mkksiso¶
- Authors:
Brian C. Lane <bcl@redhat.com>
mkksiso
is a tool for creating kickstart boot isos. In it's simplest form
you can add a kickstart to a boot.iso and the kickstart will be executed when
the iso is booted. If the original iso was created with EFI and Mac support the
kickstart boot.iso will include this support as well.
mkksiso
The host system architecture needs to match that of the iso.
mkksiso
will raise an error if it finds a .discinfo on the iso with a
mismatched arch.
As of version 38.4 mkksiso
needs to be run as root to create a fully
bootable iso. Booting on a UEFI system with the iso written to a flash drive
requires updating the config files in the embedded efiboot image in the iso. If
you do not need this functionality you can still run it as a user by passing
--skip-mkefiboot.
mkksiso cmdline arguments¶
Add a kickstart and files to an iso
usage: mkksiso [-h] [-a ADD_PATHS] [-c CMDLINE] [-r ARGS] [--debug] [--no-md5sum] [--ks KICKSTART]
[-u IMAGE] [-V VOLID] [--skip-mkefiboot]
[KICKSTART] input_iso output_iso
Positional Arguments¶
- KICKSTART
Optional kickstart to add to the ISO
- input_iso
ISO to modify
- output_iso
Full pathname of iso to be created
Named Arguments¶
- -a, --add
File or directory to add to ISO (may be used multiple times)
Default: []
- -c, --cmdline
Arguments to add to kernel cmdline
Default: ""
- -r, --rm-args
Space separated list of arguments to remove from the kernel cmdline
Default: ""
- --debug
print debugging info
Default: 20
- --no-md5sum
Do not run implantisomd5 on the ouput iso
Default: True
- --ks
Optional kickstart to add to the ISO
- -u, --updates
Optional updates image to add to the ISO
- -V, --volid
Set the ISO volume id, defaults to input's
- --skip-mkefiboot
Skip running mkefiboot
Default: False
Create a kickstart boot.iso or DVD¶
Create a kickstart like you normally would, kickstart documentation can be
found here, including the
url
and repo
commands. If you are creating a DVD and only need the
content on the DVD you can use the cdrom
command to install without a
network connection. Then run mkksiso
like this:
mkksiso --ks /PATH/TO/KICKSTART /PATH/TO/ISO /PATH/TO/NEW-ISO
This will create a new iso with the kickstart in the root directory, and the
kernel cmdline will have inst.ks=...
added to it so that it will be
executed when the iso is booted (be careful not to boot on a system you don't
want to wipe out! There will be no prompting).
By default the volume id of the iso is preserved. You can set a custom volid by
passing -V
and the string to set. The kernel cmdline will be changes, and
the iso will have th custom volume id.
eg.:
mkksiso -V "Test Only" --ks /PATH/TO/KICKSTART /PATH/TO/ISO /PATH/TO/NEW-ISO
Adding package repos to a boot.iso¶
You can add repo directories to the iso using --add /PATH/TO/REPO/
, make
sure it contains the repodata
directory by running createrepo_c
on it
first. In the kickstart you can refer to the directories (and files) on the iso
using file:///run/install/repo/DIRECTORY/
. You can then use these repos in
the kickstart like this:
repo --name=extra-repo --baseurl=file:///run/install/repo/extra-repo/
Run mkksiso
like so:
mkksiso --add /PATH/TO/REPO/ --ks /PATH/TO/KICKSTART /PATH/TO/ISO /PATH/TO/NEW-ISO
Create a liveimg boot.iso¶
You can use the kickstart liveimg command, to install a pre-generated disk image or tar to the system the iso is booting on.
Create a disk image or tar with osbuild-composer
or livemedia-creator
,
make sure the image includes tools expected by anaconda
, as well as the
kernel and bootloader support. In osbuild-composer
use the tar
image
type and make sure to include the kernel
, grub2
, and grub2-tools
packages. If you plan to install it to a UEFI machine make sure to include
grub2-efi
and efibootmgr
in the blueprint.
Add the root.tar.xz
file to the iso using --add /PATH/TO/ROOT.TAR.XZ
,
and in the kickstart reference it with the liveimg
command like this:
liveimg --url=file:///run/install/repo/root.tar.xz
It is also a good idea to use the --checksum
argument to liveimg
to be
sure the file hasn't been corrupted:
mkksiso --add /PATH/TO/root.tar.xz --ks /PATH/TO/KICKSTART /PATH/TO/ISO /PATH/TO/NEW-ISO
When this iso is booted it will execute the kickstart and install the liveimg contents to the system without any prompting.
Modifying kernel cmdline arguments¶
You can add arguments to the kernel cmdline in the ISO config files by using
--cmdline
, like this:
mkksiso --cmdline "console=ttyS0,115200n8" /PATH/TO/ISO /PATH/TO/NEW-ISO
Removing arguments¶
mkksiso version 37.3 and later support removing arguments from the cmdline. This can be done with or without adding a kickstart to the iso:
mkksiso --rm "quiet console" /PATH/TO/ISO /PATH/TO/NEW-ISO
will remove the quiet and console arguments from all the the kernel cmdlines on the ISO.
Changing existing arguments¶
With the combination of --rm
and --command
it is now possible to change
existing arguments. For example let's say the ISO has a console=tty3 set on the
cmdline. You want to change that to ttyS0 so you run this:
mkksiso --cmdline "console=ttyS0,115200n8" --rm "console" /PATH/TO/ISO /PATH/TO/NEW-ISO
which will first remove all instances of console in the config files, and then add the new console argument.
How it works¶
mkksiso
only depends on xorriso
and isomd5sum
. It takes advantage of
xorriso
's ability to extract files, replace files, and add files to the iso
without need to mount it.
mkksiso
extracts all of the config files it knows about, and then modifies
the boot configuration files to include the inst.ks
command. It adds any
extra command line arguments you specify, and then builds the new iso with the configuration
files replaced, and new files and directories added.
The last step is to update the iso checksums so that booting with test enabled
will pass. It uses implantisomd5
from the isomd5sum
project.