tags/grubby-8_40_20200707/grubby.8

.TH GRUBBY 8 "Tue Jan 18 2005"

.SH NAME

grubby \- command line tool used to configure bootloader menu entries across
multiple architectures

.SH SYNOPSIS

\fBgrubby\fR [\fIOPTIONS\fR]

.SH DESCRIPTION

.SS General Information

\fBgrubby\fR is a command line tool for updating and displaying information
about the configuration files for various architecture specific bootloaders.
It is primarily designed to be used from scripts which install new kernels
and need to find information about the current boot environment.

.SS Architecture Support

The \fBgrubby\fR executable has full support for the \fBgrub2\fR
bootloader on \fBx86_64\fR systems using legacy BIOS or modern
UEFI firmware and \fBppc64\fR and \fBppc64le\fR hardware using
OPAL or SLOF as firmware.

Legacy \fBs390\fR and the current \fBs390x\fR architectures
and their \fBzipl\fR bootloader are fully supported.

Support for \fByaboot\fR has been deprecated as all ppc architecture
hardware since the Power8 uses \fBgrub2\fR or petitboot
which both use the grub2 configuration file format.

Legacy bootloaders \fBLILO\fR, \fBSILO\fR, and \fBELILO\fR
are deprecated and no longer receiving active support in favor of
previously mentioned bootloaders.

.SS Default Behavior

The default bootloader target is primarily determined by the architecture
for which grubby has been built.  Each architecture has a preferred
bootloader, and each bootloader has its own configuration file.  If no
bootloader is selected on the command line, grubby will use these default
settings to search for an existing configuration.  If no bootloader
configuration file is found, grubby will use the default value for that
architecture.  These defaults are listed in the table below.

.TS
allbox;
lbw6 lbw10 lbw18
l l l.
 Arch	Bootloader	Configuration File
 x86_64 [BIOS]	grub2	/boot/grub2/grub.cfg
 x86_64 [UEFI]	grub2	/boot/efi/EFI/redhat/grub.cfg
 i386	grub2	/boot/grub2/grub.cfg
 ia64	elilo	/boot/efi/EFI/redhat/elilo.conf
 ppc [>=Power8]	grub2	/boot/grub2/grub.cfg
 ppc [<=Power7]	yaboot	/etc/yaboot.conf
 s390	zipl	/etc/zipl.conf
 s390x	zipl	/etc/zipl.conf
.TE


.SS Special Arguments

There are a number of ways to specify the kernel used for \fB-\-info\fR,
\fB-\-remove-kernel\fR, and \fB-\-update-kernel\fR. Specifying \fBDEFAULT\fR
or \fBALL\fR selects the default entry and all of the entries, respectively.
If a comma separated list of numbers is given, the boot entries indexed
by those numbers are selected. Finally, the title of a boot entry may
be specified by using \fBTITLE=\fItitle\fR as the argument; all entries
with that title are used.

.SH OPTIONS

.SS Basic Options

.TP
\fB-\-add-kernel\fR=\fIkernel-path\fR
Add a new boot entry for the kernel located at \fIkernel-path\fR. A title for
the boot entry must be set using \fB-\-title\fR. Most invocations should also
include \fB-\-initrd\fR with memtest86 as a notable exception.

The \fB-\-update-kernel\fR option may not be used in the same invocation.

.TP
\fB-\-remove-kernel\fR=\fIkernel-path\fR
Remove all boot entries which match \fIkernel-path\fR. This may be used
along with \fB-\-add-kernel\fR, in which case the new entry being added will
not be removed.

.TP
\fB-\-update-kernel\fR=\fIkernel-path\fR
Update the entries for kernels matching \fRkernel-path\fR. Currently
the only item that can be updated is the kernel argument list, which is
modified via the \fB-\-args\fR and \fB-\-remove-args\fR options.

.TP
\fB-\-args\fR=\fIkernel-args\fR
When a new kernel is added, this specifies the command line arguments
which should be passed to the kernel by default (note they are merged
with the arguments from the template if \fB-\-copy-default\fR is used).
When \fB-\-update-kernel\fR is used, this specifies new arguments to add
to the argument list. Multiple, space separated arguments may be used. If
an argument already exists the new value replaces the old values. The
\fBroot=\fR kernel argument gets special handling if the configuration
file has special handling for specifying the root filesystem (like
lilo.conf does).

.TP
\fB-\-remove-args\fR=\fIkernel-args\fR
The arguments specified by \fIkernel-args\fR are removed from the
kernels specified by \fB-\-update-kernel\fR. The \fBroot\fR argument
gets special handling for configuration files that support separate root
filesystem configuration.

.TP
\fB-\-copy-default\fR
\fBgrubby\fR will copy as much information (such as kernel arguments and
root device) as possible from the current default kernel. The kernel path
and initrd path will never be copied.

.TP
\fB-\-title\fR=\fIentry-title\fR
When a new kernel entry is added \fIentry-title\fR is used as the title
(\fBlilo\fR label) for the entry. If \fIentry-title\fR is longer then maximum
length allowed by the bootloader (15 for lilo, unlimited for grub and elilo)
the title is shortened to a (unique) entry.

.TP
\fB-\-initrd\fR=\fIinitrd-path\fR
Use \fIinitrd-path\fR as the path to an initial ram disk for a new kernel
being added.

.TP
\fB-\-efi\fR
Use appropriate bootloader commands for EFI on this architecture.

.TP
\fB-\-set-default\fR=\fIkernel-path\fR
The first entry which boots the specified kernel is made the default
boot entry. This may not be invoked with \fB-\-set-default-index\fR.

.TP
\fB-\-set-default-index\fR=\fIentry-index\fR
Makes the given entry number the default boot entry. This may not be invoked
with \fB-\-set-default\fR.  The given value represents the index in the
post-modification boot entry list.

.TP
\fB-\-make-default\fR
Make the new kernel entry being added the default entry.

.TP
\fB-\-set-index\fR=\fIentry-index\fR
Set the position at which to add a new entry created with \fB-\-add-kernel\fR.

.TP
\fB-\-debug\fR
Display extra debugging information for failures.

.TP
\fB-i\fR, \fB-\-extra-initrd\fR=\fIinitrd-path\fR
Use \fIinitrd-path\fR as the path for an auxiliary initrd image.

.SS Display Options

Passing the display option to grubby will cause it to print out the
requested information about the current bootloader configuration and
then immediately exit.  These options should not be used in any
script intended to update the bootloader configuration.

.TP
\fB-\-default-kernel\fR
Display the full path to the current default kernel and exit.

.TP
\fB-\-default-index\fR
Display the numeric index of the current default boot entry and exit.

.TP
\fB-\-default-title\fR
Display the title of the current default boot entry and exit.

.TP
\fB-\-info\fR=\fIkernel-path\fR
Display information on all boot entries which match \fIkernel-path\fR. If
\fIkernel-path\fR is \fBDEFAULT\fR, then information on the default kernel
is displayed. If \fIkernel-path\fR is \fBALL\fR, then information on all boot
entries are displayed.

.TP
\fB-\-bootloader-probe\fR
Attempt to probe for installed bootloaders.  If this option is specified,
\fBgrubby\fR tries to determine if \fBgrub\fR or \fBlilo\fR is currently
installed. When one of those bootloaders is found the name of that
bootloader is displayed on stdout.  Both could be installed (on different
devices), and grubby will print out the names of both bootloaders, one per
line. The probe for \fBgrub\fR requires a commented out boot directive
\fBgrub.conf\fR identical to the standard directive in the lilo
configuration file. If this is not present \fBgrubby\fR will assume grub is
not installed (note that \fBanaconda\fR places this directive in
\fBgrub.conf\fR files it creates).

\fIThis option is only available on x86 BIOS platforms.\fR

.TP
\fB-v\fR, \fB-\-version\fR
Display the version of \fBgrubby\fR being run and then exit immediately.

.SS Output Format Options

Sane default options for the current platform are compiled into grubby on
a per platform basis. These defaults determine the format and layout of
the generated bootloader configuration file. A different configuration file
format may be specified on the command line if the system uses a supported
alternative bootloader.

.TP
\fB-\-elilo\fR
Use an \fBelilo\fR style configuration file. This is the default on ia64
platforms. This format is deprecated.

.TP
\fB-\-extlinux\fR
Use an \fBextlinux\fR style configuration file. This format is deprecated.

.TP
\fB-\-grub\fR
Use a \fBgrub\fR style configuration file. This is the default on the i386
architecture.

.TP
\fB-\-grub2\fR
Use a \fBgrub2\fR style configuration file. This is the default on
\fBx86_64\fR architecture as well as the \fBppc64\fR and \fBppc64le\fR
architectures running on Power8 or later hardware.

.TP
\fB-\-lilo\fR
Use a \fBlilo\fR style configuration file.

.TP
\fB-\-silo\fR
Use a \fBsilo\fR style configuration file. This is the default on SPARC
systems. This format is legacy, deprecated, and unsupported.

.TP
\fB-\-yaboot\fR
Use a \fByaboot\fR style configuration file. This is the default for
the \fBppc\fR architecture on on Power7 and earlier hardware.

.TP
\fB-\-zipl\fR
Use a \fBzipl\fR style configuration file. This is the default on the
legacy s390 and current s390x architectures.

.SS Override Options

.TP
\fB-\-bad-image-okay\fR
When \fBgrubby\fR is looking for a entry to use for something (such
as a template or a default boot entry) it uses sanity checks, such as
ensuring that the kernel exists in the filesystem, to make sure
entries that obviously won't work aren't selected. This option overrides
that behavior, and is designed primarily for testing.

.TP
\fB-\-boot-filesystem\fR=\fIbootfs\fR
The \fBgrub\fR boot loader expects file paths listed in its configuration
path to be relative to the top of the filesystem they are on, rather then
relative to the current root filesystem. By default \fBgrubby\fR searches
the list of currently mounted filesystems to determine this. If this option
is given \fBgrubby\fR acts as if the specified filesystem was the filesystem
containing the kernel (this option is designed primarily for testing).

.TP
\fB-\-env\fR=\fIpath\fR
Path for the file where grub environment data is stored.

.TP
\fB-c\fR, \fB-\-config-file\fR=\fIpath\fR
Use \fIpath\fR as the configuration file rather then the default.

.TP
\fB-o\fR, \fB-\-output-file\fR=\fIfile_path\fR
The destination path for the updated configuration file. Use "-" to
send it to stdout.

.TP
\fB-\-devtree\fR=\fIfile_path\fR
Use \fIpath\fR for device tree path in place of the path of any devicetree
directive found in the template stanza.

.TP
\fB-\-devtreedir\fR=\fIfile_path\fR
Use the specified \fIfile path\fR to load the devicetree definition. This is
for platforms where a flat file is used instead of firmware to instruct the
kernel how to communicate with devices.

.SS Multiboot Options

The Multiboot Specification provides a generic interface for boot
loaders and operating systems.  It is supported by the GRUB bootloader.

.TP
\fB-\-add-multiboot\fR=\fImultiboot-path\fR
Add a new boot entry for the multiboot kernel located at
\fImultiboot-path\fR.  Note that this is generally accompanied with a
\fB--add-kernel\fR option.

.TP
\fB-\-remove-multiboot\fR=\fImultiboot-path\fR
Removes all boot entries which match \fImultiboot-path\fR.

.TP
\fB-\-mbargs\fR=\fImultiboot-args\fR
When a new multiboot kernel is added, this specifies the command line
arguments which should be passed to that kernel by default
When \fB-\-update-kernel\fR is used, this specifies new arguments to add
to the argument list. Multiple, space separated arguments may be used. If
an argument already exists the new value replaces the old values.

.TP
\fB-\-remove-mbargs\fR=\fImultiboot-args\fR
The arguments specified by \fImultiboot-args\fR are removed from the
kernels specified by \fB-\-update-kernel\fR.

.SH "BUGS"

The command line syntax is more than a little baroque. This probably
won't be fixed as \fBgrubby\fR is only intended to be called from shell
scripts which can get it right.

.SH EXAMPLE

The following examples assume the following:

.TS
allbox;
rbw15 l.
cfg_file	Full path to bootloader config file
new_kernel	Full path to kernel image to be installed
old_kernel	Full path to old kernel image to be removed
current_kernel	Full path to a currently installed kernel
entry_title	Title that appears on bootloader menu
new_initrd	Full path to initrd for a new kernel
kernel_args	Set of arguments for the kernel
menu_index	Index number of a menu entry
.TE

The examples below quote strings that may have spaces or other whitespace in
them. It is also perfectly valid to backslash escape these strings if that
is more convenient.

.PP
Add a new kernel entry and copy all options from the current default kernel.
This is the behavior that most users will want.
.IP
\fBgrubby\fR --add-kernel=\fInew_kernel\fR --title="\fIentry_title\fR" --initrd="\fInew_initrd\fR" --copy-default
.PP
Add a new kernel entry with custom arguments
.IP
\fBgrubby\fR --add-kernel=\fInew_kernel\fR --title="\fIentry_title\fR" --initrd="\fInew_initrd\fR" --args=\fIkernel_args\fR
.PP
Remove \fBall menu entries\fR for a specified kernel.
.IP
\fBgrubby\fR --remove-kernel=\fIold_kernel\fR
.PP
Target a single menu entry to remove without targetting other entries with
the same kernel.
.IP
\fBgrubby\fR --info=\fIold_kernel\fR

\fBgrubby\fR --remove-kernel=\fImenu_index\fR
.PP
Update the arguments for all entries of a specific kernel. New arguments get
added while existing arguments get updated values.
.IP
\fBgrubby\fR --update-kernel=\fIcurrent_kernel\fR --args="\fIkernel_args\fR"
.PP
Remove the arguments for a single entry of a specific kernel.
.IP
\fBgrubby\fR --info=\fIcurrent_kernel\fR

\fBgrubby\fR --remove-args=\fImenu_index\fR --args="\fIkernel_args\fR"

.SH "SEE ALSO"

.BR grub (8),
.BR lilo (8),
.BR yaboot (8),
.BR zipl (8),
.BR dracut (8),
.BR mkinitrd (8)

.SH AUTHORS

.nf
Erik Troan
Jeremy Katz
Peter Jones
Robert Marshall
.fi
1	.TH GRUBBY 8 "Tue Jan 18 2005"
2
3	.SH NAME
4
5	grubby \- command line tool used to configure bootloader menu entries across
6	multiple architectures
7
8	.SH SYNOPSIS
9
10	\fBgrubby\fR [\fIOPTIONS\fR]
11
12	.SH DESCRIPTION
13
14	.SS General Information
15
16	\fBgrubby\fR is a command line tool for updating and displaying information
17	about the configuration files for various architecture specific bootloaders.
18	It is primarily designed to be used from scripts which install new kernels
19	and need to find information about the current boot environment.
20
21	.SS Architecture Support
22
23	The \fBgrubby\fR executable has full support for the \fBgrub2\fR
24	bootloader on \fBx86_64\fR systems using legacy BIOS or modern
25	UEFI firmware and \fBppc64\fR and \fBppc64le\fR hardware using
26	OPAL or SLOF as firmware.
27
28	Legacy \fBs390\fR and the current \fBs390x\fR architectures
29	and their \fBzipl\fR bootloader are fully supported.
30
31	Support for \fByaboot\fR has been deprecated as all ppc architecture
32	hardware since the Power8 uses \fBgrub2\fR or petitboot
33	which both use the grub2 configuration file format.
34
35	Legacy bootloaders \fBLILO\fR, \fBSILO\fR, and \fBELILO\fR
36	are deprecated and no longer receiving active support in favor of
37	previously mentioned bootloaders.
38
39	.SS Default Behavior
40
41	The default bootloader target is primarily determined by the architecture
42	for which grubby has been built. Each architecture has a preferred
43	bootloader, and each bootloader has its own configuration file. If no
44	bootloader is selected on the command line, grubby will use these default
45	settings to search for an existing configuration. If no bootloader
46	configuration file is found, grubby will use the default value for that
47	architecture. These defaults are listed in the table below.
48
49	.TS
50	allbox;
51	lbw6 lbw10 lbw18
52	l l l.
53	Arch Bootloader Configuration File
54	x86_64 [BIOS] grub2 /boot/grub2/grub.cfg
55	x86_64 [UEFI] grub2 /boot/efi/EFI/redhat/grub.cfg
56	i386 grub2 /boot/grub2/grub.cfg
57	ia64 elilo /boot/efi/EFI/redhat/elilo.conf
58	ppc [>=Power8] grub2 /boot/grub2/grub.cfg
59	ppc [<=Power7] yaboot /etc/yaboot.conf
60	s390 zipl /etc/zipl.conf
61	s390x zipl /etc/zipl.conf
62	.TE
63
64
65	.SS Special Arguments
66
67	There are a number of ways to specify the kernel used for \fB-\-info\fR,
68	\fB-\-remove-kernel\fR, and \fB-\-update-kernel\fR. Specifying \fBDEFAULT\fR
69	or \fBALL\fR selects the default entry and all of the entries, respectively.
70	If a comma separated list of numbers is given, the boot entries indexed
71	by those numbers are selected. Finally, the title of a boot entry may
72	be specified by using \fBTITLE=\fItitle\fR as the argument; all entries
73	with that title are used.
74
75	.SH OPTIONS
76
77	.SS Basic Options
78
79	.TP
80	\fB-\-add-kernel\fR=\fIkernel-path\fR
81	Add a new boot entry for the kernel located at \fIkernel-path\fR. A title for
82	the boot entry must be set using \fB-\-title\fR. Most invocations should also
83	include \fB-\-initrd\fR with memtest86 as a notable exception.
84
85	The \fB-\-update-kernel\fR option may not be used in the same invocation.
86
87	.TP
88	\fB-\-remove-kernel\fR=\fIkernel-path\fR
89	Remove all boot entries which match \fIkernel-path\fR. This may be used
90	along with \fB-\-add-kernel\fR, in which case the new entry being added will
91	not be removed.
92
93	.TP
94	\fB-\-update-kernel\fR=\fIkernel-path\fR
95	Update the entries for kernels matching \fRkernel-path\fR. Currently
96	the only item that can be updated is the kernel argument list, which is
97	modified via the \fB-\-args\fR and \fB-\-remove-args\fR options.
98
99	.TP
100	\fB-\-args\fR=\fIkernel-args\fR
101	When a new kernel is added, this specifies the command line arguments
102	which should be passed to the kernel by default (note they are merged
103	with the arguments from the template if \fB-\-copy-default\fR is used).
104	When \fB-\-update-kernel\fR is used, this specifies new arguments to add
105	to the argument list. Multiple, space separated arguments may be used. If
106	an argument already exists the new value replaces the old values. The
107	\fBroot=\fR kernel argument gets special handling if the configuration
108	file has special handling for specifying the root filesystem (like
109	lilo.conf does).
110
111	.TP
112	\fB-\-remove-args\fR=\fIkernel-args\fR
113	The arguments specified by \fIkernel-args\fR are removed from the
114	kernels specified by \fB-\-update-kernel\fR. The \fBroot\fR argument
115	gets special handling for configuration files that support separate root
116	filesystem configuration.
117
118	.TP
119	\fB-\-copy-default\fR
120	\fBgrubby\fR will copy as much information (such as kernel arguments and
121	root device) as possible from the current default kernel. The kernel path
122	and initrd path will never be copied.
123
124	.TP
125	\fB-\-title\fR=\fIentry-title\fR
126	When a new kernel entry is added \fIentry-title\fR is used as the title
127	(\fBlilo\fR label) for the entry. If \fIentry-title\fR is longer then maximum
128	length allowed by the bootloader (15 for lilo, unlimited for grub and elilo)
129	the title is shortened to a (unique) entry.
130
131	.TP
132	\fB-\-initrd\fR=\fIinitrd-path\fR
133	Use \fIinitrd-path\fR as the path to an initial ram disk for a new kernel
134	being added.
135
136	.TP
137	\fB-\-efi\fR
138	Use appropriate bootloader commands for EFI on this architecture.
139
140	.TP
141	\fB-\-set-default\fR=\fIkernel-path\fR
142	The first entry which boots the specified kernel is made the default
143	boot entry. This may not be invoked with \fB-\-set-default-index\fR.
144
145	.TP
146	\fB-\-set-default-index\fR=\fIentry-index\fR
147	Makes the given entry number the default boot entry. This may not be invoked
148	with \fB-\-set-default\fR. The given value represents the index in the
149	post-modification boot entry list.
150
151	.TP
152	\fB-\-make-default\fR
153	Make the new kernel entry being added the default entry.
154
155	.TP
156	\fB-\-set-index\fR=\fIentry-index\fR
157	Set the position at which to add a new entry created with \fB-\-add-kernel\fR.
158
159	.TP
160	\fB-\-debug\fR
161	Display extra debugging information for failures.
162
163	.TP
164	\fB-i\fR, \fB-\-extra-initrd\fR=\fIinitrd-path\fR
165	Use \fIinitrd-path\fR as the path for an auxiliary initrd image.
166
167	.SS Display Options
168
169	Passing the display option to grubby will cause it to print out the
170	requested information about the current bootloader configuration and
171	then immediately exit. These options should not be used in any
172	script intended to update the bootloader configuration.
173
174	.TP
175	\fB-\-default-kernel\fR
176	Display the full path to the current default kernel and exit.
177
178	.TP
179	\fB-\-default-index\fR
180	Display the numeric index of the current default boot entry and exit.
181
182	.TP
183	\fB-\-default-title\fR
184	Display the title of the current default boot entry and exit.
185
186	.TP
187	\fB-\-info\fR=\fIkernel-path\fR
188	Display information on all boot entries which match \fIkernel-path\fR. If
189	\fIkernel-path\fR is \fBDEFAULT\fR, then information on the default kernel
190	is displayed. If \fIkernel-path\fR is \fBALL\fR, then information on all boot
191	entries are displayed.
192
193	.TP
194	\fB-\-bootloader-probe\fR
195	Attempt to probe for installed bootloaders. If this option is specified,
196	\fBgrubby\fR tries to determine if \fBgrub\fR or \fBlilo\fR is currently
197	installed. When one of those bootloaders is found the name of that
198	bootloader is displayed on stdout. Both could be installed (on different
199	devices), and grubby will print out the names of both bootloaders, one per
200	line. The probe for \fBgrub\fR requires a commented out boot directive
201	\fBgrub.conf\fR identical to the standard directive in the lilo
202	configuration file. If this is not present \fBgrubby\fR will assume grub is
203	not installed (note that \fBanaconda\fR places this directive in
204	\fBgrub.conf\fR files it creates).
205
206	\fIThis option is only available on x86 BIOS platforms.\fR
207
208	.TP
209	\fB-v\fR, \fB-\-version\fR
210	Display the version of \fBgrubby\fR being run and then exit immediately.
211
212	.SS Output Format Options
213
214	Sane default options for the current platform are compiled into grubby on
215	a per platform basis. These defaults determine the format and layout of
216	the generated bootloader configuration file. A different configuration file
217	format may be specified on the command line if the system uses a supported
218	alternative bootloader.
219
220	.TP
221	\fB-\-elilo\fR
222	Use an \fBelilo\fR style configuration file. This is the default on ia64
223	platforms. This format is deprecated.
224
225	.TP
226	\fB-\-extlinux\fR
227	Use an \fBextlinux\fR style configuration file. This format is deprecated.
228
229	.TP
230	\fB-\-grub\fR
231	Use a \fBgrub\fR style configuration file. This is the default on the i386
232	architecture.
233
234	.TP
235	\fB-\-grub2\fR
236	Use a \fBgrub2\fR style configuration file. This is the default on
237	\fBx86_64\fR architecture as well as the \fBppc64\fR and \fBppc64le\fR
238	architectures running on Power8 or later hardware.
239
240	.TP
241	\fB-\-lilo\fR
242	Use a \fBlilo\fR style configuration file.
243
244	.TP
245	\fB-\-silo\fR
246	Use a \fBsilo\fR style configuration file. This is the default on SPARC
247	systems. This format is legacy, deprecated, and unsupported.
248
249	.TP
250	\fB-\-yaboot\fR
251	Use a \fByaboot\fR style configuration file. This is the default for
252	the \fBppc\fR architecture on on Power7 and earlier hardware.
253
254	.TP
255	\fB-\-zipl\fR
256	Use a \fBzipl\fR style configuration file. This is the default on the
257	legacy s390 and current s390x architectures.
258
259	.SS Override Options
260
261	.TP
262	\fB-\-bad-image-okay\fR
263	When \fBgrubby\fR is looking for a entry to use for something (such
264	as a template or a default boot entry) it uses sanity checks, such as
265	ensuring that the kernel exists in the filesystem, to make sure
266	entries that obviously won't work aren't selected. This option overrides
267	that behavior, and is designed primarily for testing.
268
269	.TP
270	\fB-\-boot-filesystem\fR=\fIbootfs\fR
271	The \fBgrub\fR boot loader expects file paths listed in its configuration
272	path to be relative to the top of the filesystem they are on, rather then
273	relative to the current root filesystem. By default \fBgrubby\fR searches
274	the list of currently mounted filesystems to determine this. If this option
275	is given \fBgrubby\fR acts as if the specified filesystem was the filesystem
276	containing the kernel (this option is designed primarily for testing).
277
278	.TP
279	\fB-\-env\fR=\fIpath\fR
280	Path for the file where grub environment data is stored.
281
282	.TP
283	\fB-c\fR, \fB-\-config-file\fR=\fIpath\fR
284	Use \fIpath\fR as the configuration file rather then the default.
285
286	.TP
287	\fB-o\fR, \fB-\-output-file\fR=\fIfile_path\fR
288	The destination path for the updated configuration file. Use "-" to
289	send it to stdout.
290
291	.TP
292	\fB-\-devtree\fR=\fIfile_path\fR
293	Use \fIpath\fR for device tree path in place of the path of any devicetree
294	directive found in the template stanza.
295
296	.TP
297	\fB-\-devtreedir\fR=\fIfile_path\fR
298	Use the specified \fIfile path\fR to load the devicetree definition. This is
299	for platforms where a flat file is used instead of firmware to instruct the
300	kernel how to communicate with devices.
301
302	.SS Multiboot Options
303
304	The Multiboot Specification provides a generic interface for boot
305	loaders and operating systems. It is supported by the GRUB bootloader.
306
307	.TP
308	\fB-\-add-multiboot\fR=\fImultiboot-path\fR
309	Add a new boot entry for the multiboot kernel located at
310	\fImultiboot-path\fR. Note that this is generally accompanied with a
311	\fB--add-kernel\fR option.
312
313	.TP
314	\fB-\-remove-multiboot\fR=\fImultiboot-path\fR
315	Removes all boot entries which match \fImultiboot-path\fR.
316
317	.TP
318	\fB-\-mbargs\fR=\fImultiboot-args\fR
319	When a new multiboot kernel is added, this specifies the command line
320	arguments which should be passed to that kernel by default
321	When \fB-\-update-kernel\fR is used, this specifies new arguments to add
322	to the argument list. Multiple, space separated arguments may be used. If
323	an argument already exists the new value replaces the old values.
324
325	.TP
326	\fB-\-remove-mbargs\fR=\fImultiboot-args\fR
327	The arguments specified by \fImultiboot-args\fR are removed from the
328	kernels specified by \fB-\-update-kernel\fR.
329
330	.SH "BUGS"
331
332	The command line syntax is more than a little baroque. This probably
333	won't be fixed as \fBgrubby\fR is only intended to be called from shell
334	scripts which can get it right.
335
336	.SH EXAMPLE
337
338	The following examples assume the following:
339
340	.TS
341	allbox;
342	rbw15 l.
343	cfg_file Full path to bootloader config file
344	new_kernel Full path to kernel image to be installed
345	old_kernel Full path to old kernel image to be removed
346	current_kernel Full path to a currently installed kernel
347	entry_title Title that appears on bootloader menu
348	new_initrd Full path to initrd for a new kernel
349	kernel_args Set of arguments for the kernel
350	menu_index Index number of a menu entry
351	.TE
352
353	The examples below quote strings that may have spaces or other whitespace in
354	them. It is also perfectly valid to backslash escape these strings if that
355	is more convenient.
356
357	.PP
358	Add a new kernel entry and copy all options from the current default kernel.
359	This is the behavior that most users will want.
360	.IP
361	\fBgrubby\fR --add-kernel=\fInew_kernel\fR --title="\fIentry_title\fR" --initrd="\fInew_initrd\fR" --copy-default
362	.PP
363	Add a new kernel entry with custom arguments
364	.IP
365	\fBgrubby\fR --add-kernel=\fInew_kernel\fR --title="\fIentry_title\fR" --initrd="\fInew_initrd\fR" --args=\fIkernel_args\fR
366	.PP
367	Remove \fBall menu entries\fR for a specified kernel.
368	.IP
369	\fBgrubby\fR --remove-kernel=\fIold_kernel\fR
370	.PP
371	Target a single menu entry to remove without targetting other entries with
372	the same kernel.
373	.IP
374	\fBgrubby\fR --info=\fIold_kernel\fR
375
376	\fBgrubby\fR --remove-kernel=\fImenu_index\fR
377	.PP
378	Update the arguments for all entries of a specific kernel. New arguments get
379	added while existing arguments get updated values.
380	.IP
381	\fBgrubby\fR --update-kernel=\fIcurrent_kernel\fR --args="\fIkernel_args\fR"
382	.PP
383	Remove the arguments for a single entry of a specific kernel.
384	.IP
385	\fBgrubby\fR --info=\fIcurrent_kernel\fR
386
387	\fBgrubby\fR --remove-args=\fImenu_index\fR --args="\fIkernel_args\fR"
388
389	.SH "SEE ALSO"
390
391	.BR grub (8),
392	.BR lilo (8),
393	.BR yaboot (8),
394	.BR zipl (8),
395	.BR dracut (8),
396	.BR mkinitrd (8)
397
398	.SH AUTHORS
399
400	.nf
401	Erik Troan
402	Jeremy Katz
403	Peter Jones
404	Robert Marshall
405	.fi