I ran across this the other day.
I haven't been able to download it though.

http://reality.sgi.com/jamesb/gpasm/


Erik


Byron A Jeff wrote:
>
> >
> > On Tue, Jan 19, 1999 at 03:59:11PM -0600, Scott Newell wrote:
> > > Every once in a while, people discuss building PIC programmers or other
> > > hardware for use under Linux.  Now that I've got a Linux machine built up,
> > > I'm interested in using the PC's serial and parallel ports to interface to
> > > various devices, including some PIC projects.
> > >
> > > Does anyone have any good links or pointers to this kind of low-level
> > > device access?  (I'm comfortable with C++, and I really don't want to deal
> > > with the backwards AT&T-style x86 assembler syntax.)
> >
> > Two good books that cover this topic are:
> >
> > Linux Device Drivers by Alessandro Rubini (O'Reilly)
> >
> > and
> >
> > Linux Kernel Internals 2/E, Edited by Michael Beck (Addison-Wesley)
> >
> > In addition, the book
> >
> > Programming the Parallel Port; Interfacing the PC for Data
> > Acquisition and Process Control by Dhananjay V. Gadre (R&D Books)
> > http://www.amazon.com/exec/obidos/ASIN/0879305134/qid=916833059/sr=1-2/002-1
508759-9354633
> >
> > while mostly DOS-oriented, does have one chapter on
> > writing a Linux device driver for a parallel-port DAQ
> > application (beware, though, I found that this book
> > uses really funky jargon and diagrammatic conventions,
> > and is rife with typos. Still, if you can get past that,
> > there's a lot to learn from it).
> >
> > Most of what goes on at that level is typically
> > done in ANSI C, rather than C++.
>
> Bob,
>
> I'm thinking that the device driver level is a bit too far under the surface
> for what Scott wants to do. Both parallel and serial interfaces are accessible
> from the user level, the parallel port via the port interface, the serial
> ports via the already excellent serial driver.
>
> The Linux IO-Port programming Mini-Howto has more than enough information to
> get started. It can be found at:
>
> http://metalab.unc.edu/LDP/HOWTO/mini/IO-Port-Programming.html
>
> As another poster pointed out the low level interface code for the Linux
> based picprg by Brian Lane of Nexus computing:
>
> http://www.tatoosh.com/nexus/picpgmr.shtml
>
> is quite instructive.
>
> For the most part a Linux driver is required under one of three conditions:
>
> 1) Interrupts are involved.
> 2) Timing is critical.
> 3) Access must be managed to multiple simultaneous users/applications
>
> For simple stuff to the parallel port just use the user level I/O interface
> and make the application setuid root (because I/O require root access).
>
> BTW it may bear repeating (I haven't seen a Linux based environment discussion
> lately) that a Linux based PIC environment is doable. Last semester I had one
> of my students build a parallel port based 16[CF]84 programmer that uses
> Nexus Computers picprog to program, Timo Rossi's picasm located:
>
> http://www.iki.fi/trossi/pic/
>
> for an assembler, and I experimented with Scott Dattalo's gpsim simulator at:
>
> http://interstice.com/~sdattalo/gnupic/gpsim.html
>
> Which works really well but I think need in addition to the complicated node
> and waveform based pin simlation a really simple interface where you can just
> set a pin high or low for input.
>
> I banged out two quick light control projects over the holidays with this
> setup and was extremely happy to finally retire my PICSTART/DOSEMU based
> system that I was using earlier.
>
> Next on my project list is adding a second 16C84 based programmer with a
> serial interface which will program the rest of the PIC family.
>
> I'm looking forward to hearing more about PIC and Linux integration here on
> the list.
>
> BAJ