Specifications

System Macros Invoked by Drivers
DPT_STORE
[pos]
Starting bit position within the specified field; used only if oper=V.
[size]
Number of bits to be written; used only if oper=V.
Description
The DPT_STORE macro places information in the DPT that the driver-loading
procedure uses to load specified values into specified fields. The DPT_STORE
macro accepts two lists of fields:
• Fields to be initialized only when a driver is first loaded
• Fields to be initialized when a driver is first loaded and reinitialized if the
driver is reloaded
The DPTAB macro stores the relative addresses of these two lists, called
initialization and reinitialization tables, in the DPT. A driver constructs the
initialization tables by following the DPTAB macro with one or more invocations
of the DPT_STORE macro.
Drivers use the DPT_STORE macro with the INIT table marker label to begin a
list of DPT_STORE invocations that supply initialization data for the following
fields:
UCB$B_FLCK Index of the fork lock under which the driver
performs fork processing. Fork lock indexes are
defined by the $SPLCODDEF definition macro
(invoked by DPTAB) as follows:
IPL Fork Lock Index
8 SPL$C_IOLOCK8
9 SPL$C_IOLOCK9
10 SPL$C_IOLOCK10
11 SPL$C_IOLOCK11
UCB$B_DIPL Device interrupt priority level.
Other commonly initialized fields are as follows:
UCB$L_DEVCHAR Device characteristics.
UCB$B_DEVCLASS Device class.
UCB$B_DEVTYPE Device type.
UCB$W_DEVBUFSIZ Default buffer size.
UCB$Q_DEVDEPEND Device-dependent parameters.
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