NAME

passthru − The SCSI ioctl command interface

DESCRIPTION

The SCSI passthrough interface provides the low-level ioctl system call facility to the Adaptec AHA1540 SCSI driver. 

The interface uses the existing HPDD ioctl() system call logic, therefore, it does not require a new version of the HPDD.  It is a version-dependent SCSI device driver. 

The interface is implemented by using the V_USRCMD ioctl() system call.  The interface depends on the common SCSI user interface structure, "scsiusr".  A new header file, /usr/include/sys/scsusr.h, was added to accommodate the newly added structures and defines.  The applications must allocate and initialize the "scsiusr" structure in user memory space and provide the kernel with a pointer to the address of the buffer allocated for this structure.  The pointer to this structure is passed to the kernel space as the ’arg’ argument of the ioctl() system call.  Each individual SCSI device driver validates the pointer passed by the user program and assumes the passed argument to be a value of the pointer to the "scsiusr" structure. 

DIAGNOSTICS

Returned error codes and their meanings:

EPERM
Not a super user; permission denied.

ENXIO
Wrong device name or non-existent device name.

EBUSY
Ioctl interface currently in use; try again.

EFAULT
Error when copyin() user buffer or the host bus adapter rejected the command.

EINVAL
Invalid combination of requests.  It could also mean invalid data length field, invalid data pointer field, invalid sense length field, or unimplemented SCSI ioctl request. 

EACCES
Extended read and write commands are not allowed.

SEE ALSO

aha1540(7). 

ADDED VALUE

This entry, supplied by SunSoft, Inc., is an extension of UNIX System V. 

\*U  —  Version 1.0