Chapter 9. Upper level drivers

Table of Contents
9.1. Disk driver (sd)
9.1.1. sd boot parameters
9.1.2. sd module parameters
9.2. CDROM driver (sr or scd)
9.2.1. sr boot parameters
9.2.2. sr module parameters
9.2.3. sr proc interface
9.3. Tape driver (st)
9.3.1. st boot parameters
9.3.2. st module parameters
9.3.3. st proc interface
9.4. Generic driver (sg)
9.4.1. sg boot parameters
9.4.2. sg module parameters
9.4.3. sg proc interface

The upper level drivers maintain the kernel side of the OS interface for the logical class of devices they represent (e.g. disks). They are also responsible for managing certain kernel and SCSI subsystem resources such as kernel memory and SCSI command structures. Applications in the user space access these drivers by opening a special file (block or char) typically found in the /dev directory tree.