Subject: Re: New pseudo bus, new device
To: Gary Thorpe <>
From: Wojciech Puchar <>
List: tech-kern
Date: 05/08/2002 07:38:08
> I am currently porting the ppc driver from FreeBSD to NetBSD (this is a low
> level driver for a AT-style parallel port chipset). While this work is
> progressing nicely (device can be probed, attached and configured for
> generic chipsets), it is still ongoing (specific chipset probes are not used
> right now). The ppc driver is MI as far as I can tell (currently this ppc
> device exists on the ISA bus, because that is my machines setup). I believe
> 'AT-style' parallel ports do exist on non-x86 machines (some alphas).

in which it is on ISA bus so should just work. (not sure how about
newer alphas)

> My main concern is the next major step in porting. I am at a loss on how to
> implement the ppbus 'pseudo' bus on top of this ppc device. The ppbus bus is
> used by almost all of the higher level drivers in the FreeBSD code, so
> reusing it is critical to port these drivers over (the drivers include lpt,
> iomega zip, ieee 1248, and PLIP). The reason this code is worth porting over
> is because NetBSD's current lpt support only supports centronics mode

implementing ECP/EPP etc. would be really nice.