include vdmad.inc mov eax, DMA_Handle mov ebx, VMHandle VxDcall VDMAD_Get_Virt_State
Allows a channel owner to determine the current virtual state of the channel. Uses ECX, EDX, ESI, flags
If translation is not enabled, the ESI register contains the physical byte address programmed (shifted left 1, for word ports).
The ECX register contains count in bytes.
The DL register contains the mode. This is the same as the 8237 mode byte with channel number removed and the following DMA_masked and DMA_requested values set as appropriate:
DMA_masked | Channel masked and not ready for a transfer. |
DMA_requested | Software request flag set. |
The DH register contains the extended mode (ignored on non-PS/2 machines that do not have extended DMA capabilities).
DMA_Handle
Handle of DMA.
VMHandle
Handle of VM.
The virtual state consists of all the information necessary to physically program the DMA channel for a DMA transfer (linear address of target region, byte length of region, mode of transfer, and state of mask bit and software request bit).