Greetings--may I be of service?

[Dennis W. Tokarski]

Hi Adi, Hi Ralph.

My name is Dennis Tokarski. I run a little one-man consulting shop in
Ann Arbor, Michigan, USA. Mostly my work is software development for
real time and embedded systems, much of that driver writing, and almost
all of it for QNX (at least for the past 6 years or so).

However, I am finding Linux a compelling alternative for some
applications. The learning curve has been a bit steep, and have found
Beck & Co's book "Linux Kernel Internals" very helpful. I am now
part way through Rubini's very excellent "Linux Device Drivers".

Recently a client approached me about putting together a small footprint
Linux package for use in their embedded product. The hardware isn't
really constrained (Pentium/133 at least, 64MB RAM, all the usual PC
desktop facilities like SVGA, etc), but they do have a peculiar
requirement in they aren't allowed to use a hard drive, or any kind
of alterable media for program storage.

In a previous incarnation of this project, we've booted QNX4 from ROM,
with all the ancillary applications loaded from a ROM disk. I'd like to
work my way toward a similar capability using Linux.

PeeWeeLinux seems to be the best starting point. I've spent a couple of
days looking for small-footprint distributions. There are lots out
there, but as Ralph noted in a January 26 post about YASL, some have
just sort of faded away. I didn't find anyone else using the 2.2 kernel,
it's all 2.0 as far as I could tell. Nor does anyone appear to have
their project as cleanly organized as yours, or set up to use as current
a development platform as current as RH 6.1, which is what I'm running
in my office. By the way, while I've downloaded your latest (0.20) I've
not taken it for a test drive. I expect to have that pleasure later
today or tomorrow.

The one common thread amongst all the small Linices seems to be that
they boot from floppy, or more rarely as in your case, Disk On Chip.
I've used the DOC parts before with QNX. They're OK, but in my current
project the fact that they behave like writeable disks is a problem.

Adi, I think you mentioned in a readme file somewhere something about
writing an open source file system driver. Have you done anything with
that idea yet?

If not, perhaps this is where I can make a contribution in the near
future. I was thinking of using the existing dos/fat file system as a
starting point, then seeing what I could carve out and otherwise modify
to suit my customer's requirements. The result would have to be
suitable for use with a disk image on ROM (hopefully using compression
to save space), and could probably be used with battery backed SRAM
(which we also have on our hardware).

The other thing I'm looking to do is solve the boot-from-ROM problem.
Nobody has done this so far as I can tell. My current thought is to
locate a modified version of lilo in one of our user bios ROMs. It would
have hard-wired knowledge of a ROM address where it would find an
essentially conventional Linux boot image which it would relocate to low
RAM and start up. After that it would be business as usual. This is
basically what we did with QNX, so the idea is at least workable.
Ultimately what we'd like to achieve is an execute-from-ROM ability, but
I'm most definitely not knowledgeable enough about Lines yet to tackle
that one.

So, do think these sorts of things would be useful additions to your
project? Of course, any advice and moral support you can provide while I
do the dog work will be greatly appreciated.

You've put together a nice package. I look forward to using it and
giving something back.

   Regards,

   Dennis Tokarski
   PolTec Electronics
   921 S. Seventh St.
   Ann Arbor, MI  48103
   (734) 994-0212
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