Table of Contents
The configuration is divided into two files,
syslinux.cfg defines the place where
leaf.cfg can be found during boot process. The
packages to load and the devices to load from are defined in
leaf.cfg.
Because leaf.cfg is sourced by
linuxrc it is necessary to be aware of linefeed
handling.That means you can break leaf.cfg, if you
edit it with a Windows editor like notepad. A possible solution is to
use a decent editor like e3 or to run the DOS2UNIX utility, which strips
the <CR> chars. It works under pure DOS as well as a DOS box under
XP (and I would expect 9x, ME, 2K, NT as well). It can be downloaded
from: http://gatekeeper.dec.com/pub/micro/pc/simtelnet/msdos/txtutl/dos2unix.zip
Opposed to all previous versions there must be neither packages nor devices defined in syslinux.cfg. You will have to configure the LEAFCFG variable instead.
The variable has the following syntax: LEAFCFG=/dev/device[:filesystem]
Any specified filesystem is tried first. If no filesystem is specified, or a mount using the specified filesystem fails for any reason, all filesystems currently enabled in the kernel (entries in /proc/filesystems that do not start with 'nodev') will be used to try to mount the configuration device.
For a floppy it could be LEAFCFG=/dev/fd0u1680:msdos; for a harddisk something like LEAFCFG=/dev/hda1:msdos, for a CD-Rom it could be LEAFCFG=/dev/cdrom:iso9660.
Variables that may be set in leaf.cfg
include:
VERBOSE - (if non-null enables additional output from linuxrc
LRP - Packages to load
PKGPATH - Device(s) to load packages from
syst_size - Size of root ramdisk
tmp_size - Size of /tmp ramdisk
log_size - Size of /var/log ramdisk
CONFIGDB - name of the config database (Default: configdb.lrp)
MODDB - name of the modules database (Default: moddb.lrp)
Note that spaces, tabs, newlines, or commas may be used to separate entries in the LRP and PKGPATH variables.
Below an example from the base image:
LRP="root config etc local modules iptables dhcpcd keyboard shorwall ulogd dnscache dropbear weblet" PKGPATH="/dev/fd0u1680:msdos" syst_size=6M log_size=2M
It's still possible to use "LRP" and "PKGPATH" in syslinux.cfg, they can be extended in leaf.cfg by doing: LRP="$KCMD_LRP extrapackage" and PKGPATH="$KCMD_PKGPATH,/dev/mydev:newfs".
Variables available for use in the leaf.cfg script include any kernel command line parameters (prefixed by KCMD_), the mount point of the LEAFCFG device (MNT), and available filesystems (FILESYSTEMS). See the linuxrc script for full details. Note that the leaf.cfg file is processed *BEFORE* any packages are loaded (in fact, before the package path and package list are finalized), so it would be possible, for example, to load any kernel modules or other software directly off the LEAFCFG= device required to read package files off of attached devices. It is only necessary to have support for the LEAFCFG= device either compiled into the kernel, or included in the /boot directory of the initial ramdisk.
In addition, the leaf.cfg file is sourced as a shell script, allowing the potential for extention of the leafcfg scripts without requiring a modification of the physical boot media (ie: anything from:
echo "Hi Mom!"
to:
insmod $MNT/MyWierdDevice.o --with-parameters
insmod $MNT/NewFileSystem.o
mknod /dev/mydevice -b 123 231
PKGPATH="$KCMD_PKGPATH,/dev/mydev:newfs"