Hi!
25-Июл-2005 18:08 [EMAIL PROTECTED] (Alain) wrote to
[email protected]:
>> IMO, scince FS, GS, and the high parts of EAX,... aren't used by MSDOS
>> as well, drivers can get away when they destroy these resisters,
>> so it's a good idea to save them as well.
A> This gets complicated when Kernel is 386 optimized. MS-DOS never
A> modified this because it is 16-bit. It could be argued that if a kernel
A> is to be compatible it cannot modify them either.
Kernel preserves all registers (including 32-bit parts), which
shouldn't be modified from applications point of view.
A> Now the other way round: can the kernel be sensistive to 386 registers
A> being modified by drivers? IMHO not,
But it is.
A> because the original one is not and hence some drivers will stop working.
A> Then I believe that it is the kernel resposibility to preserve it's
A> registers.
- if kernel is 16-bit target (ie, for 8086 also), then it _can't_ preserv
32-bit registers (including fs/gs).
- because 16-bit kernel can't preserve 32-bit registers, but it not uses
them itself, then by bug in emm386 will be affected applications (like
WDOSX), which call driver explicitly or implicitly through kernel.
A> But it is nice to have EMM386 to preserve them too :)
This is not only nice, this is required!
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