Hi, > On Jan 22, 2023, at 4:37 PM, Liam Proven <lpro...@gmail.com> wrote: > > On Sun, 22 Jan 2023 at 22:11, Jerome Shidel <jer...@shidel.net> wrote: >> >> Assuming Google does not scrap GSoC amidst the layoffs, I have a thought. >> >> Perhaps it could be used to solve one of the most frequent problems I hear. >> Running FreeDOS on modern UEFI hardware. >> >> As we are all well aware, this cannot be directly accomplished and would >> require an abstraction layer between the OS and the actual hardware. > > I was discussing this recently on Mastodon, following Jim kindly > agreeing to a video interview for the Register. > > https://social.vivaldi.net/@do...@nd2.uk/109716078029851572 > > This is a very sketchy thought, but... > > AIUI, the way that 386 memory managers for DOS work is that they put > the CPU into protect mode, map RAM into upper memory blocks as DOS > wants, then start a single, non-multitasking V86 mode VM for DOS > itself. > > That basic process would be enough to boot a DOS instance, wouldn't it? > > "All" it needs is a memory manager that can start as a 32-bit process, > set up a few interrupts -- INT 11 for the hard disk, for instance -- > start a single V86 process, and then kick DOS off in that process. > Then a stub program for DOS to load in CONFIG.SYS to enable the memory > manager. > > Normally, DOS starts EMM386 or JEMM386 or whatever. This way round, > JEMM386 starts DOS. > > Does that seem doable? > > It needs to be small, but as such, I wonder if VisOpySys, KolibriOS, > MenuetOS or the like might have something usable? > >> A project could be created to provide a very thin Linux based system >> (possibly using an RTOS kernel) whose only job is to manage the abstraction >> layer and implement the virtual machine to run FreeDOS. > > This sounds akin to the process HP and others use to ship FreeDOS laptops. > > It works but it's quite complicated: > > https://blog.tmm.cx/2022/05/15/the-very-weird-hewlett-packard-freedos-option/ > <https://blog.tmm.cx/2022/05/15/the-very-weird-hewlett-packard-freedos-option/>
There are many similarities. But, overall not really. Basically, HP is just running linux and starting a Virtual Machine image that has FreeDOS installed. For all purposes, it is just linux faking DOS using a Virtual Machine. There isn’t anything wrong with that. But, it is not what I’m thinking. I'm thinking more along the lines of how SYSLINUX / MEMDISK work, which we use on the LiveCD to boot FreeDOS on more recent hardware that have problems with the LegacyCD. The LegacyCD just uses the original El Torito specification without SYSLINUX/MEMDISK. All BIOS based systems should boot the LegacyCD. But, that is not the case. Many modern machines fail to boot it. I think that is probably caused by lack of testing or only partial implementation of the spec on their part. Similar to PC speaker support in most Virtual Machine platforms, it may just not be there. There could be a small image containing a thin linux host that is booted by system. Possibly in it’s own partition or image file. This host then provides an abstraction layer which then boots the system like it was a PC with a legacy BIOS. Most likely providing a some abstracted and emulated hardware like a SoundBlaster compatible audio card. The Client OS (FreeDOS) would be installed to a normal partition on the drive. Providing support to also map things like I/O ports from the host OS to the client, to allow the possibility of connecting real legacy hardware to the machine (like CNC machines and TTY devices). :-) Jerome On a side note... I think we should probably discontinue the LegacyCD. There is only a very narrow range of hardware that can boot the LegacyCD but cannot boot the LiveCD. That hardware has an extremely high probability it will also have a 1.44 floppy diskette drive. That floppy drive can be used to boot the LiveCD. Like I said, it is a very small range of hardware and would effect very few users. It is more effort to maintain, distribute and explain than it is worth. Also, it would eliminate any confusion on “which” CD image to download. The user would just download the LiveCD and either it boots directly or they use the included floppy boot image. > > -- > Liam Proven ~ Profile: https://about.me/liamproven > Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com > Twitter/LinkedIn: lproven ~ Skype: liamproven > UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 > > > _______________________________________________ > Freedos-devel mailing list > Freedos-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freedos-devel
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