It's the first time I try to install MorphOS 3.20 via USB (because I don't have any blank CDs left), but I couldn't find a way to do so.

What I did:
- Download the USB boot image from morphos-team.net (morphos-3.20-hybrid.hdimg)
- Write the image on a 4GB-USB-Stick (sudo dd if=morphos-3.20-hybrid.hdimg of=/dev/rdisk4 bs=4m)
- The USB-Stick is recognized by my MorphOS 3.18 installation, but unfortunately you can't do the install from there (see attached screenshots)
- When entering the Boot-Menu of the Mac (pressing the "alt" key) there is no USB-Stick from where I could boot
- Using Open Firmware I didn't succeed booting from the USB stick, the documentation (https://www.morphos-team.net/guide/usb-boot) is very strange, because it descibes how to create a new boot media and there isn't any reference to the .hdimg-file you downloaded before.

ME1DM7NJ_t.jpg ME1DM7NK_t.jpg

I'm not even sure if you can USB boot a Mac from the .hdimg (never managed to boot any PPC-Mac from USB).
The error message shows that you still loaded the boot.img from HDD which is 3.18 and won't do for install.

IMO the best way to go would be to download the .iso and follow those instructions from step 1.

Quote:

Afair I always did use ISO on Mac's but to be honest, morphos.net says MAC on hdimage, so there might confusion coming from?

Well the .hdimg is SFS so OSX or OF won't be able to read it.

It should be possible to place the mac_ppc32 boot.img on the boot: partition of the HDD (that can be read by OF) them manually boot the file from OF. Once it is started it should see the USB stick as a bootable device (similar to what is seen in OP's error message) and just boot.

Quote:

It isn´t strange. Only it is complete docs, including formatting the flashdisk. It is not allways needed.
1. download morphos-3.20.iso, not .hdimg
2. Take standart formated flashdisk (Fat32 or so )
/ or take your flashdisk with hdimage and format it again with Win machine
/ or format it in MorphOS exactly as described here.
3. copy morphos-3.20.iso to flashdisk as morphos.iso
4. mount/open .iso, from there open /mac_ppc32/ directory and copy boot.img to flashdisk
5. on flashdisk you should have morphos.iso and boot.img
6. continue here

Quote:

I do the updates always w/o a stick via the iso on hdd, here's how:
https://deyaneya.de/bckrs/MorphOS/morphos_update.html

Installed on my PegII via USB stick and all is ok.
I'll try later on my Mac mini (silent upgrade version) via USB and will give you a feedback.

Thanks a lot for all your quick replies!

I succeeded using the quick & dirty way:
1. Writing the .hdimg file to a blank USB stick (via dd, see my first comment)
2. replacing the boot.img on my MorphOS 3.18 system with the new 3.20 boot.img from the stick
3. reboot the Mac Mini with the USB stick plugged in
4. Then the welcome screen appears (without iPrefs error message, because the kernal version matches) and you can start the installer and choose a new install

I know this isn't the recommended way to install MorphOS, but booting from the stick didn't work, whatever I tried and this method worked like a charm.


[ Edited by hiTCH-HiKER 07.06.2026 - 09:16 ]

It should be possible to just press and hold the option key on reboot to open the graphical boot menu and select the usb stick from there.

Quote:

I tried that, but only the hdd shows up there, no USB stick.

I got my mac mini g4 installed from booting the usb. (my base install was 3.14)

1 - write to usb (sudo dd if=/tmp/morphos-3.20-hybrid.hdimg of=/dev/sdc bs=4M)
2 - I used a old logic tech g15 keyboard that has a usb hub in it, so put the usb into the keyboard, and put keyboard + mouse into the mac mini g4
3 - boot to OF (windows+alt+o+f)
4 - find the usb disk in the device tree, for me it was

the '>'is the OF command line (dont type the > part )

> dev /
> ls (see device tree)
(I see keyboard on usb0, you might see it on usb1?)
> dev usb0
> ls
(I see it has a disk in the tree)
> dev hub@1
> dev disk@3
> pwd
(it spits out the proper device tree path)
pwd pci@f2000000/usb@1b,1/hub@1/disk@3
so use that as the boot path
> boot pci@f2000000/usb@1b,1/hub@1/disk@3:,\\tbxi
(screen flash, it throws like an error, press cursor up and enter to run the same command again and it works, i tested this 3 times in a row and it always works on the second boot command).

takes a long time (its probably usb1.1 or something on my keyboard hub).