XXexist(5) (RM400 only) XXexist(5)
NAME
XXexist - determine if a device exists
SYNOPSIS
#include <sys/infconfig.h>
int XXexist(intrparamt *);
DESCRIPTION
The XXexist routine is the first function called for a given driver.
Its function is to determine if the driver has any hardware to con-
trol. The information given in the intrparamt structure can be used
to differentiate between various pieces of hardware.
The intrparamt structure consists of the following definitions:
typedef struct intrparams {
int bustype;
int unit;
struct ioaddressinfo ioports[1];
int spare[12];
} intrparamt;
The members of this structure are:
bustype This specifies that the hardware is either on the EISA or
ISA bus.
unit This value is taken from the unit field of the sdevice
file. It can be used to determine which device is being
referenced.
ioports This structure is not currently used, but may in a later
revision of the Reliant UNIX system allow the driver to
determine which I/O ports on the ISA bus should be used.
The XXexist routine can return one of two values. If the hardware does
not exist, then the routine should return PROBEFAIL. If the hardware
exists or if the routine cannot determine if the hardware exists, then
the routine should return PROBEOK. PROBEOK and PROBEFAIL are both
defined in intconfig.h.
The XXexist routine is called before any interrupts are enabled, so
interrupts cannot be used. The XXexist routine cannot allocate memory.
FILES
sys/intconfig.h
Page 1 Reliant UNIX 5.44 Printed 11/98