Configure the IVT to use in protected mode!!

[mahmoudaladawi]

Hi all,
I want to know why don't we use the IVT segment:offset data in the table of extended bios interrupts to build interrupt descriptors that call the same routine in protected mode???
i.e calling bios functions by descriptors instead of vector table??
Is this possible??

Thanks for help in advance.

[bluemoon]

The intel manual says you need IDT, not IVT, for protected mode, therefore we don't use IVT.
Read chapter 6 of IA-3A.

i.e calling bios functions by descriptors instead of vector table??

You need to do it v86 mode or temporary switch back to real mode, as BIOS routine assumes real mode addressing.
But then, if you have your own drivers you probably enjoy to operate under protected mode than real/v86 mode.

[mahmoudaladawi]

Sufficient answer. Thank you