pSOSystem System Calls - Read

pSOS+ System Calls de_read
de_read Reads from an I/O device.
#include
unsigned long de_read(
unsigned long dev, /* major/minor device number */
void *iopb, /* I/O parameter block address */
void *retval /* return value */
)
Description
Arguments
Return Code
The de_read() call is used to read data from a device. It invokes the device read
routine of a pSOS+ device driver specified by the dev argument. This service
normally requires additional parameters contained in the I/O parameter block,
such as the address of a data area to hold the data and the number of data units to
read.
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. For example, it can hold the actual number of data units
read.
This call returns 0 on success, or an error code on failure. In addition to the error
codes listed below, other driver-specific errors may be returned.
pSOSystem System Calls 1-19
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