Subject: Using a serial console
To: None <>
From: Gordon W. Ross <>
List: port-sun3
Date: 08/21/1995 15:08:13
> From: Ben Walters <>
> Date: Mon, 21 Aug 1995 12:56:19 -0500 (CDT)

> Hi,
>   A friend and I have finally got NetBSD to the stage of acquiring it's
> kernel from a Linux box and booting (after quite a lot of work and
> frustration with tftpd :) but after the kernel begins to boot we get
> the message to the effect of starting console with kdb0.  Our machine
> is a 3/60 and has the onboard mono framebuffer but no keyboard/monitor
> attached (we're using a serial console on ttya).   How do we tell NetBSD
> to use that instead of the framebuffer/keyboard?
> Ben

[ This is a good one for the FAQ.  Anyone keeping track? -gwr ]

At the PROM monitor prompt, do this:
	q1f 10
which says: "patch eeprom byte 0x1f to the value 0x10"

That byte determines the console location.  The values are:

#define	EE_CONS_BW		0x00	/* - On-board B&W / keyboard	*/
#define	EE_CONS_TTYA		0x10	/* - serial port A		*/
#define	EE_CONS_TTYB		0x11	/* - serial port B		*/
#define	EE_CONS_COLOR		0x12	/* - Color FB / keyboard	*/
#define	EE_CONS_P4OPT		0x20	/* - Option board on P4		*/

The above info can be found in src/sys/arch/sun3/include/eeprom.h
(or /usr/include/machine/eeprom.h on a sun3 running NetBSD).