[Q] Dual-booting AmigaOS 3.9 and 4.1

[mousehouse]

Hello all,

After quite some struggles I have managed to install "AmigaOS4.1 for Classic" on a second hard disk in my Amiga but I cannot get it to run/boot properly.

System has two HD's and a SCSI CDROM connected to the cybppc.device. Harddisks have SCSI id's #0 and #2, the carom has id #1. Now, the first hard disk (id#0) has one FFS partition with my OS3.9 install on it, runs great. I have managed to install 4.1 on a FFS partition on drive #2, and added the later FFS and SFS filesystems during install. Now I have given the 3.9 partition the highest boot priority (4) because I want to boot that by default.

The newer FFS version on the second drive is confusing my primary boot partition. My guess is that the FFS gets loaded when the RDB is scanned at boot time, and that the newer FFS does not work properly with the 3.9 ffs partition. I need to disable one of the two drives in the CSPPC SCSI BIOS to get it running... but I can live with that for now...

How can I setup the system to dual-boot properly? Can I boot 4.1 from 3.9 just like with the install? Is there a tool or script that preloads the necessary stuff to do this? Or is there a "LILO" like boot loader that gives me a boot menu?

[Thomas]

If you installed it correctly, the new FFS should have an identifier of DOS\7 (a.k.a. 444F5307) and the older FFS is DOS\3 (a.k.a. 444F5303), so they should not interfere. However, if you use the early startup menu to select a boot partition you need to do this twice because each of the systems reboots once on power-up.

[Cass]

If you installed it correctly, the new FFS should have an identifier of DOS\7 (a.k.a. 444F5307) and the older FFS is DOS\3 (a.k.a. 444F5303), so they should not interfere. However, if you use the early startup menu to select a boot partition you need to do this twice because each of the systems reboots once on power-up.

Actually you may skip the OS4 partition selection for a second time, if you add the "MODULE Kickstart/BootDevice" entry in the  Kickstart/Kicklayout file, by typing
Echo >Kickstart/BootDevice "DH2"
(assuming DH2 as the OS4 partition).
Once in OS4, you may reset and boot again in OS4 with no ESM selection. To return in 3.x, just keep pressed Ctrl+A+A for a few seconds ;-)

[Matt_H]

Actually you may skip the OS4 partition selection for a second time, if you add the "MODULE Kickstart/BootDevice" entry in the  Kickstart/Kicklayout file, by typing
Echo >Kickstart/BootDevice "DH2"
(assuming DH2 as the OS4 partition).
Once in OS4, you may reset and boot again in OS4 with no ESM selection. To return in 3.x, just keep pressed Ctrl+A+A for a few seconds ;-)

I use this method (albeit for 4.0 Classic). Works great!

[Doraemon]

I use this method (albeit for 4.0 Classic). Works great!

Me too in 3.9 / 4.1
Bootdevice is the trick