Hi Bret, thanks for the great summary!
For awhile, the UEFI manufacturers provided a CSM (Compatibility Support Module) as the "translation layer" so you didn't need a VM. But they've even stopped doing that nowadays. So, we'll either need to come up with a "generic CSM" that doesn't need a VM but still provides the needed level of hardware support both now and in the future, or we'll need to do some kind of "thin VM" as Jerome is suggesting. I think the second option has a better chance of long-term viability even though I would prefer the first.
My impression based on earlier discussions and/or BTTR forum threads would be that there are "open source BIOS" initiatives which could be a starting point for a large point of a "generic CSM" (BIOS module to load on UEFI systems before booting DOS, with some magic glue needed) at least for actually more aspects of the BIOS than normal DOS and DOS apps will require :-) I can imagine that the dosemu2 people also have interesting expert thoughts about that and those magic glue problems involved. Depending on how thin the glue and VM layer will be, you will be able to run fewer or more DOS apps with it. You can run some DOS apps in CTTY serial consoles if they only use int 21 for user I/O. There are support modes for simple DOS apps in some boot managers which only implement a few most popular bits of the DOS API to run apps directly from the boot manager without an actual DOS. So why not use for example real mode DOS apps without sound, with whatever is left in terms of hardware text mode or maybe VGA as an already entertaining intermediate milestone and keep more VGA, VESA, PC speaker, mouse, protected mode apps etc. pp. for later? The "easy" solution will still be running a DOS-friendly VM inside Linux or other host OS. But not the exciting solution regarding technological challenge and "abstraction thinness". People have written hypervisors to hide malware. Porting an open BIOS and some VM ingredients into a CSM and an open source "VMware ESXi" competitor which runs DOS better than the commercial product does? In other words, a Xen for DOS? To stay in the Xen terminology, would one want a paravirtualized DOS for that? Or would one put some light weight "BIOS setup" type menu into dom0 and run DOS only as client? Wikipedia mentions Alpine Linux offering a rather small Linux dom0. https://en.wikipedia.org/wiki/Proxmox_Virtual_Environment and KVM may also be an interesting combination to look at? Checking for others in https://en.wikipedia.org/wiki/Comparison_of_platform_virtualization_software my impression is that those Hypervisors which run on bare metal somehow tend to be either Linux specific or commercial and proprietary things? Regards, Eric _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
