How to multi-boot JUNOS on IBM T42[2]

INSTALLATION
INSTALL FreeBSD 4.X FIRST
Partition the disk as mentioned before and install minimum FreeBSD 4.X. Minimum installation is enough because JunOS will format it later.

PKG_ADD JINSTALL
After boot,
1. cp /boot/boot{0,1,2} to /var/tmp first.
2. pkg_add jinstall-XXX-modified
3. cp /var/tmp/boot{0,1,2} to /boot
4. reboot
This is because jinstall-XXX replaces /boot/boot{0,1,2} with its own version and during next boot, JunOS on T42 hangs at boot1. This could be hardware support problem on these boot code of JunOS. Luckily, using the original bootX solves the problem. You should be able to see the boot messages on the screen.

JunOS will install all its packages and reboot again automatically. After boot, congradulatoin, you have a JunOS laptop.

Annoying messages will keep pumping out until you save your first configuration.

FINAL STEP
Each boot, JunOS restores /etc/ttys to default, i.e. we cannot login from terminal. To solve this problem, cut the following code to /etc/rc.custom, which JunOS will execute in /etc/rc.local.
--------- CUT HERE BELOW: /etc/rc.custom -------------------------------------
#!/bin/sh
echo 'ttyv0 "/usr/libexec/getty Pc" cons25 on secure' >> /etc/ttys
echo "Restart INIT....."
kill -HUP 1
--------- END OF CUT --- -----------------------------------------------------

Now everything is done. Enjoy it.