730 - Writing UnixWare 2.1 Device Drivers

Table of Contents

• Course Overview
• Course Objectives
• Prerequisites
• Course Series
• Course Topics

Course Overview

Writing UnixWare 2.1 Device Drivers is designed for:

• Experienced C programmers who would like to learn how to write a device driver.
• Programmers who already know how to write device drivers for another version of UNIX or any other multi-tasking operating system.

In this course, students learn the what device drivers are and how to write them for UnixWare's multi-user, multi-tasking, multi-processor enviroment.

Writing UnixWare 2.1 Device Drivers is taught with task-oriented lectures and hands-on labs. It is an high-level course that provides pre-requisite skill training for the Advanced UnixWare 2.1 Internals course.

Course Objectives

By the end of this course, students will be able to:

• Diagram the UnixWare architecture and explain the functionality of the major components of the kernel
• Describe basic features of the Intel 386 through Pentium II I/O hardware as it relates to device drivers
• Compare and contrast the various types of device drivers
• Explain the synchronization mechanisms used to protect sensative resources in a single and multi-processor system.
• Write, install, and use a interrupt and non-interrupt character device driver
• Create demand-loadable device drivers
• Create auto-configuring device drivers
• Create streams device drivers
• Create block-I/O device drivers
• Describe the architecture of SCSI and other storage technology device drivers in UnixWare 2.1

Prerequisites

Students should have at least 6 months of experience programming in C using system calls.

Course Series

This course is often taken as part of the following course sequence:

720 - Introduction to SCO UnixWare 2.1 Internals
730 - Writing Device Drivers
740 - Advanced SCO UnixWare 2.1 Internals

Course Topics

Overview of Device Drivers

• Overview of the Unix aernel architecture.
• The function of a device driver.
• Driver types:
• Character: open/close/read/write/ioctl.
• Stream: putqueue/getqueue.
• Block:
• Target: open/close/strategy/ioctl.
• HBAs: overview of concepts.
• Link types:
• Static.
• Dynamic.
• Review of the /etc/conf directory structure.

A Simple Character Driver

• The UnixWare DDI/DKI.
• Creating a simple Driver Software Package (DSP) for static drivers:
• The Master file.
• The System file.
• The Node file.
• The Drvmap file.
• The makefile file.
• The Driver.o file (and the cmn_err() routine).
• The id commands.
• The DSP for dynamic drivers.
• LAB: make the driver dynamic / test, no reboot, no restart
• Auto-configuring drivers
• Additional DSP files:
• The Autotune file.
• The Space.c file.
• Others breifly mentioned.

Intel-Specific Driver Issues

• I/O addresses and the in() and out() routines.
• Busy/Wait, polling, interrupts, and the spl() routines.
• Memory-Mapped I/O (i.e. dual-ported ram) and its associated routines.
• DMA and its associated routines.

A Basic (Character) Driver

• The load(), unload() and initialization routines.
• The open() routine.
• Moving data from/to the application:
• The read() routine.
• the write() routine.
• The close() routine.
• The ioctl() routine.
• The interrupt() routine, IPLs, and multi-threaded IPLs/locks
• Unreliable devices, timeouts, and associated routines.

Streams Drivers

• Where did streams come from?
• Overview of a streams driver (head, driver, queues, modules).
• A streams device's DSP.
• Streams device driver routines: getqueue(), putqueue(), etc.
• Streams flow-control.
• Overview of multiplexing streams drivers.

Block Drivers

• A block-device's DSP.
• The buffer cache.
• The strategy() routine.

The Host and Target Driver Scheme for Storage Devices

• What is an HBA driver?
• What is a Target driver?
• The relationship between HBA and Target drivers.
• The HBA initialization sequence and the claiming of Target devices.
• I/O sequences and their relationship to block (Target) drivers.

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