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Re: VBE:in real mode or in protected mode
Posted: Tue Mar 16, 2010 12:08 am
by shindow
I jump to vm86 mode,but when i execute int 3(it gets the from the vector table as in real mode do),let's say 0xff57.if i am in real mode ,it is okay,i don't know why it will judge the GDT's limit.The pic is as follows:
Re: VBE:in real mode or in protected mode
Posted: Tue Mar 16, 2010 3:45 am
by Combuster
Virtual 8086 mode traps back to protected mode when provoked, so that emulation software may do what would otherwise be done on real hardware. Interrupts are one such example.
Even so, your IDT/TSS is broken because it wants to load protected mode segments that doesn't exist.
P.S. please do post the log in plaintext next time.
Re: VBE:in real mode or in protected mode
Posted: Tue Mar 16, 2010 7:28 pm
by shindow
Thank u,Combuster
Combuster wrote:Virtual 8086 mode traps back to protected mode when provoked, so that emulation software may do what would otherwise be done on real hardware. Interrupts are one such example.
Do you meaning that(commonly),if interrupts or exeception happens it always jump to protect mode,so it will jugde the GDT's limit?
Combuster wrote:
P.S. please do post the log in plaintext next time.
I am sorry for that,i cannot copy the text from the bochs.I will pay attention next time.
My problem is solved yesterday,i find that if you set CR4.VME bit,it seems that you can use int n like in real mode,it works.
Thank you for all again!