1GRUBBY(8) System Manager's Manual GRUBBY(8)
2
6 grubby - command line tool for configuring grub, lilo, elilo, yaboot
7 and zipl
8
11 grubby [--add-kernel=kernel-path] [--args=args]
12 [--bad-image-okay] [--boot-filesystem=bootfs]
13 [--bootloader-probe] [--config-file path] [--copy-default]
14 [--debug] [--default-kernel] [--default-index] [--default-title]
15 [--devtree=devicetree.dtb]
16 [--grub] [--lilo] [--yaboot] [--silo] [--zipl]
17 [--info=kernel-path] [--initrd=initrd-path]
18 [--make-default] [-o path] [--version]
19 [--remove-kernel=kernel-path] [--remove-args=args]
20 [--set-default=kernel-path] [--set-default-index=entry-index]
21 [--title=entry-title] [--add-multiboot=multiboot-path]
22 [--mbargs=args] [--remove-multiboot=multiboot-path]
23 [--remove-mbargs=args]
24
27 grubby is a command line tool for updating and displaying information
28 about the configuration files for the grub, lilo, elilo (ia64), yaboot
29 (powerpc) and zipl (s390) boot loaders. It is primarily designed to be
30 used from scripts which install new kernels and need to find informa‐
31 tion about the current boot environment.
32 On BIOS-based Intel x86 platforms, grub2 is the default bootloader and
34 the configuration file is in /boot/grub2/grub.cfg. On UEFI-based Intel
35 x86 platforms, grub2 is the default bootloader, and the configuration
36 file is in /boot/efi/EFI/redhat/grub.cfg. On Intel ia64 platforms,
37 elilo mode is used and the default location for the configuration file
38 is /boot/efi/EFI/redhat/elilo.conf. On PowerPC platforms, systems based
39 on Power8 now support grub2 as a bootloader and store using a default
40 config stored in /boot/grub2/grub.cfg. The earlier Power7 systems use
41 yaboot parsing and the configuration file should be in
42 /etc/yaboot.conf. On s390 platforms the zipl bootloader will read from
43 /etc/zipl.conf.
44 There are a number of ways to specify the kernel used for --info,
46 --remove-kernel, and --update-kernel. Specificying DEFAULT or ALL
47 selects the default entry and all of the entries, respectively. If a
48 comma separated list of numbers is given, the boot entries indexed by
49 those numbers are selected. Finally, the title of a boot entry may be
50 specified by using TITLE=title as the argument; all entries with that
51 title are used.
52
55 --add-kernel=kernel-path
56 Add a new boot entry for the kernel located at kernel-path.
57 --args=kernel-args
60 When a new kernel is added, this specifies the command line
61 arguments which should be passed to the kernel by default (note
62 they are merged with the arguments from the template if --copy-
63 default is used). When --update-kernel is used, this specifies
64 new arguments to add to the argument list. Multiple, space sepa‐
65 rated arguments may be used. If an argument already exists the
66 new value replaces the old values. The root= kernel argument
67 gets special handling if the configuration file has special han‐
68 dling for specifying the root filesystem (like lilo.conf does).
69 --bad-image-okay
72 When grubby is looking for a entry to use for something (such as
73 a template or a default boot entry) it uses sanity checks, such
74 as ensuring that the kernel exists in the filesystem, to make
75 sure entries that obviously won't work aren't selected. This
76 option overrides that behavior, and is designed primarily for
77 testing.
78 --boot-filesystem=bootfs
81 The grub boot loader expects file paths listed in it's configu‐
82 ration path to be relative to the top of the filesystem they are
83 on, rather then relative to the current root filesystem. By
84 default grubby searches the list of currently mounted filesys‐
85 tems to determine this. If this option is given grubby acts as
86 if the specified filesystem was the filesystem containing the
87 kernel (this option is designed primarily for testing).
88 --bootloader-probe
91 grubby tries to determine if grub or lilo is currently
92 installed. When one of those bootloaders is found the name of
93 that bootloader is displayed on stdout. Both could be installed
94 (on different devices), and grubby will print out the names of
95 both bootloaders, one per line. The probe for grub requires a
96 commented out boot directive grub.conf identical to the standard
97 directive in the lilo configuration file. If this is not present
98 grubby will assume grub is not installed (note that anaconda
99 places this directive in grub.conf files it creates). This
100 option is only available on ia32 platforms.
101 --config-file=path
105 Use path as the configuration file rather then the default.
106 --copy-default
109 grubby will copy as much information (such as kernel arguments
110 and root device) as possible from the current default kernel.
111 The kernel path and initrd path will never be copied.
112 --debug
115 Display extra debugging information for failures.
116 --default-kernel
119 Display the full path to the current default kernel and exit.
120 --default-index
123 Display the numeric index of the current default boot entry and
124 exit.
125 --default-title
128 Display the title of the current default boot entry and exit.
129 --devtree=path
132 Use path for device tree path in place of the path of any
133 devicetree directive found in the template stanza.
134 --elilo
137 Use an elilo style configuration file.
138 --grub Use a grub style configuration file instead of lilo style. This
141 is the default on ia32 platforms.
142 --info=kernel-path
145 Display information on all boot entries which match kernel-path.
146 I
147 --initrd=initrd-path
150 Use initrd-path as the path to an initial ram disk for a new
151 kernel being added.
152 --lilo Use a lilo style configuration file.
155 --make-default
158 Make the new kernel entry being added the default entry.
159 --remove-args=kernel-args
162 The arguments specified by kernel-args are removed from the ker‐
163 nels specified by --update-kernel. The root argument gets spe‐
164 cial handling for configuration files that support separate root
165 filesystem configuration.
166 --remove-kernel=kernel-path
169 Removes all boot entries which match kernel-path. This may be
170 used along with --add-kernel, in which case the new kernel being
171 added will never be removed.
172 --set-default=kernel-path
175 The first entry which boots the specified kernel is made the
176 default boot entry.
177 --set-default-index=entry-index
180 Makes the given entry number the default boot entry.
181 --title=entry-title
184 When a new kernel entry is added entry-title is used as the
185 title (lilo label) for the entry. If entry-title is longer then
186 maximum length allowed by the bootloader (15 for lilo, unlimited
187 for grub and elilo) the title is shortened to a (unique) entry.
188 --update-kernel=kernel-path
191 The entries for kernels matching kernel-path are updated. Cur‐
192 rently the only items that can be updated is the kernel argument
193 list, which is modified via the --args and --remove-args
194 options.
195 --version
198 Display the version of grubby being run and then exit immedi‐
199 ately.
200 --yaboot
203 Use an yaboot style configuration file.
204 --zipl Use an zipl style configuration file.
207
210 The Multiboot Specification provides a genreic interface for boot load‐
211 ers and operating systems. It is supported by the GRUB bootloader.
212 --add-multiboot=multiboot-path
215 Add a new boot entry for the multiboot kernel located at multi‐
216 boot-path. Note that this is generally accompanied with a
217 --add-kernel option.
218 --remove-multiboot=multiboot-path
221 Removes all boot entries which match multiboot-path.
222 --mbargs=multiboot-args
225 When a new multiboot kernel is added, this specifies the command
226 line arguments which should be passed to that kernel by default
227 When --update-kernel is used, this specifies new arguments to
228 add to the argument list. Multiple, space separated arguments
229 may be used. If an argument already exists the new value
230 replaces the old values.
231 --remove-mbargs=multiboot-args
234 The arguments specified by multiboot-args are removed from the
235 kernels specified by --update-kernel.
236
240 The command line syntax is more than a little baroque. This probably
241 won't be fixed as grubby is only intended to be called from shell
242 scripts which can get it right.
243
246 grub(8), lilo(8), yaboot(8), mkinitrd(8)
247
250 Erik Troan
251 Jeremy Katz
252 Peter Jones
253 Tue Jan 18 2005 GRUBBY(8)