD equivalant of the SMM (the KHM?). 

At any rate, don't be discouraged. It's a long hard slog, but it
looks to me that the rewards are worthwhile. After a year, I'm not
even at your level of understanding, but I know beauty and I know
a good thing when I see it.


Curt Sampson		Info at
Internet Portal Services, Inc.	
Vancouver, BC   (604) 257-9400		De gustibus, aut bene aut nihil.