Path: utzoo!mnetor!uunet!oddjob!hao!husc6!encore!paradis
From: paradis@encore.UUCP (Jim Paradis)
Newsgroups: comp.os.minix
Subject: Re: Why no ispeed/ospeed??
Message-ID: <2740@encore.UUCP>
Date: 1 Mar 88 22:56:50 GMT
References: <213@gould.doc.ic.ac.uk>
Sender: news@husc6.harvard.edu
Reply-To: paradis@encore.UUCP (Jim Paradis)
Distribution: comp
Organization: The Whizzo Chocolate Company
Lines: 40

In article <213@gould.doc.ic.ac.uk> lmjm@doc.ic.ac.uk (Lee McLoughlin) writes:
>[I was] quite suprised to find that there was no sg_ispeed and sg_ospeed
>fields in the sgttyb structure.  Indeed there is no baud rate control
>anywhere that I can find.

Actually, sg_ispeed and sg_ospeed ARE defined in /usr/include/sgtty.h in
the MINIX 1.1 distribution, but they're not used in that distribution
(read on)

>How are you supposed to achieve this?
>Is sg_i/ospeed coming?
>Why is it currently missing?

It's currently missing because MINIX as it comes out of the box lacks
a serial TTY driver.  Its tty driver only supports the IBM-PC keyboard
and video adapter.  Baud rates have no meaning there.  It's also missing
because the way ioctl currently works is to pack as much of the
parameters as it can into a MINIX message structure (overloading like
crazy at times) and send it off... and there's simply no room in the
message structure for the ispeed and ospeed fields.

In case you didn't catch it, I posted a serial tty driver to the net
sometime back and have been working (off and on) on bug fixes and
enhancements ever since; one of my enhancements was to re-do ioctl such
that it passes the address of the ioctl structure to the kernel, and
the kernel copies the structure in and out.  This way, ioctl structures
may be made arbitrarily large.

(For those who are waiting:  Yes, I'm working on all this stuff, but
I have a day-job that I occasionally have to do real work at too 8-).
It's coming, it's coming... if someone's willing to pay me $60K/yr to
hack MINIX full-time I'd be more than glad to do so 8-) 8-) 8-)  )


   +----------------+  Jim Paradis                  linus--+
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Well, what's the pleasure in THAT??!!