@Lio
I guess if you can mount an iso under OS4 you might be able to use the a line like this in your CD32 E-UAE config.
filesystem2=ro,CD0:CD0:XX0:,0 instead of scsi=true
Where XX0 is the OS4 device name of your mounted ISO.
I tried mountiso from aminet but it does not work under OS4 however, it can be used to mount an iso this way though which may or may not help you.
Firstly I just created an ISO of pinball illusions on the PC. Its 515MB so to get it over to Amiga I stuck it on a USB Memory Stick.
Now to make that USB Memory stick visable to AmigaOS under E-UAE add the following line(s) to your E-UAE config.
filesystem2=rw,USB0:USB0:USB0:,0
filesystem2=rw,USB1:USB1:USB1:,0
Here my USB memory stick is USB1:
Then we need to mount the ISO using mountiso mentioned above for reference grab it from here:-
http://aminet.net/docs/help/MountISO.lhaUnpack this to a filesystem thats visible under E-UAE.
In your AmigaOS E-UAE enviroment copy
filedisk.device to devs
SimCD0 + icon to devs:dosdrivers
You might need to edit the SimCD0 mountlist as it defaults to l:cacheCDFS for it file system. Thats ok here as my 3.X partition is taken from AF2006 DVD set which uses CacheCDFS.
Now edit the Unit tool type via the SIMCD0 ICON
EG: for me The Unit is USB1:Pinball.iso
Now mount SIMCD0
And you now have a CD32 iso mounted under E-UAE from a USB memory stick