Re: kvm86 kernel option
Jean-Yves Migeon <jeanyves.migeon <at> free.fr>
2012-05-08 15:22:58 GMT
Le 08/05/12 11:36, David Laight a écrit :
> Does anyone use (or have used in the last n years) the i386
> kernel VM86, KVM86 or KVM86DEBUG options that (I think) allows
> 16bit user programs to run within a 32bit kernel?
Yes. It allows a program to make 16 bits calls, for example to BIOS.
> My suspicions are that, if it ever worked, it will have bitrotted
> out of existance!
What makes you think that?
> Deleting it seems to be a good idea.
I am all for dumping 16 bits compat code, but please remember that
bioscalls may be needed by programs like X (setting video mode comes to
It injects also a few problematic features, like allowing code to be
mapped at NULL (0x0) (required for v8086 to work properly).
I would suggest commenting out the option from GENERIC, and see if X
still works ok with different cards, or old drivers (vesa(4)).
NetBSD does not implement all the latest and greatest DRI2/GEM/KMS, so
better keep code that can still be used by old systems like VESA.
> Possibly wine uses it for 16bit windows code?
Dunno if wine uses it. For DOS and 16 bits mode, dosbox emulates it just