mov edi, offset32 IOP ; address of IOP
mov ebx, offset32 DCB ; address of logical or physical DCB
mov edx, vector ; address of a calldown request routine
; or zero
call [ilb.ILB_internal_request]
Passes the given I/O request to a driver in the calldown chain. A device driver uses this routine to send I/O requests though the calldown chain without calling the IOS_SendCommand service. The driver can either send the I/O request to the driver at the next layer in the chain or to the top of the chain.
ILB