NAME
console —
i386 console interface
SYNOPSIS
options CONSDEVNAME=string
options CONADDR=integer
options CONSPEED=integer
options CONS_OVERRIDE
options CONMODE=integer
DESCRIPTION
The “console” device is used for
kernel printf
messages and accesses to the
/dev/console character special
device in user mode. It is attached to a hardware interface at boot time
controlled by options in the kernel configuration file, or information passed
by the boot loader.
Bootblocks from
NetBSD 1.4 or newer select their console
device from a compiled-in list, and then pass their choice of console device
and console parameters to the kernel.
As of
NetBSD 1.5, the
consdev
bootblock command allows changing the console device on-the-fly.
The kernel will use the same console device as the bootblock; no special kernel
configuration is required.
To override the bootblock's choice of console, or to use a serial kernel console
with older bootblocks, you must specify kernel config-file options to override
the information passed by the bootblock. The current option choices are:
-
-
- - the standard PC keyboard
and display
- (with either the “pc” or the
wscons(4) driver)
-
-
- - standard PC serial
ports
- (with com(4)
driver)
The available
kernel configuration options are:
- options CONSDEVNAME=string
- specifies the name of the console device. Valid values
are “pc” for the pc keyboard / display (default) and
“com” for a serial port.
- options CONADDR=integer
- sets the base address for the serial console port
(default: 0x3f8).
- options CONSPEED=integer
- sets the baudrate for the serial console (default:
9600).
- options CONS_OVERRIDE
- causes console information passed by the bootloader to be
ignored and the settings specified by the three options above (or the
defaults) to be used. Default behaviour is to use the settings from the
bootloader if present, and to use option / default values only if no
information was passed.
- options CONMODE=integer
- allows to specify terminal control flags. The argument is
a “cflag” value, see
termios(4) for details.
Default is
(CREAD
| CS8
|
HUPCL)
(8N1). This option takes always effect,
because mode settings are not passed by the bootloader.
FILES
-
-
- /dev/console
-
- /sys/arch/i386/conf/CONFIG
-
EXAMPLES
options
CONSDEVNAME="\"com\"",CONADDR=0x2f8,CONSPEED=57600
SEE ALSO
config(1),
tty(4),
boot(8),
boot_console(8)
BUGS
The console device is chosen early in system startup regardless if the specified
driver / device is present in the system configuration file. If the driver
asked for by the bootloader or “
options
CONSDEVNAME” is not configured into the system, a panic is caused.
Because there is no console device, no explaining message will be printed. If
the driver is present, but the specific device instance not, kernel printf
will work, but
/dev/console becomes a dummy.