Writing Device Drivers for the SCSI/CAM Architecture Interfaces

This document serves as a detailed guide for systems programmers developing device drivers for SCSI/CAM (Small Computer System Interface Common Access Method) architecture in the DEC OSF/1 operating system environment. It covers the following key areas:

• SCSI/CAM Architecture: Provides an overview of the layered software model, including the Transport (XPT) layer and SCSI Interface Module (SIM).
• User Agent Modules: Explains how user-process programs can communicate with the CAM subsystem and provides sample programs.
• Common and Generic Modules: Details the common data structures, routines, and macros available to device driver writers to ensure consistency with the CAM architecture.
• Configuration Driver: Describes the initialization process and equipment device table (EDT) management.
• Error Handling & Debugging: Discusses the error-logging macros, structures, and debugging facilities available to simplify driver development and maintenance.
• Programmer-Defined Drivers: Offers guidance and specific code examples on how to define and add custom device drivers, including tape and disk-specific structures.
• SCSI/CAM Special I/O Interface: Describes the interface for processing special SCSI I/O control commands.

The manual also includes detailed reference pages for routines and appendices detailing header files, command utilities (SCU), and sample driver source code.