Subject: Re: TTY virtualization driver
To: None <>
From: Bill Studenmund <>
List: tech-kern
Date: 01/22/2002 16:12:20
On Tue, 22 Jan 2002 wrote:

> > No, the puc0 is a multifunction device that has ns16550 controllers
> > embedded in it.  The problem is when you have different types of serial
> > controllers.  For example:
> >
> > com0	at pci dev ? function ?
> > sab0	at pci dev ? function ?
> > zs0	at sbus slot ?
> >
> > Where both of those are mutually exclusive and have the same physical
> > location in the machine.  Since they have different major numbers you
> can you explain this?
> two drivers for SAME port?!?!?!?!

?? Where is the problem?

The confusion is that Sun changed the hardware they used on different
machines. So you look at the box, and see a serial port. Depending on if
it's an Ultra this or a Sparc that, it has different chips connected to
it, so different drivers attach.

Take care,