On 12/05/2017 01:22, Xu, Anthony wrote: >> SeaBIOS has a couple of different methods to accomplish this mode >> switching - it can directly switch modes (C16_BIG switch) or it can >> use a helper in SMM mode to perform the switch (C16_SMM). The >> preferred method is C16_SMM as C16_BIG isn't available in VM86 mode >> and it also clobbers the 16bit segment registers. > > Hi Kevin, > > Why does SeaBios use VM86 mode?
SeaBIOS doesn't, but for example old DOS extenders uses it. You can run Windows 95 inside SeaBIOS. Paolo > vtx supports real mode long time ago. > > C16_SMM is slow because it causes several extra switches between VM and QEMU. > I would prefer C16_BIG for better performance. > Does SeaBios know if it runs in real mode or VM86 mode? > Can SeaBios choose C16_SMM/C16_BIG based on VCPU mode? > > > Thanks, > Anthony > _______________________________________________ SeaBIOS mailing list [email protected] https://mail.coreboot.org/mailman/listinfo/seabios
