From: Daniel Lang <dl@leo.org> To: freebsd-hackers@freebsd.org, freebsd-quetions@freebsd.org Subject: Kernel Console speed Message-ID: <20010502140423.B91287@atrbg11.informatik.tu-muenchen.de>
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Dear People,
I have configured a couple of machines to use
the serial console. Now with some machines, the
console speed cannot be set correctly.
I have read the appropriate chapters in the handbook,
and I getting the serial console working at all, is
not a problem. Just the speed setting does not work
at _some_ machines.
As far as I understand it, there are several components
that interact as (serial) console:
- boot2
- loader
- the kernel
- the getty (if a getty is configured at the console device)
My problems only apply to the kernel, not to the bootstrap,
and the getty intially uses, what the kernel used.
What I did:
set BOOT_COMCONSOLE_SPEED=38400 in /etc/make.conf
set options CONSPEED=38400 in KERNEL
compiled and installed kernel and new bootstrap (with disklabel).
changed /etc/ttys to use std.38400 as argument to getty.
further:
set machdep.conspeed=38400 in /boot/loader.conf
I've checked with kgdb the constants in the debugging kernel,
that in /sys/isa/sio.c:sysctl_machdep_comdefaultrate()
comdefaultrate is indeed 38400.
The bootstraps works with 38400, (both boot2 and loader),
but as soon as the kernel boots, it switches back to 9600.
If the system is up, I can change the sysctl parameter:
sysctl -w machdep.conspeed=38400
back to 38400, which works then (it also worked
automaticalle if I place this in /etc/sysctl.conf).
But I seem to have no chance to make it actually boot with that speed,
so that the booting messages of the kernel can be viewed from
the console-server.
I run 4.3-STABLE on the box. The strange things is, that it
works on another machine, but not on two other ones.
All run the same release, all are i386 PCs with 16550A UARTs.
The hardware is of course capable of running at different
speeds than 9600, since the bootstrap runs at 38400 and
a running system can be set to it, too.
The hardware is very different though:
Working boxes: Athlon 700 on Asus A7V
Not working ones: Dell PowerEdge 4/200: 4xPPro 200 SMP,
(with chipset info) Intel 82454KX/GX (Orion) host to PCI bridge
Intel 82375EB PCI-EISA bridge
Thanks and Best regards,
Daniel
--
IRCnet: Mr-Spock - Agartim billiard bumba m'abdul in papejim twista
- rumba rock n rolla. Leik'ab mai. Spirzon Heroin se'osit gaula. -
- Marijuana esit gaula. Haschisch. Opis. -
*Daniel Lang * dl@leo.org * +49 89 289 25735 * http://www.leo.org/~dl/*
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