Serial console on /dev/ttyS0

[Olof Tångrot <olof.tangrot@omicron.se>]

Hi there.
I need to have the ability to log on to an USB-memory live system from
the serial console. So I uncommented the following line in inittab (of
the compressed squashfs file system):

#T0=:23:respawn:/sbin/getty -L ttyS0 9600 vt100

After boot that linte in inittab mysteriously becomes:

T0:23:respawn:/bin/login -f user </dev/tty >/dev/tty 2>&1

Which yiels a lot of the following (and other annoyancies on the system
console):

"T0" respawning to fast: diabled for 5 minutes.

Nor is it not possible to login on ttyS0.

This line seems to fix this:

T0:23:respawn:/bin/login -f user </dev/ttyS0>/dev/ttyS0 2>&1

But it does of course not persist a reboot.

What mechanism rebuilds inittab?

How can I make a proper change to the compressed filesystem that works
as intended?

Regards

Olof