Specifications

Operating System Routines
EXE$ALTQUEPKT
EXE$ALTQUEPKT
Delivers an IRP to a driver’s alternate start-I/O routine without regard for the
status of the device.
Module
SYSQIOREQ
Input
Location Contents
R3 Address of IRP
R5 Address of UCB
DDT$L_ALTSTART Address of alternate start-I/O routine
UCB$B_FLCK Fork lock index
UCB$L_DDB Address of unit’s DDB
DDB$L_DDT Address of DDT
Output
Location Contents
R0 through R5 Destroyed
Synchronization
A driver FDT routine calls EXE$ALTQUEPKT at IPL$_ASTDEL.
EXE$ALTQUEPKT raises to fork IPL (acquiring any required fork lock) before
calling the driver’s alternate start-I/O routine. When the alternate start-I/O
routine returns control to it, EXE$ALTQUEPKT returns control to its caller at
the caller’s IPL (having released its acquisition of the fork lock).
Description
EXE$ALTQUEPKT calls the driver’s alternate start-I/O routine. It does not test
whether the unit is busy before making the call.
3–18