Specifications

OpenVMS System Routines Called by OpenVMS AXP Device Drivers
IOC$ALLOCATE_CRAM
IOC$ALLOCATE_CRAM
Allocates a controller register access mailbox.
Module
CRAM-ALLOC
Macro
DPTAB (ucb_crams and idb_crams arguments) CRAM_ALLOC
Format
IOC$ALLOCATE_CRAM cram [,idb] [,ucb] [,adp]
Context
IOC$ALLOCATE_CRAM conforms to the OpenVMS AXP calling standard.
Because IOC$ALLOCATE_CRAM may need to allocate pages from the free page
list, its caller must be executing at or below IPL$_SYNCH and must not hold
spin locks ranked higher than IO_MISC.
IOC$ALLOCATE_CRAM acquires and releases the IO_MISC spin lock and
returns to its caller at its caller’s IPL.
Arguments
cram
VMS Usage: address
type: longword (unsigned)
access: write only
mechanism: by reference
Address of CRAM allocated by IOC$ALLOCATE_CRAM
idb
VMS Usage: address
type: longword (unsigned)
access: read only
mechanism: by reference
Address of IDB for device.
ucb
VMS Usage: address
type: longword (unsigned)
access: read only
mechanism: by reference
Address of UCB for device.
adp
VMS Usage: address
type: longword (unsigned)
access: read only
mechanism: by reference
A–10