Whitespace-only changes: apply accepted line breaking style as a
pre-cursor to other markup changes. Accepted in principle by the author.
This commit is contained in:
Sheldon Hearn
parent
37f653195d
commit
0c74e83819
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=61943
@ -38,22 +38,24 @@ The program called
|
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is the final stage of FreeBSD's kernel bootstrapping process.
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On IA32 (i386) architectures, it is a
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.Pa BTX
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client. It is linked statically to
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client.
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It is linked statically to
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.Xr libstand 3
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and usually located in the directory
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.Pa /boot .
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.Pp
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It provides a scripting language that can be used to
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automate tasks, do pre-configuration or assist in recovery
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procedures. This scripting language is roughly divided in
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two main components. The smaller one is a set of commands
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procedures.
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This scripting language is roughly divided in
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two main components.
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The smaller one is a set of commands
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designed for direct use by the casual user, called "builtin
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commands" for historical reasons. The main drive behind
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these commands is user-friendlyness. The bigger component
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is an
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commands" for historical reasons.
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The main drive behind these commands is user-friendlyness.
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The bigger component is an
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.Tn ANS
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Forth compatible Forth interpreter based on
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ficl, by
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Forth compatible Forth interpreter based on ficl, by
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.An John Sadler .
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.Pp
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During initialization,
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@ -62,18 +64,21 @@ 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,
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if the previous boot stage used that.
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Then, devices are probed,
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.Va currdev
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and
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.Va loaddev
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are set, and
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.Va LINES
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is set to 24 . Next,
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is set to 24.
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Next,
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.Tn FICL
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is initialized, the builtin words are added to its vocabulary, and
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.Pa /boot/boot.4th
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will be processed if it exists. No disk switching is possible while
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that file is being read. The inner interpreter
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will be processed if it exists.
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No disk switching is possible while that file is being read.
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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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@ -81,12 +86,13 @@ is then set to
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.Ic interpret ,
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which is
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.Tn FICL Ns 's
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default. After that,
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default.
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After that,
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.Pa /boot/loader.rc
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is processed if available, and, failing that,
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.Pa /boot/boot.conf
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will be read for historical reasons. These files are processed
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through the
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will be read for historical reasons.
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These files are processed through the
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.Ic include
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command, which read all of them into memory before processing them,
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making disk changes possible.
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@ -99,21 +105,25 @@ is not set to
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.Dq NO
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(not case sensitive), then an
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.Ic autoboot
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will be tried. If the system gets past this point,
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will be tried.
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If the system gets past this point,
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.Va prompt
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will be set and
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.Nm
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will engage interactive mode.
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.Sh BUILTIN COMMANDS
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.Nm Loader Ns No 's
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builtin commands take its parameters from the command line. Presently,
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builtin commands take its parameters from the command line.
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Presently,
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the only way to call them from a script is by using
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.Pa evaluate
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on a string. If an error condition occurs, an exception will be
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generated, which can be intercepted using
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on a string.
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If an error condition occurs, an exception will be generated,
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which can be intercepted using
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.Tn ANS
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Forth exception handling
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words. If not intercepted, an error message will be displayed and
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words.
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If not intercepted, an error message will be displayed and
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the interpreter's state will be reset, emptying the stack and restoring
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interpreting mode.
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.Pp
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@ -122,31 +132,37 @@ The builtin commands available are:
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.Bl -tag -width Ds -compact -offset indent
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.It Ic autoboot Op Ar seconds
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Proceeds to bootstrap the system after a number of seconds, if not
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interrupted by the user. Displays a countdown prompt warning the
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user the system is about to be booted, unless interrupted by a key
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press. The kernel will be loaded first if necessary. Defaults to
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10 seconds.
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interrupted by the user.
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Displays a countdown prompt
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warning the user the system is about to be booted,
|
||||
unless interrupted by a key press.
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The kernel will be loaded first if necessary.
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Defaults to 10 seconds.
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.Pp
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.It Ic bcachestat
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Displays statistics about disk cache usage. For depuration only.
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Displays statistics about disk cache usage.
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For depuration only.
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.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
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if necessary. Any flags or arguments are passed to the kernel, but they
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if necessary.
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Any flags or arguments are passed to the kernel, but they
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must precede the kernel name, if a kernel name is provided.
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.Pp
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.It Ic echo Xo
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.Op Fl n
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.Op Aq message
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.Xc
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Displays a text on the screen. A new line will be printed unless
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Displays a text on the screen.
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A new line will be printed unless
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.Fl n
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is specified.
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.Pp
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.It Ic heap
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Displays memory usage statistics. For debugging purposes only.
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Displays memory usage statistics.
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For debugging purposes only.
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.Pp
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.It Ic help Op topic Op subtopic
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Shows help messages read from
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@ -156,9 +172,10 @@ The special topic
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will list the topics available.
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.Pp
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.It Ic include Ar file Op Ar
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Process script files. Each file is, at a turn, completely read into
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memory, and then have each of its lines passed to the command line
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interpreter. If any error is returned by the interpreter, the include
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Process script files.
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Each file is, at a turn, completely read into memory,
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and then have each of its lines passed to the command line interpreter.
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If any error is returned by the interpreter, the include
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commands aborts immediately, without reading any other files, and
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returns an error itself (see
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.Sx ERRORS ) .
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@ -170,10 +187,10 @@ returns an error itself (see
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Loads a kernel, kernel loadable module (kld), or a file of opaque
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contents tagged as being of the type
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.Ar type .
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Kernel and modules can be either in a.out or elf format. Any arguments
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passed after the name of the file to be loaded will be passed as
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arguments to that file. Notice, though, that, at the present, this does
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not work for the kernel.
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Kernel and modules can be either in a.out or elf format.
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Any arguments passed after the name of the file to be loaded
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will be passed as arguments to that file.
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Notice, though, that, at the present, this does not work for the kernel.
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.Pp
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.It Ic ls Xo
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.Op Fl l
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@ -183,17 +200,20 @@ Displays a listing of files in the directory
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.Ar path ,
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or the root directory if
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.Ar path
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is not specified. If
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is not specified.
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If
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.Fl l
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is specified, file sizes will be shown too.
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.Pp
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.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
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Lists all of the devices from which it may be possible to load modules.
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If
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.Fl v
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||||
is specified, more details are printed.
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.Pp
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.It Ic lsmod Op Fl v
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Displays loaded modules. If
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Displays loaded modules.
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If
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.Fl v
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is specified, more details are shown.
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.Pp
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@ -203,7 +223,8 @@ Display the files specified, with a pause at each
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displayed.
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.Pp
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.It Ic pnpscan Op Fl v
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Scans for Plug-and-Play devices. This is not functional at the present.
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Scans for Plug-and-Play devices.
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This is not functional at the present.
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.Pp
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.It Ic read Xo
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.Op Fl t Ar seconds
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@ -212,10 +233,11 @@ Scans for Plug-and-Play devices. This is not functional at the present.
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.Xc
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Reads a line of input from the terminal, storing it in
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.Va variable
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if specified. A timeout can be specified with
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if specified.
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A timeout can be specified with
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.Fl t ,
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though it will be canceled at the first key pressed. A prompt may
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also be displayed through the
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though it will be canceled at the first key pressed.
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A prompt may also be displayed through the
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.Fl p
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flag.
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.Pp
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@ -250,11 +272,12 @@ The
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.Nm
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has actually two different kinds of
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.Sq environment
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variables. There are ANS Forth's
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variables.
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There are ANS Forth's
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.Em environmental queries ,
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and a separate space of environment variables used by builtins, which
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are not directly available to Forth words. It is the later ones that
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this session covers.
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are not directly available to Forth words.
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It is the later ones that this session covers.
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.Pp
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Environment variables can be set and unset through the use of the
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.Ic set
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@ -263,7 +286,8 @@ and
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builtins, and have their value interactively examined through the
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use of the
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.Ic show
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builtin. Their values can also be accessed as described in
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builtin.
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Their values can also be accessed as described in
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.Sx BUILTIN PARSER .
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.Pp
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Notice that this environment variables are not inherited by any shell
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@ -273,13 +297,16 @@ A few variables are set automatically by
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.Nm loader .
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Others can affect either
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.Nm
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or kernel's behavior at boot. While some of these may require a value,
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others define behavior just by being set. These are described below.
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or kernel's behavior at boot.
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While some of these may require a value,
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others define behavior just by being set.
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These are described below.
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.Bl -tag -width bootfile -offset indent
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.It Va autoboot_delay
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Number of seconds
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.Ic autoboot
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will wait before booting. If this variable is not defined,
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will wait before booting.
|
||||
If this variable is not defined,
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.Ic autoboot
|
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will default to 10 seconds.
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.Pp
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@ -310,16 +337,18 @@ be run when the kernel is booted.
|
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Setting this variable causes extra debugging information to be printed
|
||||
by the kernel during the boot phase.
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||||
.It Va bootfile
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List of semicolon-separated search path for bootable kernels. The default
|
||||
is
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List of semicolon-separated search path for bootable kernels.
|
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The default is
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.Li Dq kernel;kernel.old .
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.It Va console
|
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Defines the current console.
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||||
.It Va currdev
|
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Selects the default device. Syntax for devices is odd.
|
||||
Selects the default device.
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Syntax for devices is odd.
|
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.It Va init_path
|
||||
Sets the list of binaries which the kernel will try to run as initial
|
||||
process. The default is
|
||||
process.
|
||||
The default is
|
||||
.Li Dq /sbin/init:/sbin/oinit:/sbin/init.bak:/stand/sysinstall .
|
||||
.It Va interpret
|
||||
Has the value
|
||||
@ -329,17 +358,19 @@ if the Forth's current state is interpreting.
|
||||
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 in for modules
|
||||
named in a load command or implicitly required by a dependancy. The
|
||||
default value for this variable is
|
||||
named in a load command or implicitly required by a dependancy.
|
||||
The default value for this variable is
|
||||
.Li Dq /;/boot;/modules .
|
||||
.It Va num_ide_disks
|
||||
Sets the number of IDE disks as a work around for some problems in
|
||||
finding the root disk at boot. This has been deprecated in favour of
|
||||
finding the root disk at boot.
|
||||
This has been deprecated in favour of
|
||||
.Va root_disk_unit .
|
||||
.It Va prompt
|
||||
Value of
|
||||
.Nm Ns No 's
|
||||
prompt. Defaults to
|
||||
prompt.
|
||||
Defaults to
|
||||
.Li Dq "${currdev}>" .
|
||||
.It Va root_disk_unit
|
||||
If the code which detects the disk unit number for the root disk is
|
||||
@ -350,7 +381,8 @@ be forced by setting this variable.
|
||||
By default the value of
|
||||
.Va currdev
|
||||
is used to set the root filesystem
|
||||
when the kernel is booted. This can be overridden by setting
|
||||
when the kernel is booted.
|
||||
This can be overridden by setting
|
||||
.Va rootdev
|
||||
explicitly.
|
||||
.El
|
||||
@ -359,25 +391,29 @@ Other variables are used to override kernel tunnable parameters.
|
||||
The following tunables are available:
|
||||
.Bl -tag -width Va -offset indent
|
||||
.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
|
||||
Set the number of mbuf clusters to be allocated.
|
||||
The value cannot be set below the default
|
||||
determined when the kernel was compiled.
|
||||
Modifies
|
||||
.Va NMBCLUSTERS .
|
||||
.It Va kern.vm.kmem.size
|
||||
Sets the size of kernel memory (bytes). This overrides
|
||||
completely the value determined when the kernel was
|
||||
compiled. Modifies
|
||||
Sets the size of kernel memory (bytes).
|
||||
This overrides completely the value
|
||||
determined when the kernel was compiled.
|
||||
Modifies
|
||||
.Va VM_KMEM_SIZE .
|
||||
.It Va machdep.pccard.pcic_irq
|
||||
Overrides the IRQ normally assigned to a PCCARD controller.
|
||||
Typically the first available interrupt will be allocated,
|
||||
which may conflict with other hardware. If this value is
|
||||
set to 0, an interrupt will not be assigned and the
|
||||
controller will operate in polled mode only.
|
||||
which may conflict with other hardware.
|
||||
If this value is set to 0,
|
||||
an interrupt will not be assigned
|
||||
and the controller will operate in polled mode only.
|
||||
.It Va net.inet.tcp.tcbhashsize
|
||||
Overrides the compile-time set value of
|
||||
.Va TCBHASHSIZE
|
||||
or the preset default of 512. Must be a power of 2.
|
||||
or the preset default of 512.
|
||||
Must be a power of 2.
|
||||
.El
|
||||
.Ss BUILTIN PARSER
|
||||
When a builtin command is executed, the rest of the line is taken
|
||||
@ -400,7 +436,8 @@ All backslash characters are preprocessed.
|
||||
.Tn ASCII
|
||||
11.
|
||||
.It
|
||||
\ez is just skipped. Useful for things like
|
||||
\ez is just skipped.
|
||||
Useful for things like
|
||||
.Dq \e0xf\ez\e0xf .
|
||||
.It
|
||||
\e0xN and \e0xNN are replaced by the hex N or NN.
|
||||
@ -434,8 +471,9 @@ Spaces can also be escaped through the use of \e\e .
|
||||
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,
|
||||
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
|
||||
@ -444,15 +482,16 @@ following parameters on the stack:
|
||||
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.
|
||||
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
|
||||
While this behavior has benefits, it has its trade-offs.
|
||||
If the execution token of a builtin is acquired (through
|
||||
.Ic No '
|
||||
or
|
||||
.Ic No ['] ) ,
|
||||
@ -469,7 +508,8 @@ or
|
||||
is processed
|
||||
.Ef
|
||||
\&! This is particular annoying for programs that want or need to
|
||||
treat exceptions. In this case, it is recommended the use of a proxy.
|
||||
treat exceptions.
|
||||
In this case, it is recommended the use of a proxy.
|
||||
For example:
|
||||
.Dl : (boot) boot ;
|
||||
.Sh FICL
|
||||
@ -484,7 +524,8 @@ each line read interactively is then fed to
|
||||
.Tn FICL ,
|
||||
which may call
|
||||
.Nm
|
||||
back to execute the builtin words. The builtin
|
||||
back to execute the builtin words.
|
||||
The builtin
|
||||
.Ic include
|
||||
will also feed
|
||||
.Tn FICL ,
|
||||
@ -492,17 +533,21 @@ one line at a time.
|
||||
.Pp
|
||||
The words available to
|
||||
.Tn FICL
|
||||
can be classified in four groups. The
|
||||
can be classified in four groups.
|
||||
The
|
||||
.Tn ANS
|
||||
Forth standard words, extra
|
||||
.Tn FICL
|
||||
words, extra
|
||||
.Os
|
||||
words, and the builtin commands. The later were already described. The
|
||||
words, and the builtin commands.
|
||||
The later 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
|
||||
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 -offset indent
|
||||
@ -550,7 +595,8 @@ Reads a single character from a file.
|
||||
Process file
|
||||
.Em fd .
|
||||
.It Ic fopen Pq Ar addr len -- fd
|
||||
Open a file. Returns a file descriptor, or -1 in case of failure.
|
||||
Open a file.
|
||||
Returns a file descriptor, or -1 in case of failure.
|
||||
.It Xo
|
||||
.Ic fread
|
||||
.Pq Ar fd addr len -- len'
|
||||
@ -585,7 +631,8 @@ 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
|
||||
Activates or deactivates tracing.
|
||||
Does not work with
|
||||
.Ic catch .
|
||||
.El
|
||||
.Ss FREEBSD DEFINED ENVIRONMENTAL QUERIES
|
||||
@ -615,7 +662,8 @@ Additional
|
||||
initialization.
|
||||
.It Pa /boot/boot.conf
|
||||
.Nm
|
||||
bootstrapping script. Deprecated.
|
||||
bootstrapping script.
|
||||
Deprecated.
|
||||
.It Pa /boot/loader.rc
|
||||
.Nm
|
||||
bootstrapping script.
|
||||
@ -629,8 +677,8 @@ Boot in single user mode:
|
||||
.Pp
|
||||
.Dl boot -s
|
||||
.Pp
|
||||
Loads kernel's user configuration file. Notice that a kernel must be
|
||||
loaded before any other
|
||||
Loads kernel's user configuration file.
|
||||
Notice that a kernel must be loaded before any other
|
||||
.Ic load
|
||||
command is attempted.
|
||||
.Pp
|
||||
@ -648,9 +696,9 @@ load -t splash_image_data /boot/chuckrulez.bmp
|
||||
autoboot 5
|
||||
.Ed
|
||||
.Pp
|
||||
Sets the disk unit of the root device to 2, and then boots. This would
|
||||
be needed in the case of a two IDE disks system, with the second IDE
|
||||
hardwired to wd2 instead of wd1.
|
||||
Sets the disk unit of the root device to 2, and then boots.
|
||||
This would be needed in the case of a two IDE disks system,
|
||||
with the second IDE hardwired to wd2 instead of wd1.
|
||||
.Pp
|
||||
.Bd -literal -offset indent -compact
|
||||
set root_disk_unit=2
|
||||
@ -750,6 +798,5 @@ 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.
|
||||
|
||||
words will read from the input buffer instead of the console.
|
||||
The latter will be fixed, but the former will not.
|
||||
|
||||
Loading…
Reference in New Issue
Block a user