As @samp{GRUB_CMDLINE_LINUX} and @samp{GRUB_CMDLINE_LINUX_DEFAULT}, but for
NetBSD.
+@item GRUB_CMDLINE_XEN
+@itemx GRUB_CMDLINE_XEN_DEFAULT
+As @samp{GRUB_CMDLINE_LINUX} and @samp{GRUB_CMDLINE_LINUX_DEFAULT}, but for
+Linux and Xen.
+
@item GRUB_DISABLE_LINUX_UUID
Normally, @command{grub-mkconfig} will generate menu entries that use
universally-unique identifiers (UUIDs) to identify the root filesystem to
Depending on your kernel, your distribution, your graphics card, and the
phase of the moon, note that using this option may cause GNU/Linux to suffer
from various display problems, particularly during the early part of the
-boot sequence. If you have problems, simply unset this option and GRUB will
-tell Linux to boot in normal text mode.
+boot sequence. If you have problems, set this option to @samp{text} and
+GRUB will tell Linux to boot in normal text mode.
@item GRUB_DISABLE_OS_PROBER
Normally, @command{grub-mkconfig} will try to use the external
@node Shell-like scripting
@section Writing full configuration files directly
+@c Some of this section is derived from the GNU Bash manual page, also
+@c copyrighted by the FSF.
+
+@file{grub.cfg} is written in GRUB's built-in scripting language, which has
+a syntax quite similar to that of GNU Bash and other Bourne shell
+derivatives.
+
+@heading Words
+
+A @dfn{word} is a sequence of characters considered as a single unit by
+GRUB. Words are separated by @dfn{metacharacters}, which are the following
+plus space, tab, and newline:
+
+@example
+@{ @} | & $ ; < >
+@end example
+
+Quoting may be used to include metacharacters in words; see below.
+
+@heading Reserved words
+
+Reserved words have a special meaning to GRUB. The following words are
+recognised as reserved when unquoted and either the first word of a simple
+command or the third word of a @code{for} command:
+
+@example
+! [[ ]] @{ @}
+case do done elif else esac fi for function
+if in menuentry select then time until while
+@end example
+
+Not all of these reserved words have a useful purpose yet; some are reserved
+for future expansion.
+
+@heading Quoting
+
+Quoting is used to remove the special meaning of certain characters or
+words. It can be used to treat metacharacters as part of a word, to prevent
+reserved words from being recognised as such, and to prevent variable
+expansion.
+
+There are three quoting mechanisms: the escape character, single quotes, and
+double quotes.
+
+A non-quoted backslash (\) is the @dfn{escape character}. It preserves the
+literal value of the next character that follows, with the exception of
+newline.
+
+Enclosing characters in single quotes preserves the literal value of each
+character within the quotes. A single quote may not occur between single
+quotes, even when preceded by a backslash.
+
+Enclosing characters in double quotes preserves the literal value of all
+characters within the quotes, with the exception of @samp{$} and @samp{\}.
+The @samp{$} character retains its special meaning within double quotes.
+The backslash retains its special meaning only when followed by one of the
+following characters: @samp{$}, @samp{"}, @samp{\}, or newline. A
+backslash-newline pair is treated as a line continuation (that is, it is
+removed from the input stream and effectively ignored). A double quote may
+be quoted within double quotes by preceding it with a backslash.
+
+@heading Variable expansion
+
+The @samp{$} character introduces variable expansion. The variable name to
+be expanded may be enclosed in braces, which are optional but serve to
+protect the variable to be expanded from characters immediately following it
+which could be interpreted as part of the name.
+
+Normal variable names begin with an alphabetic character, followed by zero
+or more alphanumeric characters.
+
+Positional variable names consist of one or more digits. These are reserved
+for future expansion.
+
+The special variable name @samp{?} expands to the exit status of the most
+recently executed command.
+
+@heading Comments
+
+A word beginning with @samp{#} causes that word and all remaining characters
+on that line to be ignored.
+
+@heading Simple commands
+
+A @dfn{simple command} is a sequence of words separated by spaces or tabs
+and terminated by a semicolon or a newline. The first word specifies the
+command to be executed. The remaining words are passed as arguments to the
+invoked command.
+
+The return value of a simple command is its exit status.
+
+@heading Compound commands
+
+A @dfn{compound command} is one of the following:
+
+@table @asis
+@item for @var{name} in @var{word} @dots{}; do @var{list}; done
+The list of words following @code{in} is expanded, generating a list of
+items. The variable @var{name} is set to each element of this list in turn,
+and @var{list} is executed each time. The return value is the exit status
+of the last command that executes. If the expansion of the items following
+@code{in} results in an empty list, no commands are executed, and the return
+status is 0.
+
+@item if @var{list}; then @var{list}; [elif @var{list}; then @var{list};] @dots{} [else @var{list};] fi
+The @code{if} @var{list} is executed. If its exit status is zero, the
+@code{then} @var{list} is executed. Otherwise, each @code{elif} @var{list}
+is executed in turn, and if its exit status is zero, the corresponding
+@code{then} @var{list} is executed and the command completes. Otherwise,
+the @code{else} @var{list} is executed, if present. The exit status is the
+exit status of the last command executed, or zero if no condition tested
+true.
+
+@item while @var{cond}; do @var{list}; done
+@itemx until @var{cond}; do @var{list}; done
+The @code{while} command continuously executes the @code{do} @var{list} as
+long as the last command in @var{cond} returns an exit status of zero. The
+@code{until} command is identical to the @code{while} command, except that
+the test is negated; the @code{do} @var{list} is executed as long as the
+last command in @var{cond} returns a non-zero exit status. The exit status
+of the @code{while} and @code{until} commands is the exit status of the last
+@code{do} @var{list} command executed, or zero if none was executed.
+
+@item function @var{name} @{ @var{command}; @dots{} @}
+This defines a function named @var{name}. The @dfn{body} of the function is
+the list of commands within braces, each of which must be terminated with a
+semicolon or a newline. This list of commands will be executed whenever
+@var{name} is specified as the name of a simple command. Function
+definitions do not affect the exit status in @code{$?}. When executed, the
+exit status of a function is the exit status of the last command executed in
+the body.
+
+@item menuentry @var{title} [@option{--class=class} @dots{}] [@option{--users=users}] [@option{--hotkey=key}] @{ @var{command}; @dots{} @}
+@xref{menuentry}.
+@end table
+
@node Embedded configuration
@section Embedding a configuration file into GRUB
@example
@group
grub> @kbd{serial --unit=0 --speed=9600}
-grub> @kbd{terminal_input serial}
-grub> @kbd{terminal_output serial}
+grub> @kbd{terminal_input serial; terminal_output serial}
@end group
@end example
for more details.
The commands @command{terminal_input} (@pxref{terminal_input}) and
-@command{terminal_output} (@pxref{terminal_output} choose which type of
+@command{terminal_output} (@pxref{terminal_output}) choose which type of
terminal you want to use. In the case above, the terminal will be a
serial terminal, but you can also pass @code{console} to the command,
as @samp{terminal serial console}. In this case, a terminal in which
-you press any key will be selected as a GRUB terminal.
+you press any key will be selected as a GRUB terminal. In the example above,
+note that you need to put both commands on the same command line, as you
+will lose the ability to type commands on the console after the first
+command.
However, note that GRUB assumes that your terminal emulator is
compatible with VT100 by default. This is true for most terminal
@node menuentry
@subsection menuentry
-@deffn Command title name @dots{}
-Start a new boot entry, and set its name to the contents of the rest of
-the line, starting with the first non-space character.
+@deffn Command menuentry @var{title} @
+ [@option{--class=class} @dots{}] [@option{--users=users}] @
+ [@option{--hotkey=key}] @
+ @{ @var{command}; @dots{} @}
+This defines a GRUB menu entry named @var{title}. When this entry is
+selected from the menu, GRUB will set the @var{chosen} environment variable
+to @var{title}, execute the list of commands given within braces, and if the
+last command in the list returned successfully and a kernel was loaded it
+will execute the @command{boot} command.
+
+The @option{--class} option may be used any number of times to group menu
+entries into classes. Menu themes may display different classes using
+different styles.
+
+The @option{--users} option grants specific users access to specific menu
+entries. @xref{Security}.
+
+The @option{--hotkey} option associates a hotkey with a menu entry.
+@var{key} may be a single letter, or one of the aliases @samp{backspace},
+@samp{tab}, or @samp{delete}.
@end deffn
@option{-v} (@option{--visual-utf8}) options control how non-ASCII text is
displayed. @option{-a} specifies an ASCII-only terminal; @option{-u}
specifies logically-ordered UTF-8; and @option{-v} specifies
-visually-ordered UTF-8.
+"visually-ordered UTF-8" (in other words, arranged such that a terminal
+emulator without bidirectional text support will display right-to-left text
+in the proper order; this is not really proper UTF-8, but a workaround).
If no option or terminal type is specified, the current terminal type is
printed.
projects / thirdparty / grub.git / commitdiff
