Subject: Re: Zilog ESCC (Z85230) support for i386?
To: Felix Deichmann <f.dei@web.de>
From: Bill Studenmund <wrstuden@netbsd.org>
List: port-i386
Date: 06/03/2003 17:51:05
On Tue, 3 Jun 2003, Felix Deichmann wrote:

> Hi.
>
> I've obtained a TeleBit NetBlazer PN2, which has a Zilog ESCC (Z85230)
> as serial controller. The connectors are 2 x DB25. I will try to boot
> NetBSD on this box as soon as I have fixed its damage.
>
> Is the ESCC supported for i386? If not, how difficult would it be to
> implement it?
> Can the ESCC provide a serial console?

Shouldn't be hard to support as an 8530. While I played with ESCC support,
I never ended up adding it to the MI driver.

You'll want to look at the zsc and zstty drivers. The zsc controls the
whole chip, and the zstty driver adds a tty on top. We do this since you
can also have other things, like direct-connect keyboards or mice
connected.

Once you get it working as an SCC, we can look at adding ESCC support. The
main thing AFAICT is the deeper transmit & receive queues. Writing reg 14'
is a pain, though.

Take care,

Bill