VPICD_Convert_Int_To

VPICD_Convert_Int_To_IRQ

include vpicd.inc

mov eax, VecNum ; interrupt vector number

VxDcall VPICD_Convert_Int_To_IRQ

jc not_mapped ; carry flag set if vector not mapped to IRQ

mov [IRQNum], eax ; IRQ number

The VPICD_Convert_Int_To_IRQ service returns the IRQ number (if any) corresponding to the specified interrupt vector number.

Parameters

VecNum

Specifies an interrupt vector number.

Return Value

The carry flag is clear and the EAX register contains the IRQ number if the interrupt vector number is mapped to an IRQ. Otherwise, the carry flag is set.

Comments

Since virtual machines can map IRQ numbers of the virtual PIC to any interrupt vector numbers, virtual devices should always explicitly check which interrupt vector is mapped to a particular IRQ.

Uses

EAX, Flags