Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

fixes and cleanup, submitted by Greg A. Woods per PR port-i386/6695

Browse Source 
(minimally edited)
This commit is contained in:
drochner 1999-02-21 15:59:18 +00:00
parent 918dfd95e1
commit b968de922b
1 changed files with 105 additions and 76 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

181
share/man/man8/man8.i386/boot_console.8
View File

@ -1,98 +1,127 @@
.\" $NetBSD: boot_console.8,v 1.3 1998/02/25 12:30:13 drochner Exp $
.\" $NetBSD: boot_console.8,v 1.4 1999/02/21 15:59:18 drochner Exp $
.\"
.Dd September 30, 1997
.Dd December 31, 1998
.Os
.Dt BOOT_CONSOLE 8 i386
.Sh NAME
.Nm boot_console
.Nd selection of a console device in the i386 bootloader
.\"
.Sh DESCRIPTION
The i386 bootloader selects a console device for its user interaction
and passes information about it to the
The
.Nx
kernel. The selection process is controlled by bootloader compile-time
i386 bootloader selects a console device for its user interaction and
passes information about it to the
.Nx
kernel. The selection process is controlled by bootloader compile-time
options and system setup at the bootloader startup time.
.Pp
The compile-time options (to set in the bootloader's
.Dq Makefile
) are:
.\"
.Ss Serial Console Options
The compile-time options (to be set in the booter's
.Dq Makefile )
are:
.Bl -ohang
.It Cd SUPPORT_SERIAL
enables support for serial input / output. If not set, the standard PC
keyboard / display is always used as console device and the following
options are meaningless.
.It Cd DIRECT_SERIAL
.It Dv Sy SUPPORT_SERIAL= Ns Fa policy
enables support for serial input / output. By default this option is
not set and the standard PC keyboard and display are always used as the
console device. See
.Dq Em "Console selection Policy"
below for valid values of
.Fa policy .
.It Dv Sy DIRECT_SERIAL
causes direct hardware access to be used for serial input / output.
With this option, software handshake (XON/XOFF) is used for
flow control. Without this option, BIOS functions are employed for
serial port handling, which require hardware handshake lines to
be completely wired.
.It Cd CONSPEED=integer
sets the baudrate for the serial console. This option has only an
effect together with the
.Dq Cd DIRECT_SERIAL
option above. Otherwise, the default setting of 9600 baud is used.
.It Cd COMCONS_KEYPRESS
If console autoselection is used (see below), require a character
input within 1 second after a space character is sent to the serial
line for a serial console device to be selected. If not set, only a simple
function check is done (and the hardware handshake is checked
if
.Dq Cd DIRECT_SERIAL
is not defined).
With this option, software handshake (XON/XOFF) is used for flow
control. Without this option, BIOS functions are employed for serial
port handling, which require hardware handshake lines to be completely
wired.
.It Dv Sy CONSPEED= Ns Fa integer
sets the baud-rate for the serial console. This option has only an
effect when used in combination with the
.Dq Dv DIRECT_SERIAL
option above, otherwise, the default setting of 9600 baud is used. The
value of
.Fa integer
must be something that makes sense as a serial port baud rate.
.It Dv Sy COMCONS_KEYPRESS
Require a character input within seven(7) seconds from serial console
device to be selected.
.El
The actual policy for the console selection is determined by the
argument to the console initialization function
.Fn initio int
which is called early in the bootloader's
.Fn main
function. The following are available:
.\"
.Ss Console Selection Policy
The actual policy for the console selection is determined by the value
of
.Dv Dq SUPPORT_SERIAL
The following options are available:
.Bl -ohang
.It Fa CONSDEV_PC
Use the standard PC keyboard / display as console.
.It Fa CONSDEV_COM0 Li ... Fa CONSDEV_COM3
Use the serial port with the corresponding BIOS number as
console. If the port is not known to the BIOS, it falls back to
.Dq Fa CONSDEV_PC
\& .
(Note1: This feature can be deliberately used for console
selection if the BIOS allows to disable serial ports.)
(Note2: This works with the
.Dq Cd DIRECT_SERIAL
option too.)
.It Fa CONSDEV_AUTO
Auto-select the console. First the serial ports known to the BIOS
are probed. If output of a (space) character to the port succeeds,
and the conditions described under
.Dq Cd COMCONS_KEYPRESS
above are fulfilled, the port is used as console. If no serial port
.It Dv Em CONSDEV_PC
Force use of the standard PC keyboard and display as the console.
.It Dv Em CONSDEV_COM0 Li ... Dv Em CONSDEV_COM3
Use the serial port with the corresponding BIOS number as the console.
No output is attempted to the selected serial port. If the port is not
known to the BIOS, it falls back to
.Dq Dv CONSDEV_PC .
(Note: This feature can be deliberately used for console selection if
the serial ports have been disabled in the BIOS.)
.It Dv Em CONSDEV_COM0KBD Li ... Dv Em CONSDEV_COM3KBD
If the port is known to the BIOS, and output of a character to the port
succeeds (and if
.Dq Dv DIRECT_SERIAL
is defined the RS-232
.Dq "modem ready"
status is on after the character is output), and the conditions
described under
.Dq Dv COMCONS_KEYPRESS
above are fulfilled, the port is used as console. If the port is not
known to the BIOS, it falls back to
.Dq Dv CONSDEV_PC .
.It Dv Em CONSDEV_AUTO
Auto-select the console. All serial ports known to the BIOS are probed
in sequence. If output of a character to the port succeeds (and if
.Dq Dv DIRECT_SERIAL
is defined the RS-232
.Dq "modem ready"
status is on after the character is output), and the conditions
described under
.Dq Dv COMCONS_KEYPRESS
above are fulfilled, the port is used as console. If no serial port
passes the check,
.Dq Fa CONSDEV_PC
is used. The progress of the selection process is shown at the PC display
as digits corresponding to the serial port number currently probed.
.Dq Dv CONSDEV_PC
is used. The progress of the selection process is shown at the PC
display as digits corresponding to the serial port number currently
probed.
.El
.\"
.Sh FILES
.Bl -tag -width xxx
.It Pa /src/sys/arch/i386/stand/{bios,dos,net}boot/Makefile
.It Pa /src/sys/arch/i386/stand/{bios,dos,net}boot/main.c
.Bl -tag -width /sys/arch/i386/stand/{bios,dos,net}boot/Makefile
.It Pa /sys/arch/i386/stand/{bios,dos,net}boot/Makefile
compile time options for the boot programs.
.El
.\"
.Sh SEE ALSO
.Xr console 4 ,
.Xr boot 8
.\"
.Sh BUGS
There is generally no non-volatile storage available on the
PC platform. This requires autoselection methods which can
be inconvinient and / or unstable in some situations. The selection
policy should be adapted to the local hardware configuration, which
might require code changes.
The value of
.Dv SERIAL_POLICY
should be settable through a boot configuration option. However
traditionally there was no non-volatile storage available on the PC
platform. This requires console auto-selection methods which can be
inconvenient and / or unstable in some situations. The selection policy
should be adapted to the local hardware configuration, which might
require code changes. (Some BIOS versions, particularly those used on
large servers and in embedded and single-board industrial computers,
have integrated support for serial consoles. The boot loader should
query for these settings if possible.)
.Pp
The serial communication parameters (bytesize, parity, stopbits)
are not setable. In any case,
.Dq 8N1
is used.
The serial communication parameters (byte-size, parity, stop-bits) are
not settable (either at compile time or run time). The default
parameters are
.Dq "8 N 1" .
.Pp
The baud rate is not settable when using BIOS I/O. It should be
settable at compile time with
.Dv Dq CONSPEED
just as it is when using
.Dv Dq DIRECT_SERIAL .
The default speed is 9600 baud (the maximum for BIOS I/O).