Specifications

Operating System Routines
EXE$QIODRVPKT
When EXE$INSIOQ returns to EXE$QIODRVPKT at IPL$_ASTDEL,
EXE$QIODRVPKT returns control to the system service dispatcher in the
following steps:
1. Loads SS$_NORMAL into R0
2. Lowers IPL to zero
3. Issues the RET instruction that restores the original access mode of the
caller of the $QIO system service and returns control to the system service
dispatcher
The image that requested the I/O operation receives status SS$_NORMAL in R0,
indicating that the I/O request has completed without device-independent error.
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