pSOSystem System Calls - Read

pSOS+ System Calls de_cntrl
de_cntrl Requests a special I/O device service.
#include
unsigned long de_cntrl(
unsigned long dev, /* major/minor device number */
void *iopb, /* I/O parameter block address */
void *retval /* return value */
)
Description
Arguments
Return Code
The de_cntrl() call invokes the device control routine of a pSOS+ device driver
specified by the dev argument. The functionality of a device control routine depends
entirely on the device driver implementation. It can include anything that cannot be
categorized under the other five I/O services. de_cntrl() for a device can be used
to perform multiple input and output subfunctions. In such cases, extra parameters
in the I/O parameter block can designate the subfunction.
dev Specifies the major and minor device numbers, which are stored in
the upper and lower 16 bits, respectively.
iopb Points to an I/O parameter block, the contents of which are driverspecific.
retval Points to a variable that receives a driver-specific value returned by
the driver.
This call returns 0 on success or an error code on failure. Beside the error codes
listed below, other driver-specific errors may be returned.
pSOSystem System Calls 1-13
1