Hi,
This is explained in the manpage for init(1).
Quoting man init:
---cut---
BOOTFLAGS
It is possible to pass a number of flags to init from the
boot monitor (eg. LILO). Init accepts the following flags:
S, single
Single user mode boot. In this mode /etc/inittab is
examined and the bootup rc scripts are usually run
before the single user mode shell is started.
1-5 Runlevel to boot into.
-b, emergency
Boot directly into a single user shell without run
ning any other startup scripts.
---cut---
In LILO, this means that you have to specify the image that you want to
boot (most likely called linux, but actually depends on the entries in
your /etc/lilo.conf) and add additional parameters to init to that.
So, if you have two boot target images defined in /etc/lilo.conf, one
called linux and one called linux.old, you could boot the kernel specified
by linux.old into runlevel 2 by typing to the "LILO:" prompt:
linux.old 2
Cheers,
Joost
