Subject: Re: console boot floppies for 1.5.1? (would be nice)
To: None <,>
From: Ross Harvey <>
List: port-alpha
Date: 04/02/2001 19:44:17
> >Ideally, it would be nice if a 3000/300 class machine could come up
> >running on the monitor rather than being forced into a serial >terminal.
> >That would seem to require a second set of boot floppies and a >kern.tgz
> >with both kernels available, and some way to force either at the tail
> >end of the install.
> I did this for 1.5 and I never did get to test if it was possible to have a 
> common install/generic kernel that could support tcwscons features without 
> breaking existing console support for other machines. I'm a bit short on 
> non-3000 series Alphas around here that I can test such things on.
> It'd be nice if someone else could try building even just an install kernel 
> with the Turbochannel options included and seeing if it breaks other 
> machines. If nobody else is up for it, I'll take a shot, but I'm not in love 
> with the idea of doing all that compiling again on a 120Mhz 3000/300.
> (I wonder if they'd notice if I borrowed one of the DS10s over easter ... 
> hmm, there's a thought ...)
> But yes, count me in as one person who thinks that being able to boot a 3000 
> from standard install binaries without a serial cable is a good idea.

Most of the issues with (and reasons for) the TCWSCONS special-case predate
my time here, but I think I vaguely know what the issue is.

First, the scorecard:

	TCWSCONS => zsc => dev/ic/z8530sc.c
	GENERIC => scc => alpha/tc/scc.c

It's not a bad interaction with other consoles, I think it's a problem with
the serial driver. IIRC the TC alphas have a funny botch, I think some of
the modem control lines for the two serial channels are swizzled between
the two connectors, or some awful thing like that.

The alpha-only arch/alpha/tc/scc.c is hacked to do only one thing, serial
console, but at least to do it correctly. If we unhack it, it will do what
some of you want, frame buffer installs, but other things will break.

The MI dev/ic/z8530sc.c has no alpha hacks, so it doesn't torch your
framebuffer install, but it also doesn't know about the alpha modem wackyness.

The "right fix", I guess, is: fix zsc with some kind of a graceful attachment
indicating swizzled modem lines. In the "we hack it right now anyway dept",
an alternative is to just switch GENERIC and INSTALL to zsc right now. This
would help people doing framebuffer installs and complicate life for people
who really do want a serial console or SLIP or PPP installs. And thirdly,
a duplicate install disk setup would help, sure.

Fortunately, this would only affect the TC alphas.  None of the PCI/ISA
alphas use any 8530-type serial.  (Hmm, but what about the 4100, 8200, and

Disclaimer: there are other people around here who are much more familiar
with this issue than I am; I certainly apologize if my summary got off
track somwhere.