GUI Tab: Larchify

You can repeat the 'larchify' command as often as you like, to test various configurations or to build differently configured live systems with the same underlying packages. This works because the 'larchify' process itself does not change anything within the installation - all the files it generates are placed in the 'overlay', which (thanks to aufs) will just cover up any old versions of the added files in the underlying installation. At present larch does not support the 'deletion' of installation files, they can only be overlayed by replacements.

User accounts

You can enter or edit user accounts to be added during the creation of the live system. Any of the columns except the first (the login name) may be empty.

A password can be set for the new user by entering this (plain text - I'm guessing this is alright in this situation ...). An empty password field will allow passwordless logins (at least on the console).

The primary group of a new user can be set in the 'Group' column. When this is empty, it takes the useradd default, which is defined by settings in '/etc/login.defs' and '/etc/default/useradd'. Note that the default in Arch Linux is a group with the same name as the user, this is set by 'USERGROUPS_ENAB yes' in 'etc/login.defs'. You can override this by adding an 'expert' option, or by placing a modified version of this file in the profile's 'rootoverlay' directory.

By default the UID number will be chosen automatically, but a specific number may be entered here. In Arch Linux the UIDs normally start at 1000.

The 'skel'-directory column determines how the user's home directory will be initialized. The default (empty cell) is to copy the contents from '/etc/skel'. The editor popup shows a list of the available alternatives (folders within the profile beginning with 'skel_').

The additional groups to which this user should belong can also be specified. Entries in this column are initialized to some default value which should be adequate for normal use, but may well need tweaking. This is a comma separated list without spaces.

The final column allows you to pass further options to the system 'useradd' command used to add the new user. Do not use double-quotes in this option string. Read 'man useradd' for more information about the available options.

Editing the table

Click on a cell in the selected row to cause an editor popup to appear. Clicking on an unselected row selects that row.

The kernel

By default the standard Arch kernel will be used in the live system, but it is also possible to use some other kernel, so long as it is suitably configured. In particular it must support squashfs and aufs. If you are using a non-standard kernel you need to tell larchify where it is (its file name within the /boot directory - the default is 'vmlinuz26') and the name of its mkinitcpio preset file (default 'kernel26'). These can be entered in the corresponding places in the advanced options section of the gui.

The overlay

Apart from the few customization options offered by the GUI directly, it is possible to include any files in the live system by adding them at the appropriate path within the overlay directory ('rootoverlay') of the profile. This button opens a file browser on the 'rootoverlay' directory of the current profile.

Locales

You can select the (glibc) locales supported by the live system by editing the /etc/locale.gen file in the overlay. If there is no such file initially it will be copied from the new installation's (not the host's!) version. See (for example) the Arch Wiki for more information about locales. Note that larch tries to leave the locale files in the installation itself unchanged, new files are placed in the overlay.

Arch configuration: /etc/rc.conf

This is the central configuration file for an Arch Linux system. You can edit it here (see for example the Arch Wiki for more information about this file).

Reuse existing system.sqf

After 'larchify' has been run, the base installation will have been 'squashed' into a compressed archive. Setting this option will prevent the repetition of this compression (which is quite a lengthy process) on the next run of 'larchify'. This should only be enabled if no changes have been made to the base installation (otherwise these changes will not be picked up).

Advanced options - the defaults are normally fine

mkinitcpio.conf

Here you can edit the mkinitcpio.conf used for building the initramfs for the live system. N.B. The details of mkinitcpio handling in larch are a bit complicated, so if you change something here please be careful - you are not editing '/etc/mkinitcpio.conf', but rather 'etc/mkinitcpio.conf.larch' in the 'rootoverlay' directory of the profile (see here for further details). Also, don't change the larch hooks.

ssh-keys

See ssh host keys. The default is to generate these keys (if the openssh package is installed).

Reuse existing locales

For people generating a lot of locales this can save a bit of time on a rerun, so long as nothing significant (like glibc, or /etc/locale.gen) has changed in the installation.

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