Specifications

System Macros Invoked by Drivers

FUNCTAB

Example

XX_FUNCTABLE: ;Function decision table

FUNCTAB ,- ;Valid functions

<READLBLK,- ;Read logical block

READPBLK,- ;Read physical block

READVBLK,- ;Read virtual block

SENSEMODE,- ;Sense reader mode

SENSECHAR,- ;Sense reader characteristics

SETMODE,- ;Set reader mode

SETCHAR,- ;Set reader characteristics

FUNCTAB ,- ;Buffered-I/O functions

<READLBLK,- ;Read logical block

READPBLK,- ;Read physical block

READVBLK,- ;Read virtual block

SENSEMODE,- ;Sense reader mode

SENSECHAR,- ;Sense reader characteristics

SETMODE,- ;Set reader mode

SETCHAR,- ;Set reader characteristics

FUNCTAB XX_READ,- ;Read function FDT routine

<READLBLK,- ;Read logical block

READPBLK,- ;Read physical block

READVBLK,- ;Read virtual block

FUNCTAB +EXE$SETMODE,- ;Set mode/characteristics FDT routine

<SETCHAR,- ;Set reader characteristics

SETMODE,- ;Set reader mode

FUNCTAB +EXE$SENSEMODE,- ;Sense mode/characteristics FDT routine

<SENSECHAR,- ;Sense reader characteristics

SENSEMODE,- ;Sense reader mode

This function decision table speciﬁes that the routine XX_READ be called for

all read functions that are valid for the device. XX_READ appears later in the

driver module. System I/O preprocessing will call routines EXE$SETMODE and

EXE$SENSEMODE for the device’s set-characteristics and sense-mode functions.

Because each of these routines is part of the operating system, a plus sign (+)

precedes its name in the FUNCTAB macro argument.

2–38