Specifications

D
evice Driver Programming
Glossary-10
small computer system interface (SCSI)
The American National Standards Institute (ANSI) approved interface for supporting spe-
cific peripheral devices.
special device file
The file that identifies the device's access type (block or character), the external major and
minor numbers of the device, the device name used by user-level programs, and security
control (owner, group, and access permissions) for the device.
stream end
The stream end is the component of a stream farthest from the user process, providing the
interface to the device. It contains pointers to driver (rather than module) routines.
stream head
Every stream has a stream head, which is inserted by the STREAMS subsystem. It is the
component of a stream closest to the user process. The stream head processes
STREAMS-related system calls and performs the transfer of data between user and kernel
space.
STREAMS
A kernel subsystem used to build a stream, which is a modular, full-duplex data path
between a device and a user process.
stream
A linked list of kernel data structures providing a full-duplex data path between a user pro-
cess and a device or pseudo-device.
switch table entry points
Driver routines that are activated through bdevsw or cdevsw tables.
switch table
The operating system maintains switch tables for devices and STREAMS modules. These
tables hold pointers to entry point routines for character and block drivers and are acti-
vated by I/O system calls.
system initialization
The routines from the driver code and the information from the configuration files that ini-
tialize the system (including device drivers).
TCP
Transmission Control Protocol, a connection oriented transport in the Internet suite