Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 615

PAL_BUS_GET_FEATURES – Get Processor Bus Dependent
Configuration Features (9)
Provides information about configurable processor bus features.
Purpose:
Static Registers Only
Calling Conv:
Physical
Mode:
Not dependent
Buffer:
Arguments:
Argument
index
Reserved
Reserved
Reserved
Returns:
Return Value
status
features_avail
feature_status
feature_control
Status:
Status Value
0
-2
-3
Table 11-63
Description:
the return vector. Different busses will implement similar features in different ways. For
example, data error detection may be implemented by ECC or parity. In other cases,
certain features may be tied together. In this case, enabling any one feature in a group
will enable all features in the group, and similarly, disabling any one feature in a group
will disable all features. Caller algorithms should be written to obtain desired results in
these instances. Only those configuration features for which a 1 is returned in
feature_control can be changed via PAL_BUS_SET_FEATURES.
For all values in
be available (Req.) or is optional (Opt.). The Control field indicates which features are
required to be controllable. These features will either be controllable through this PAL
call or through other hardware means like forcing bus pins to a certain value during
processor reset. The control field applies only when the feature is available.
PALE_CHECK and PALE_INIT should not modify these features. An operating system
should not modify bus features without detailed information about the platform it is
running on.
Volume 2, Part 1: Processor Abstraction Layer
Description
Index of PAL_BUS_GET_FEATURES within the list of PAL procedures.
0
0
0
Description
Return status of the PAL_BUS_GET_FEATURES procedure.
64-bit vector of features implemented. See
implemented)
64-bit vector of current feature settings. See
64-bit vector of features controllable by software. (1=controllable, 0= not controllable)
Description
Call completed without error
Invalid argument
Call completed with error
defines the set of possible bus interface features and their bit position in
Table 11-63, the Class field indicates whether a feature is required to
PAL_BUS_GET_FEATURES
Table 11-63. (1=implemented, 0=not
Table 11-63.
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