[sskras]

... and with other obscure OSes too.

That's why after all these years I am still interested in the Firmware or the hypervisor level emulation of the optical drive.

Maybe by even including the whole virtual storage controller (like Adaptec 29160N SCSI Card), OpROM on which could support boot seamlessly for most BIOS or UEFI firmwares.

And which would be supported by most PC OSes including some more obscure like MS-DOS, OpenBSD, Solaris 10, BeOS, MorphOS.

(Or maybe by trying to integrate the emulated ODD subsystem into physical USB stack. Which I guess would be a lot more difficult)