|
include vpicd.inc pushfd cli ; disable interrupts mov esi, OFFSET32 Callback ; points to callback procedure VxDcall VPICD_Call_When_Hw_Int popfd mov [Next_Callback], esi ; address of next callback in chain |
The VPICD_Call_When_Hw_Int service installs a callback procedure for hardware interrupts. The system calls the callback procedure whenever a hardware interrupt occurs.
The caller must disable interrupts before calling this service.
Callback
Points to the callback procedure. When the system calls the procedure, the EBX register contains the handle of the current virtual machine.
The ESI register contains the address of the next procedure in the callback chain.
Although any virtual device can use this service, the service is intended for use by the virtual DMA device to detect completion of DMA transfers. On systems with hardware devices that interrupt frequently, use of this service should be avoided. Installing a callback procedure to process every hardware interrupt can have a major impact on performance.
The callback procedure is responsible for chaining to the next handler in the interrupt chain. It also must preserve the EBX register for the next handler.
ESI, Flags