The tuple_t structure is the basic data structure
provided by card services to manage PC
card information. A PC card provides identification
and configuration information through its card information structure (CIS). A PC card driver accesses
a PC card's CIS through various card services functions.
The CIS information allows PC cards to be self-identifying: the CIS provides information to the system so that it can identify
the proper PC card driver for the PC card, and provides configuration information
so that the driver can allocate appropriate resources to configure the PC card for proper operation in the system.
The CIS information is contained
on the PC card in a linked list of tuple
data structures called a CIS chain. Each
tuple has a one-byte type and a one-byte link, an offset to the next tuple
in the list. A PC card can have one or
more CIS chains.
A multi-function PC card that complies
with the PC Card 95 MultiFunction Metaformat
specification will have one or more global CIS
chains that collectively are referred to as the global CIS.
These PC Cards will also have one or more
per-function CIS chains. Each per-function
collection of CIS chains is referred to
as a function-specific CIS.
To examine a PC card's CIS, first a PC card driver must
locate the desired tuple by calling csx_GetFirstTuple(9F). Once the first tuple is located, subsequent tuples
may be located by calling csx_GetNextTuple(9F). See csx_GetFirstTuple(9F). The linked list of tuples may be inspected one
by one, or the driver may narrow the search by requesting only tuples of
a particular type.
Once a tuple has been located, the PC
card driver may inspect the tuple data. The most convenient way to do this
for standard tuples is by calling one of the number of tuple-parsing utility
functions; for custom tuples, the driver may get access to the raw tuple
data by calling csx_GetTupleData(9F).
Solaris PC card drivers do not need
to be concerned with which CIS chain a
tuple appears in. On a multi-function PC
card, the client will get the tuples from the global CIS followed by the tuples in the function-specific CIS. The caller will not get any tuples from a function-specific CIS that does not belong to the caller's function.