4d87b291ad
user to interrupt autoboot process at all. Currently, even when `autoboot_delay' is set to 0, loader(8) still allows autoboot process to be interrupted by pressing any key on the console when the loader reads kernel and modules from the disk. In some cases (i.e. untrusted environment) such behaviour is highly indesirable and user should not be allowed to interfere with the autoboot process at all. Sponsored by: PBXpress Inc. MFC after: 3 days
933 lines
23 KiB
Groff
933 lines
23 KiB
Groff
.\" Copyright (c) 1999 Daniel C. Sobral
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|
.\" All rights reserved.
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.\"
|
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.\" Redistribution and use in source and binary forms, with or without
|
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.\" modification, are permitted provided that the following conditions
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.\" are met:
|
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.\" 1. Redistributions of source code must retain the above copyright
|
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.\" notice, this list of conditions and the following disclaimer.
|
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.\" 2. Redistributions in binary form must reproduce the above copyright
|
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd October 15, 2004
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.Dt LOADER 8
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|
.Os
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|
.Sh NAME
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|
.Nm loader
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|
.Nd kernel bootstrapping final stage
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|
.Sh DESCRIPTION
|
|
The program called
|
|
.Nm
|
|
is the final stage of
|
|
.Fx Ns 's
|
|
kernel bootstrapping process.
|
|
On IA32 (i386) architectures, it is a
|
|
.Pa BTX
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|
client.
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|
It is linked statically to
|
|
.Xr libstand 3
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|
and usually located in the directory
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|
.Pa /boot .
|
|
.Pp
|
|
It provides a scripting language that can be used to
|
|
automate tasks, do pre-configuration or assist in recovery
|
|
procedures.
|
|
This scripting language is roughly divided in
|
|
two main components.
|
|
The smaller one is a set of commands
|
|
designed for direct use by the casual user, called "builtin
|
|
commands" for historical reasons.
|
|
The main drive behind these commands is user-friendliness.
|
|
The bigger component is an
|
|
.Tn ANS
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|
Forth compatible Forth interpreter based on FICL, by
|
|
.An John Sadler .
|
|
.Pp
|
|
During initialization,
|
|
.Nm
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|
will probe for a console and set the
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|
.Va console
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|
variable, or set it to serial console
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|
.Pq Dq comconsole
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|
if the previous boot stage used that.
|
|
Then, devices are probed,
|
|
.Va currdev
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|
and
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|
.Va loaddev
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|
are set, and
|
|
.Va LINES
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|
is set to 24.
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|
Next,
|
|
.Tn FICL
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|
is initialized, the builtin words are added to its vocabulary, and
|
|
.Pa /boot/boot.4th
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|
is processed if it exists.
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|
No disk switching is possible while that file is being read.
|
|
The inner interpreter
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|
.Nm
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|
will use with
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|
.Tn FICL
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|
is then set to
|
|
.Ic interpret ,
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|
which is
|
|
.Tn FICL Ns 's
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|
default.
|
|
After that,
|
|
.Pa /boot/loader.rc
|
|
is processed if available, and, failing that,
|
|
.Pa /boot/boot.conf
|
|
is read for historical reasons.
|
|
These files are processed through the
|
|
.Ic include
|
|
command, which reads all of them into memory before processing them,
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|
making disk changes possible.
|
|
.Pp
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|
At this point, if an
|
|
.Ic autoboot
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|
has not been tried, and if
|
|
.Va autoboot_delay
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|
is not set to
|
|
.Dq NO
|
|
(not case sensitive), then an
|
|
.Ic autoboot
|
|
will be tried.
|
|
If the system gets past this point,
|
|
.Va prompt
|
|
will be set and
|
|
.Nm
|
|
will engage interactive mode.
|
|
Please note that historically even when
|
|
.Va autoboot_delay
|
|
is set to
|
|
.Dq 0
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|
user will be able to interrupt autoboot process by pressing some key
|
|
on the console while kernel and modules are being loaded. In some
|
|
cases such behaviour may be undesirable, to prevent it set
|
|
.Va autoboot_delay
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|
to
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|
.Dq -1 ,
|
|
in this case
|
|
.Nm
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|
will engage interactive mode only if
|
|
.Ic autoboot
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|
has failed.
|
|
.Sh BUILTIN COMMANDS
|
|
In
|
|
.Nm ,
|
|
builtin commands take parameters from the command line.
|
|
Presently,
|
|
the only way to call them from a script is by using
|
|
.Pa evaluate
|
|
on a string.
|
|
If an error condition occurs, an exception will be generated,
|
|
which can be intercepted using
|
|
.Tn ANS
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|
Forth exception handling
|
|
words.
|
|
If not intercepted, an error message will be displayed and
|
|
the interpreter's state will be reset, emptying the stack and restoring
|
|
interpreting mode.
|
|
.Pp
|
|
The builtin commands available are:
|
|
.Pp
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|
.Bl -tag -width Ds -compact
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|
.It Ic autoboot Op Ar seconds Op Ar prompt
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|
Proceeds to bootstrap the system after a number of seconds, if not
|
|
interrupted by the user.
|
|
Displays a countdown prompt
|
|
warning the user the system is about to be booted,
|
|
unless interrupted by a key press.
|
|
The kernel will be loaded first if necessary.
|
|
Defaults to 10 seconds.
|
|
.Pp
|
|
.It Ic bcachestat
|
|
Displays statistics about disk cache usage.
|
|
For depuration only.
|
|
.Pp
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|
.It Ic boot
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|
.It Ic boot Ar kernelname Op Cm ...
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|
.It Ic boot Fl flag Cm ...
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|
Immediately proceeds to bootstrap the system, loading the kernel
|
|
if necessary.
|
|
Any flags or arguments are passed to the kernel, but they
|
|
must precede the kernel name, if a kernel name is provided.
|
|
.Pp
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|
.Em WARNING :
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|
The behavior of this builtin is changed if
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|
.Xr loader.4th 8
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|
is loaded.
|
|
.Pp
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|
.It Ic echo Xo
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|
.Op Fl n
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|
.Op Aq message
|
|
.Xc
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|
Displays text on the screen.
|
|
A new line will be printed unless
|
|
.Fl n
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|
is specified.
|
|
.Pp
|
|
.It Ic heap
|
|
Displays memory usage statistics.
|
|
For debugging purposes only.
|
|
.Pp
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|
.It Ic help Op topic Op subtopic
|
|
Shows help messages read from
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|
.Pa /boot/loader.help .
|
|
The special topic
|
|
.Em index
|
|
will list the topics available.
|
|
.Pp
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|
.It Ic include Ar file Op Ar
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|
Process script files.
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|
Each file, in turn, is completely read into memory,
|
|
and then each of its lines is passed to the command line interpreter.
|
|
If any error is returned by the interpreter, the include
|
|
command aborts immediately, without reading any other files, and
|
|
returns an error itself (see
|
|
.Sx ERRORS ) .
|
|
.Pp
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|
.It Ic load Xo
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|
.Op Fl t Ar type
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|
.Ar file Cm ...
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|
.Xc
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|
Loads a kernel, kernel loadable module (kld), or file of opaque
|
|
contents tagged as being of the type
|
|
.Ar type .
|
|
Kernel and modules can be either in a.out or ELF format.
|
|
Any arguments passed after the name of the file to be loaded
|
|
will be passed as arguments to that file.
|
|
Currently, argument passing does not work for the kernel.
|
|
.Pp
|
|
.It Ic ls Xo
|
|
.Op Fl l
|
|
.Op Ar path
|
|
.Xc
|
|
Displays a listing of files in the directory
|
|
.Ar path ,
|
|
or the root directory if
|
|
.Ar path
|
|
is not specified.
|
|
If
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|
.Fl l
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|
is specified, file sizes will be shown too.
|
|
.Pp
|
|
.It Ic lsdev Op Fl v
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|
Lists all of the devices from which it may be possible to load modules.
|
|
If
|
|
.Fl v
|
|
is specified, more details are printed.
|
|
.Pp
|
|
.It Ic lsmod Op Fl v
|
|
Displays loaded modules.
|
|
If
|
|
.Fl v
|
|
is specified, more details are shown.
|
|
.Pp
|
|
.It Ic more Ar file Op Ar
|
|
Display the files specified, with a pause at each
|
|
.Va LINES
|
|
displayed.
|
|
.Pp
|
|
.It Ic pnpscan Op Fl v
|
|
Scans for Plug-and-Play devices.
|
|
This is not functional at present.
|
|
.Pp
|
|
.It Ic read Xo
|
|
.Op Fl t Ar seconds
|
|
.Op Fl p Ar prompt
|
|
.Op Va variable
|
|
.Xc
|
|
Reads a line of input from the terminal, storing it in
|
|
.Va variable
|
|
if specified.
|
|
A timeout can be specified with
|
|
.Fl t ,
|
|
though it will be canceled at the first key pressed.
|
|
A prompt may also be displayed through the
|
|
.Fl p
|
|
flag.
|
|
.Pp
|
|
.It Ic reboot
|
|
Immediately reboots the system.
|
|
.Pp
|
|
.It Ic set Ar variable
|
|
.It Ic set Ar variable Ns = Ns Ar value
|
|
Set loader's environment variables.
|
|
.Pp
|
|
.It Ic show Op Va variable
|
|
Displays the specified variable's value, or all variables and their
|
|
values if
|
|
.Va variable
|
|
is not specified.
|
|
.Pp
|
|
.It Ic unload
|
|
Remove all modules from memory.
|
|
.Pp
|
|
.It Ic unset Va variable
|
|
Removes
|
|
.Va variable
|
|
from the environment.
|
|
.Pp
|
|
.It Ic \&?
|
|
Lists available commands.
|
|
.El
|
|
.Ss BUILTIN ENVIRONMENT VARIABLES
|
|
The
|
|
.Nm
|
|
has actually two different kinds of
|
|
.Sq environment
|
|
variables.
|
|
There are ANS Forth's
|
|
.Em environmental queries ,
|
|
and a separate space of environment variables used by builtins, which
|
|
are not directly available to Forth words.
|
|
It is the latter type that this section covers.
|
|
.Pp
|
|
Environment variables can be set and unset through the
|
|
.Ic set
|
|
and
|
|
.Ic unset
|
|
builtins, and can have their values interactively examined through the
|
|
use of the
|
|
.Ic show
|
|
builtin.
|
|
Their values can also be accessed as described in
|
|
.Sx BUILTIN PARSER .
|
|
.Pp
|
|
Notice that these environment variables are not inherited by any shell
|
|
after the system has been booted.
|
|
.Pp
|
|
A few variables are set automatically by
|
|
.Nm .
|
|
Others can affect the behavior of either
|
|
.Nm
|
|
or the kernel at boot.
|
|
Some options may require a value,
|
|
while others define behavior just by being set.
|
|
Both types of builtin variables are described below.
|
|
.Bl -tag -width bootfile
|
|
.It Va acpi_load
|
|
Unset this to disable automatic loading of the ACPI module.
|
|
See also
|
|
.Va hint.acpi.0.disabled
|
|
in
|
|
.Xr device.hints 5 .
|
|
.It Va autoboot_delay
|
|
Number of seconds
|
|
.Ic autoboot
|
|
will wait before booting.
|
|
If this variable is not defined,
|
|
.Ic autoboot
|
|
will default to 10 seconds.
|
|
.Pp
|
|
If set to
|
|
.Dq NO ,
|
|
no
|
|
.Ic autoboot
|
|
will be automatically attempted after processing
|
|
.Pa /boot/loader.rc ,
|
|
though explicit
|
|
.Ic autoboot Ns 's
|
|
will be processed normally, defaulting to 10 seconds delay.
|
|
.Pp
|
|
If set to
|
|
.Dq 0
|
|
no delay will inserted, but user still will be able to interrupt
|
|
.Ic autoboot
|
|
process and escape into the interactive mode by pressing some key
|
|
on the console while kernel and
|
|
modules are being loaded.
|
|
.Pp
|
|
If set to
|
|
.Dq -1
|
|
no delay will inserted and
|
|
.Nm
|
|
will engange interactive mode only if
|
|
.Ic autoboot
|
|
has failed for some reason.
|
|
.It Va boot_askname
|
|
Instructs the kernel to prompt the user for the name of the root device
|
|
when the kernel is booted.
|
|
.It Va boot_cdrom
|
|
Instructs the kernel to try to mount the root file system from CD-ROM.
|
|
.It Va boot_ddb
|
|
Instructs the kernel to start in the DDB debugger, rather than
|
|
proceeding to initialize when booted.
|
|
.It Va boot_gdb
|
|
Selects gdb-remote mode for the kernel debugger by default.
|
|
.It Va boot_multicons
|
|
Enables multiple console support in the kernel early on boot.
|
|
In a running system, console configuration can be manipulated
|
|
by the
|
|
.Xr conscontrol 8
|
|
utility.
|
|
.It Va boot_serial
|
|
Force the use of a serial console even when an internal console
|
|
is present.
|
|
.It Va boot_single
|
|
Prevents the kernel from initiating a multi-user startup; instead,
|
|
a single-user mode will be entered when the kernel has finished
|
|
device probing.
|
|
.It Va boot_verbose
|
|
Setting this variable causes extra debugging information to be printed
|
|
by the kernel during the boot phase.
|
|
.It Va bootfile
|
|
List of semicolon-separated search path for bootable kernels.
|
|
The default is
|
|
.Dq Li kernel .
|
|
.It Va console
|
|
Defines the current console.
|
|
.It Va currdev
|
|
Selects the default device.
|
|
Syntax for devices is odd.
|
|
.It Va init_path
|
|
Sets the list of binaries which the kernel will try to run as the initial
|
|
process.
|
|
The first matching binary is used.
|
|
The default list is
|
|
.Dq Li /sbin/init:/sbin/oinit:/sbin/init.bak:/rescue/init:/stand/sysinstall .
|
|
.It Va interpret
|
|
Has the value
|
|
.Dq Li OK
|
|
if the Forth's current state is interpreting.
|
|
.It Va LINES
|
|
Define the number of lines on the screen, to be used by the pager.
|
|
.It Va module_path
|
|
Sets the list of directories which will be searched for modules
|
|
named in a load command or implicitly required by a dependency.
|
|
The default value for this variable is
|
|
.Dq Li /boot/kernel;/boot/modules .
|
|
.It Va num_ide_disks
|
|
Sets the number of IDE disks as a workaround for some problems in
|
|
finding the root disk at boot.
|
|
This has been deprecated in favor of
|
|
.Va root_disk_unit .
|
|
.It Va prompt
|
|
Value of
|
|
.Nm Ns 's
|
|
prompt.
|
|
Defaults to
|
|
.Dq Li "${interpret}" .
|
|
If variable
|
|
.Va prompt
|
|
is unset, the default prompt is
|
|
.Ql > .
|
|
.It Va root_disk_unit
|
|
If the code which detects the disk unit number for the root disk is
|
|
confused, e.g.\& by a mix of SCSI and IDE disks, or IDE disks with
|
|
gaps in the sequence (e.g.\& no primary slave), the unit number can
|
|
be forced by setting this variable.
|
|
.It Va rootdev
|
|
By default the value of
|
|
.Va currdev
|
|
is used to set the root file system
|
|
when the kernel is booted.
|
|
This can be overridden by setting
|
|
.Va rootdev
|
|
explicitly.
|
|
.El
|
|
.Pp
|
|
Other variables are used to override kernel tunable parameters.
|
|
The following tunables are available:
|
|
.Bl -tag -width Va
|
|
.It Va hw.physmem
|
|
Limit the amount of physical memory the system will use.
|
|
By default the size is in bytes, but the
|
|
.Cm k , K , m , M , g
|
|
and
|
|
.Cm G
|
|
suffixes
|
|
are also accepted and indicate kilobytes, megabytes and gigabytes
|
|
respectively.
|
|
An invalid suffix will result in the variable being ignored by the
|
|
kernel.
|
|
.It Va hw.pci.host_start_mem , hw.acpi.host_start_mem
|
|
When not otherwise constrained, this limits the memory start
|
|
address.
|
|
The default is 0x80000000 and should be set to at least size of the
|
|
memory and not conflict with other resources.
|
|
Typically, only systems without PCI bridges need to set this variable
|
|
since PCI bridges typically constrain the memory starting address
|
|
(and the variable is only used when bridges do not constrain this
|
|
address).
|
|
.It Va hw.pci.enable_io_modes
|
|
Enable PCI resources which are left off by some BIOSes or are not
|
|
enabled correctly by the device driver.
|
|
Tunable value set to ON (1) by default, but this may cause problems
|
|
with some peripherals.
|
|
.It Va kern.maxusers
|
|
Set the size of a number of statically allocated system tables; see
|
|
.Xr tuning 7
|
|
for a description of how to select an appropriate value for this
|
|
tunable.
|
|
When set, this tunable replaces the value declared in the kernel
|
|
compile-time configuration file.
|
|
.It Va kern.ipc.nmbclusters
|
|
Set the number of mbuf clusters to be allocated.
|
|
The value cannot be set below the default
|
|
determined when the kernel was compiled.
|
|
Modifies
|
|
.Dv NMBCLUSTERS .
|
|
.It Va kern.ipc.nsfbufs
|
|
Set the number of
|
|
.Xr sendfile 2
|
|
buffers to be allocated.
|
|
Overrides
|
|
.Dv NSFBUFS .
|
|
.It Va kern.maxswzone
|
|
Limits the amount of KVM to be used to hold swap
|
|
meta information, which directly governs the
|
|
maximum amount of swap the system can support.
|
|
This value is specified in bytes of KVA space
|
|
and defaults to around 70MBytes.
|
|
Care should be taken
|
|
to not reduce this value such that the actual
|
|
amount of configured swap exceeds 1/2 the
|
|
kernel-supported swap.
|
|
The default 70MB allows
|
|
the kernel to support a maximum of (approximately)
|
|
14GB of configured swap.
|
|
Only mess around with
|
|
this parameter if you need to greatly extend the
|
|
KVM reservation for other resources such as the
|
|
buffer cache or
|
|
.Dv NMBCLUSTERS .
|
|
Modifies
|
|
.Dv VM_SWZONE_SIZE_MAX .
|
|
.It Va kern.maxbcache
|
|
Limits the amount of KVM reserved for use by the
|
|
buffer cache, specified in bytes.
|
|
The default maximum is 200MB.
|
|
This parameter is used to
|
|
prevent the buffer cache from eating too much
|
|
KVM in large-memory machine configurations.
|
|
Only mess around with this parameter if you need to
|
|
greatly extend the KVM reservation for other resources
|
|
such as the swap zone or
|
|
.Dv NMBCLUSTERS .
|
|
Note that
|
|
the NBUF parameter will override this limit.
|
|
Modifies
|
|
.Dv VM_BCACHE_SIZE_MAX .
|
|
.It Va machdep.disable_mtrrs
|
|
Disable the use of i686 MTRRs (x86 only).
|
|
.It Va net.inet.tcp.tcbhashsize
|
|
Overrides the compile-time set value of
|
|
.Dv TCBHASHSIZE
|
|
or the preset default of 512.
|
|
Must be a power of 2.
|
|
.It Va vm.kmem_size
|
|
Sets the size of kernel memory (bytes).
|
|
This overrides the value determined when the kernel was compiled.
|
|
Modifies
|
|
.Dv VM_KMEM_SIZE .
|
|
.El
|
|
.Ss BUILTIN PARSER
|
|
When a builtin command is executed, the rest of the line is taken
|
|
by it as arguments, and it is processed by a special parser which
|
|
is not used for regular Forth commands.
|
|
.Pp
|
|
This special parser applies the following rules to the parsed text:
|
|
.Pp
|
|
.Bl -enum
|
|
.It
|
|
All backslash characters are preprocessed.
|
|
.Bl -bullet
|
|
.It
|
|
\eb , \ef , \er , \en and \et are processed as in C.
|
|
.It
|
|
\es is converted to a space.
|
|
.It
|
|
\ev is converted to
|
|
.Tn ASCII
|
|
11.
|
|
.It
|
|
\ez is just skipped.
|
|
Useful for things like
|
|
.Dq \e0xf\ez\e0xf .
|
|
.It
|
|
\e0xN and \e0xNN are replaced by the hex N or NN.
|
|
.It
|
|
\eNNN is replaced by the octal NNN
|
|
.Tn ASCII
|
|
character.
|
|
.It
|
|
\e" , \e' and \e$ will escape these characters, preventing them from
|
|
receiving special treatment in Step 2, described below.
|
|
.It
|
|
\e\e will be replaced with a single \e .
|
|
.It
|
|
In any other occurrence, backslash will just be removed.
|
|
.El
|
|
.It
|
|
Every string between non-escaped quotes or double-quotes will be treated
|
|
as a single word for the purposes of the remaining steps.
|
|
.It
|
|
Replace any
|
|
.Li $VARIABLE
|
|
or
|
|
.Li ${VARIABLE}
|
|
with the value of the environment variable
|
|
.Va VARIABLE .
|
|
.It
|
|
Space-delimited arguments are passed to the called builtin command.
|
|
Spaces can also be escaped through the use of \e\e .
|
|
.El
|
|
.Pp
|
|
An exception to this parsing rule exists, and is described in
|
|
.Sx BUILTINS AND FORTH .
|
|
.Ss BUILTINS AND FORTH
|
|
All builtin words are state-smart, immediate words.
|
|
If interpreted, they behave exactly as described previously.
|
|
If they are compiled, though,
|
|
they extract their arguments from the stack instead of the command line.
|
|
.Pp
|
|
If compiled, the builtin words expect to find, at execution time, the
|
|
following parameters on the stack:
|
|
.D1 Ar addrN lenN ... addr2 len2 addr1 len1 N
|
|
where
|
|
.Ar addrX lenX
|
|
are strings which will compose the command line that will be parsed
|
|
into the builtin's arguments.
|
|
Internally, these strings are concatenated in from 1 to N,
|
|
with a space put between each one.
|
|
.Pp
|
|
If no arguments are passed, a 0
|
|
.Em must
|
|
be passed, even if the builtin accepts no arguments.
|
|
.Pp
|
|
While this behavior has benefits, it has its trade-offs.
|
|
If the execution token of a builtin is acquired (through
|
|
.Ic '
|
|
or
|
|
.Ic ['] ) ,
|
|
and then passed to
|
|
.Ic catch
|
|
or
|
|
.Ic execute ,
|
|
the builtin behavior will depend on the system state
|
|
.Bf Em
|
|
at the time
|
|
.Ic catch
|
|
or
|
|
.Ic execute
|
|
is processed!
|
|
.Ef
|
|
This is particularly annoying for programs that want or need to
|
|
handle exceptions.
|
|
In this case, the use of a proxy is recommended.
|
|
For example:
|
|
.Dl : (boot) boot ;
|
|
.Sh FICL
|
|
.Tn FICL
|
|
is a Forth interpreter written in C, in the form of a forth
|
|
virtual machine library that can be called by C functions and vice
|
|
versa.
|
|
.Pp
|
|
In
|
|
.Nm ,
|
|
each line read interactively is then fed to
|
|
.Tn FICL ,
|
|
which may call
|
|
.Nm
|
|
back to execute the builtin words.
|
|
The builtin
|
|
.Ic include
|
|
will also feed
|
|
.Tn FICL ,
|
|
one line at a time.
|
|
.Pp
|
|
The words available to
|
|
.Tn FICL
|
|
can be classified into four groups.
|
|
The
|
|
.Tn ANS
|
|
Forth standard words, extra
|
|
.Tn FICL
|
|
words, extra
|
|
.Fx
|
|
words, and the builtin commands;
|
|
the latter were already described.
|
|
The
|
|
.Tn ANS
|
|
Forth standard words are listed in the
|
|
.Sx STANDARDS
|
|
section.
|
|
The words falling in the two other groups are described in the
|
|
following subsections.
|
|
.Ss FICL EXTRA WORDS
|
|
.Bl -tag -width wid-set-super
|
|
.It Ic .env
|
|
.It Ic .ver
|
|
.It Ic -roll
|
|
.It Ic 2constant
|
|
.It Ic >name
|
|
.It Ic body>
|
|
.It Ic compare
|
|
This is the STRING word set's
|
|
.Ic compare .
|
|
.It Ic compile-only
|
|
.It Ic endif
|
|
.It Ic forget-wid
|
|
.It Ic parse-word
|
|
.It Ic sliteral
|
|
This is the STRING word set's
|
|
.Ic sliteral .
|
|
.It Ic wid-set-super
|
|
.It Ic w@
|
|
.It Ic w!
|
|
.It Ic x.
|
|
.It Ic empty
|
|
.It Ic cell-
|
|
.It Ic -rot
|
|
.El
|
|
.Ss FREEBSD EXTRA WORDS
|
|
.Bl -tag -width XXXXXXXX
|
|
.It Ic \&$ Pq --
|
|
Evaluates the remainder of the input buffer, after having printed it first.
|
|
.It Ic \&% Pq --
|
|
Evaluates the remainder of the input buffer under a
|
|
.Ic catch
|
|
exception guard.
|
|
.It Ic .#
|
|
Works like
|
|
.Ic .
|
|
but without outputting a trailing space.
|
|
.It Ic fclose Pq Ar fd --
|
|
Closes a file.
|
|
.It Ic fkey Pq Ar fd -- char
|
|
Reads a single character from a file.
|
|
.It Ic fload Pq Ar fd --
|
|
Processes a file
|
|
.Em fd .
|
|
.It Ic fopen Pq Ar addr len mode Li -- Ar fd
|
|
Opens a file.
|
|
Returns a file descriptor, or \-1 in case of failure.
|
|
The
|
|
.Ar mode
|
|
parameter selects whether the file is to be opened for read access, write
|
|
access, or both.
|
|
The constants
|
|
.Dv O_RDONLY , O_WRONLY ,
|
|
and
|
|
.Dv O_RDWR
|
|
are defined in
|
|
.Pa /boot/support.4th ,
|
|
indicating read only, write only, and read-write access, respectively.
|
|
.It Xo
|
|
.Ic fread
|
|
.Pq Ar fd addr len -- len'
|
|
.Xc
|
|
Tries to read
|
|
.Em len
|
|
bytes from file
|
|
.Em fd
|
|
into buffer
|
|
.Em addr .
|
|
Returns the actual number of bytes read, or -1 in case of error or end of
|
|
file.
|
|
.It Ic heap? Pq -- Ar cells
|
|
Return the space remaining in the dictionary heap, in cells.
|
|
This is not related to the heap used by dynamic memory allocation words.
|
|
.It Ic inb Pq Ar port -- char
|
|
Reads a byte from a port.
|
|
.It Ic key Pq -- Ar char
|
|
Reads a single character from the console.
|
|
.It Ic key? Pq -- Ar flag
|
|
Returns
|
|
.Ic true
|
|
if there is a character available to be read from the console.
|
|
.It Ic ms Pq Ar u --
|
|
Waits
|
|
.Em u
|
|
microseconds.
|
|
.It Ic outb Pq Ar port char --
|
|
Writes a byte to a port.
|
|
.It Ic seconds Pq -- Ar u
|
|
Returns the number of seconds since midnight.
|
|
.It Ic tib> Pq -- Ar addr len
|
|
Returns the remainder of the input buffer as a string on the stack.
|
|
.It Ic trace! Pq Ar flag --
|
|
Activates or deactivates tracing.
|
|
Does not work with
|
|
.Ic catch .
|
|
.El
|
|
.Ss FREEBSD DEFINED ENVIRONMENTAL QUERIES
|
|
.Bl -tag -width Ds
|
|
.It arch-i386
|
|
.Ic TRUE
|
|
if the architecture is IA32.
|
|
.It arch-alpha
|
|
.Ic TRUE
|
|
if the architecture is AXP.
|
|
.It FreeBSD_version
|
|
.Fx
|
|
version at compile time.
|
|
.It loader_version
|
|
.Nm
|
|
version.
|
|
.El
|
|
.Ss SYSTEM DOCUMENTATION
|
|
.Sh FILES
|
|
.Bl -tag -width /boot/defaults/loader.conf -compact
|
|
.It Pa /boot/loader
|
|
.Nm
|
|
itself.
|
|
.It Pa /boot/boot.4th
|
|
Additional
|
|
.Tn FICL
|
|
initialization.
|
|
.It Pa /boot/boot.conf
|
|
.Nm
|
|
bootstrapping script.
|
|
Deprecated.
|
|
.It Pa /boot/defaults/loader.conf
|
|
.It Pa /boot/loader.conf
|
|
.It Pa /boot/loader.conf.local
|
|
.Nm
|
|
configuration files, as described in
|
|
.Xr loader.conf 5 .
|
|
.It Pa /boot/loader.rc
|
|
.Nm
|
|
bootstrapping script.
|
|
.It Pa /boot/loader.help
|
|
Loaded by
|
|
.Ic help .
|
|
Contains the help messages.
|
|
.El
|
|
.Sh EXAMPLES
|
|
Boot in single user mode:
|
|
.Pp
|
|
.Dl boot -s
|
|
.Pp
|
|
Load the kernel, a splash screen, and then autoboot in five seconds.
|
|
Notice that a kernel must be loaded before any other
|
|
.Ic load
|
|
command is attempted.
|
|
.Bd -literal -offset indent
|
|
load kernel
|
|
load splash_bmp
|
|
load -t splash_image_data /boot/chuckrulez.bmp
|
|
autoboot 5
|
|
.Ed
|
|
.Pp
|
|
Set the disk unit of the root device to 2, and then boot.
|
|
This would be needed in a system with two IDE disks,
|
|
with the second IDE disk hardwired to wd2 instead of wd1.
|
|
.Bd -literal -offset indent
|
|
set root_disk_unit=2
|
|
boot /kernel
|
|
.Ed
|
|
.Pp
|
|
See also:
|
|
.Bl -tag -width /usr/share/examples/bootforth/X
|
|
.It Pa /boot/loader.4th
|
|
Extra builtin-like words.
|
|
.It Pa /boot/support.4th
|
|
.Pa loader.conf
|
|
processing words.
|
|
.It Pa /usr/share/examples/bootforth/
|
|
Assorted examples.
|
|
.El
|
|
.Sh ERRORS
|
|
The following values are thrown by
|
|
.Nm :
|
|
.Bl -tag -width XXXXX -offset indent
|
|
.It 100
|
|
Any type of error in the processing of a builtin.
|
|
.It -1
|
|
.Ic Abort
|
|
executed.
|
|
.It -2
|
|
.Ic Abort"
|
|
executed.
|
|
.It -56
|
|
.Ic Quit
|
|
executed.
|
|
.It -256
|
|
Out of interpreting text.
|
|
.It -257
|
|
Need more text to succeed -- will finish on next run.
|
|
.It -258
|
|
.Ic Bye
|
|
executed.
|
|
.It -259
|
|
Unspecified error.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr libstand 3 ,
|
|
.Xr loader.conf 5 ,
|
|
.Xr tuning 7 ,
|
|
.Xr boot 8 ,
|
|
.Xr btxld 8
|
|
.Sh STANDARDS
|
|
For the purposes of ANS Forth compliance, loader is an
|
|
.Bf Em
|
|
ANS Forth System with Environmental Restrictions, Providing
|
|
.Ef
|
|
.Bf Li
|
|
.No .( ,
|
|
.No :noname ,
|
|
.No ?do ,
|
|
parse, pick, roll, refill, to, value, \e, false, true,
|
|
.No <> ,
|
|
.No 0<> ,
|
|
compile\&, , erase, nip, tuck
|
|
.Ef
|
|
.Em and
|
|
.Li marker
|
|
.Bf Em
|
|
from the Core Extensions word set, Providing the Exception Extensions
|
|
word set, Providing the Locals Extensions word set, Providing the
|
|
Memory-Allocation Extensions word set, Providing
|
|
.Ef
|
|
.Bf Li
|
|
\&.s,
|
|
bye, forget, see, words,
|
|
\&[if],
|
|
\&[else]
|
|
.Ef
|
|
.Em and
|
|
.Li [then]
|
|
.Bf Em
|
|
from the Programming-Tools extension word set, Providing the
|
|
Search-Order extensions word set.
|
|
.Ef
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
first appeared in
|
|
.Fx 3.1 .
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
The
|
|
.Nm
|
|
was written by
|
|
.An Michael Smith Aq msmith@FreeBSD.org .
|
|
.Pp
|
|
.Tn FICL
|
|
was written by
|
|
.An John Sadler Aq john_sadler@alum.mit.edu .
|
|
.Sh BUGS
|
|
The
|
|
.Ic expect
|
|
and
|
|
.Ic accept
|
|
words will read from the input buffer instead of the console.
|
|
The latter will be fixed, but the former will not.
|