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<h1><span><em>live Arch Linux</em> builder</span></h1>
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<h2 id="pagetitle" level="2">GUI Tab: Preparing the Medium</h2>
<p>This tab presents the various possibilities for installing the
<em>live</em> system that was built on the 'larchify' tab onto a bootable
device, which can be in <em>iso9660</em> form (to burn to a CD/DVD), or
a partition on a hard disk or flash storage device. A suitable bootloader
can also be installed. In addition the copying of a larch system from one
medium to another is supported and also the building of a boot-iso for
a USB device.
</p>
<h3>Bootloader</h3>
<p>To keep things simple only the <em>syslinux</em> family of bootloaders is
supported. This allows booting from CD/DVD (<em>isolinux</em>) and partitions
formatted with 'ext2/3/4' or 'btrfs' (<em>extlinux</em>) or with 'vfat'
(<em>syslinux</em>).
</p>
<h3><a name="bootlines"></a>Boot entries/options</h3>
<p>The bootloader offers a selection of 'boot lines', so that
different systems, or various kernels in combination with various
boot options can be started. The file 'cd-root/boot/bootlines' in the profile
contains this information for the <em>larch live</em> system in a
form which can be converted automatically into bootloader specific
formats. This allows the boot menu entries to be supplied in the
profile in an easily parseable way which is independent of the actual bootloader
which is used in the end. The format should be pretty clear from
the default version.
</p>
<p>The 'bootlines' file covers only the menu entries for the
<em>larch live</em> system. All other entries must be supplied in
a bootloader specific 'template' file. A button is supplied to edit
this, too. Note the '###LARCH' line, which specifies where the
information from the 'bootlines' file is to be included.
</p>
<h3>The 'cd-root' directory</h3>
<p>The handling of this directory is described
<a href="profiles.html#cd-root">here</a>. It allows customisation of
files on the medium which are not directly used by <em>larch</em>, but
can be useful in certain circumstances. You could, for example, include
a package repository, or just about any data files needed by the
specific <em>live</em> system. The default settings might well be
adequate for many purposes.
There is a button to open a file browser on this directory
(within the current profile).
Note that only the '/boot' and '/larch' directories of the medium are
available for customisation, so in general any application data should
be placed in the '/larch' directory.
</p>
<h3>Choice of build medium</h3>
<p>The main choice is between a partition (on a hard-disk, USB-stick, etc.)
and an <em>iso</em> file (for writing to a CD/DVD). It is also possible to
build a 'boot-iso' (to burn to a CD) for an already prepared <em>larch</em>
USB-medium, to enable booting on older systems which don't support booting
from USB.
</p>
<p>The destination can be changed by clicking the button - a menu appropriate
to the type of destination appears (note that for destination partitions
only unmounted ones will be shown).
</p>
<h4>Build an <em>iso</em>, for CD or DVD</h4>
<p>Only limited customisation possibilities are offered here, you can
set the volume label ('-V' option to <em>mkisofs</em>). The boot CD is
discovered at boot by searching for '/larch/system.sqf'.
</p>
<h4>Install to partitition</h4>
<p>Here one must select the partition to install to - which must be
plugged in and not mounted (good luck to automounters!), and
also select how the <em>live initramfs</em> is to find the correct
partition. The available options are:
<ul>
<li>Partition: The device will be sought on the basis of its (current)
device name - such as /dev/sdb1. This is only suitable if you can be
sure the device will always get the same name (which - especially with
pluggable devices - is unlikely).</li>
<li>UUID: Each device normally has a unique UUID, so this is a pretty
reliable method. It's just that the UUIDs themselves are rather ungainly
and unmemorable.</li>
<li>LABEL: Booting on the basis of the device label can be quite reliable
and quite readable, so it might be a good compromise. This is the
recommended choice.</li>
<li>Search (for larchboot): The <em>live initramfs</em> tests all
visible devices until it finds one containing the file larch/larchboot.
</li>
</ul>
</p>
<p>The partition will be formatted with 'ext4', and you can choose whether
to use the journalling feature of this file-system.
No other file-system types are supported at present (though by formatting
exernally and using the 'Don't format' option it is possible to use
another one, so long as it is supported by <em>syslinux/extlinux</em>).
The option to install without formatting should only be used by people who
know what they are doing, in general it is <strong>not</strong> recommended.
Another option for experts is the suppression of the installation of the
bootloader to the Master Boot Record of the <em>live</em> medium. If you
don't install to the MBR, you will need to provide some other means of
booting the device, but in certain circumstances this could be a useful
option.
</p>
<p>The option 'Not bootable via search' suppresses the generation of the
'larch/larchboot' file, so that the method of medium detection which
searches for this file will not work on the generated medium (this of
course makes no sense if the 'Search (for larchboot)' medium detection
method is selected for this medium).
</p>
<h4>Create boot iso</h4>
<p>In this case the <em>source</em> medium - a partition containing the
<em>larch</em> system (presumably on a USB device) must be selected,
by clicking on the button in the source frame. Only unmounted partitions
with volume labels will be offered. A small <em>iso</em> file with just
the kernel and initramfs, plus the necessary bootloader files, will be
created. This is to cover cases where a machine cannot boot from USB
devices, but can boot from a CD.
Note that the USB device for which the CD is to be generated must be
plugged in, but not mounted.
</p>
<h3>Volume label</h3>
<p>The maximum length of the label should be 16 characters, which is ok
for both 'iso' (CD/DVD) and for 'ext4'.
</p>
<h3>Write the larch medium</h3>
<p>When enough information is available, this button will be enabled and
the generation can be started.
</p>
<h3>Copying larch media</h3>
<p>By choosing a medium (iso-file or labelled partition) in the source
frame, it is possible to copy this system to another medium. Certain
aspects of the destination device can be set just as in the initial
creation process. When a device or iso-file is selected as source a
simple validity check will be performed on it, a failure resulting in
the selection not being accepted.
</p>
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