Archiso

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Archiso is a small set of bash scripts capable of building fully functional Arch Linux live CD/DVD/USB images. It is the same tool used to generate the official images, but since it is a very generic tool, it can be used to generate anything from rescue systems, install disks, to special interest live CD/DVD/USB systems, and who knows what else. Simply put, if it involves Arch on a shiny coaster, it can do it. The heart and soul of Archiso is mkarchiso. All of its options are documented in its usage output, so its direct usage will not be covered here. Instead, this wiki article will act as a guide for rolling your own live media in no time!

If you require a technical run-down of requirements and build steps only, have a look at the official project documentation too.

Setup

Note: It is recommended to act as root in all the following steps. If not, it is very likely to have problems with false permissions later.

Before you begin, install the archiso or archiso-gitAUR package.

Archiso comes with two "profiles": releng and baseline.

  • If you wish to create a fully customized live version of Arch Linux, pre-installed with all your favorite programs and configurations, use releng.
  • If you just want to create the most basic live medium, with no pre-installed packages and a minimalistic configuration, use baseline.

Now, copy the profile of your choice to a directory (archlive in the example below) where you can make adjustments and build it. Execute the following, replacing profile with either releng or baseline.

# cp -r /usr/share/archiso/configs/profile/ archlive
  • If you are using the releng profile to make a fully customized image, then you can proceed onto #Configure the live medium.
  • If you are using the baseline profile to create a bare image, then you will not be needing to do any customization and can proceed onto #Build the ISO.

Configure the live medium

This section details configuring the image you will be creating, allowing you to define the packages and configurations you want your live image to contain.

Inside the archlive directory created in #Setup there are a number of files and directories; we are only concerned with a few of these, mainly:

  • packages.x86_64 - this is where you list, line by line, the packages you want to have installed, and
  • the airootfs directory - this directory acts as an overlay and it is where you make all the customizations.

Generally, every administrative task that you would normally do after a fresh install except for package installation can be scripted into archlive/airootfs/root/customize_airootfs.sh. It has to be written from the perspective of the new environment, so / in the script means the root of the live-iso which is to be created.

Installing packages

Edit the lists of packages in packages.x86_64 to indicate which packages are to be installed on the live medium.

Note: If you want to use a window manager in the Live CD then you must add the necessary and correct video drivers, or the WM may freeze on loading.

Custom local repository

Merge-arrows-2.pngThis article or section is a candidate for merging with Pacman tips#Custom local repository.Merge-arrows-2.png

Notes: Move the general information (e.g. repo tree) into the main article. (Discuss in Talk:Archiso#)

For the purpose of preparing custom packages or packages from AUR/ABS, you could also create a custom local repository. If you are looking to support multiple architectures then precautions should be taken to prevent errors from occurring. Each architecture should have its own directory tree:

$ tree ~/customrepo/ | sed "s/$(uname -m)/<arch>/g"
/home/archie/customrepo/
└── <arch>
    ├── customrepo.db -> customrepo.db.tar.xz
    ├── customrepo.db.tar.xz
    ├── customrepo.files -> customrepo.files.tar.xz
    ├── customrepo.files.tar.xz
    └── personal-website-git-b99cce0-1-<arch>.pkg.tar.xz

1 directory, 5 files

You can then add your repository by putting the following into ~/archlive/pacman.conf, above the other repository entries (for top priority):

~/archlive/pacman.conf
...
# custom repository
[customrepo]
SigLevel = Optional TrustAll
Server = file:///home/user/customrepo/$arch
...

The repo-add executable checks if the package is appropriate. If this is not the case you will be running into error messages similar to this:

==> ERROR: '/home/archie/customrepo/<arch>/foo-<arch>.pkg.tar.xz' does not have a valid database archive extension.

Preventing installation of packages belonging to base group

By default, /usr/bin/mkarchiso, a script which is used by ~/archlive/build.sh, calls one of the arch-install-scripts named pacstrap without the -i flag, which causes Pacman to not wait for user input during the installation process.

When blacklisting base group packages by adding them to the IgnorePkg line in ~/archlive/pacman.conf, Pacman asks if they still should be installed, which means they will when user input is bypassed. To get rid of these packages there are several options:

  • Dirty: Add the -i flag to each line calling pacstrap in /usr/bin/mkarchiso.
  • Clean: Create a copy of /usr/bin/mkarchiso in which you add the flag and adapt ~/archlive/build.sh so that it calls the modified version of the mkarchiso script.
  • Advanced: Create a function for ~/archlive/build.sh which explicitly removes the packages after the base installation. This would leave you the comfort of not having to type enter so much during the installation process.

Installing packages from multilib

To install packages from the multilib repository simply uncomment the repository in ~/archlive/pacman.conf:

pacman.conf
[multilib]
SigLevel = PackageRequired
Include = /etc/pacman.d/mirrorlist

Adding files to image

Note: You must be root to do this, do not change the ownership of any of the files you copy over, everything within the airootfs directory must be root owned. Proper ownerships will be sorted out shortly.

The airootfs directory acts as an overlay, think of it as root directory '/' on your current system, so any files you place within this directory will be copied over on boot-up.

So if you have a set of iptables scripts on your current system you want to be used on you live image, copy them over as such:

# cp -r /etc/iptables ~/archlive/airootfs/etc

Placing files in the users home directory is a little different. Do not place them within airootfs/home, but instead create a skel directory within airootfs/ and place them there. We will then add the relevant commands to the customize_airootfs.sh which we are going to use to copy them over on boot and sort out the permissions.

First, create the skel directory:

# mkdir ~/archlive/airootfs/etc/skel

Now copy the 'home' files to the skel directory, e.g for .bashrc:

# cp ~/.bashrc ~/archlive/airootfs/etc/skel/

When ~/archlive/airootfs/root/customize_airootfs.sh is executed and a new user is created, the files from the skel directory will automatically be copied over to the new home folder, permissions set right.

Similarly, some care is required for special configuration files that reside somewhere down the hierarchy. As an example the /etc/X11/xinit/xinitrc configuration file resides on a path that might be overwritten by installing a package. To place the configuration file one should put the custom xinitrc in ~/archlive/airootfs/etc/skel/ and then modify customize_airootfs.sh to move it appropriately.

Boot Loader

The default file should work fine, so you should not need to touch it.

Due to the modular nature of isolinux, you are able to use lots of addons since all *.c32 files are copied and available to you. Take a look at the official syslinux site and the archiso git repo. Using said addons, it is possible to make visually attractive and complex menus. See here.

UEFI Secure Boot

If you want to make your Archiso bootable on a UEFI Secure Boot enabled environment, you must use a signed bootloader. You can follow the instructions on Secure Boot#Using a signed boot loader.

Login manager

Starting X at boot is done by enabling your login manager's systemd service. If you know which .service file needs a softlink: Great. If not, you can easily find out in case you are using the same program on the system you build your iso on. Just use:

$ ls -l /etc/systemd/system/display-manager.service

Now create the same softlink in ~/archlive/airootfs/etc/systemd/system. For LXDM:

# ln -s /usr/lib/systemd/system/lxdm.service ~/archlive/airootfs/etc/systemd/system/display-manager.service

This will enable LXDM at system start on your live system.

Alternatively you can just enable the service in airootfs/root/customize_airootfs.sh along with other services that are enabled there.

If you want the graphical environment to actually start automatically during boot make sure to edit airootfs/root/customize_airootfs.sh and replace

systemctl set-default multi-user.target

with

systemctl set-default graphical.target

Changing Automatic Login

The configuration for getty's automatic login is located under airootfs/etc/systemd/system/getty@tty1.service.d/autologin.conf.

You can modify this file to change the auto login user:

[Service]
ExecStart=
ExecStart=-/sbin/agetty --autologin isouser --noclear %I 38400 linux

Or remove it altogether to disable auto login.

Build the ISO

Now you are ready to turn your files into the .iso which you can then burn to CD or USB:

First create the out/ directory (optional, build.sh will create it if nonexist),

# mkdir ~/archlive/out/

then inside ~/archlive, execute:

# ./build.sh -v

The script will now download and install the packages you specified to work/*/airootfs, create the kernel and init images, apply your customizations and finally build the iso into out/.

Rebuild the ISO

Rebuilding the iso after modifications is not officially supported. However, it is easily possible by applying two steps. First you have to remove lock files in the work directory:

# rm -v work/build.make_*

Furthermore it is required to edit the script airootfs/root/customize_airootfs.sh, and add an id command in the beginning of the useradd line as shown here. Otherwise the rebuild stops at this point because the user that is to be added already exists FS#41865.

Tango-edit-clear.pngThis article or section needs language, wiki syntax or style improvements. See Help:Style for reference.Tango-edit-clear.png

Reason: typo? (Discuss in Talk:Archiso#)
! id arch && useradd -m -p "" -g users -G "adm,audio,floppy,log,network,rfkill,scanner,storage,optical,power,wheel" -s /usr/bin/zsh arch

Also remove persistent data such as created users or symlinks such as /etc/sudoers.

Tango-view-fullscreen.pngThis article or section needs expansion.Tango-view-fullscreen.png

Reason: Report more data that needs to be removed or reset. (Discuss in Talk:Archiso#)

Rebuilds can be sped up slightly by editing the pacstrap script (located at /bin/pacstrap) and changing the following at line 361:

Before:

if ! pacman -r "$newroot" -Sy "${pacman_args[@]}"; then

After:

if ! pacman -r "$newroot" -Sy --needed "${pacman_args[@]}"; then

This increases the speed of the initial bootstrap, since it does not have to download and install any of the base packages that are already installed.

Using the ISO

See the Installation guide article for various options.

See also

Documentation and tutorials

Example customization template

Creating a offline installation ISO