Again, sorry for the top-down mail. There will be a patch just as soon as I get a bit of spare time (this weekend might be a good opportunity). All I have now is a hack that will work for my system under well-known conditions.
Cheers, Bogdan ----- Original Message ---- From: Robert Millan <r...@aybabtu.com> To: The development of GRUB 2 <grub-devel@gnu.org> Sent: Fri, October 9, 2009 8:55:02 PM Subject: Re: Fw: 16-bit bootloader support? On Fri, Oct 09, 2009 at 02:21:06AM +0200, Vladimir 'phcoder' Serbinenko wrote: > Bogdan wrote: > > The difference is basically that you have no paging, the linear address is > > the same as the physical address, no virtual 8086 mode, no way of going > > back to real mode, the segment address inside the descriptor table is 24 > > bits wide and the limit is 16 bits wide. > > > > In response to Seth - there are still business and apparently research > > machines out there that still use the 80286. It's arguable whether one > > would actually need to be able to boot several OSes on such machines > For multi-OS on pre-386 use mbrldr (mbrldr.sf.net) > > but I am an example of someone who is personally interested in this. If I > > write support for this can it be merged into GRUB > Rule of a thumb is "if you do it in a way it doesn't create a > maintenance burden then it can be merged". Due to limited usefullness > the amount of maintenance burden I'm ok to tolerate is small. I would > define 286 as a separate architecture with perhaps some BIOS-related and > realmode code reusage. This way it minimises the amount of it getting in > the way > Due to 16-bit pointers it's still likely to get in the way of a lot of > code. Also even before you start you have to ensure grub2 can work with > less than 1 MiB of memory. > In whole I would say that maintaining 16-bit compatible code is a burden > and probably not worth if only PC 286 is considered. Additionally > without being able to load any kernel natively grub's usefulness > decreases. Many other modules become useless too because newer standards > aren't supported on 286 hardware. In whole I feel like multi-OS on 286 > and 8086 niche is well filled by mbrldr. > (but I'm not maintainer) I have very limited interest in this. But if there's real demand (i.e. not just a toy) and it doesn't mean more work for us, we could accept it. Is there a proof-of-concept patch? -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all." _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
