Book: FreeBSD Device Drivers

Before even reading it I knew that this book would be excellent. J. Kong proved that on his previous book and this is just another equally good example of his writing skills. So, here is my review…



Title: FreeBSD Device Drivers: A Guide for the Interpid
Author: Joseph Kong

Chapter 1: Building and Running Modules
This is an introduction to FreeBSD kernel modules with some additional information on character and block devices kernel modules.

Chapter 2: Allocating Memory
After going through the memory management routines, he provides a simple and understandable example of using them in kernel modules.

Chapter 3: Device Communication and Control
Moving to this chapter we have the I/O operations starting with IOCTL and next discussing (always in detail) the SYSCTL interface and of course providing examples for both cases.

Chapter 4: Thread Synchronization
A very interesting chapter dealing with synchronization issues of concurrent threads. After analysing a race condition in a kernel module, J. Kong dives into the details of race condition prevention using MUTEXes, shared/exclusive locks, reader/writer locks and condition variables always along with straightforward examples of each subject.

Chapter 5: Delaying Execution
Basically this is all about sleeping and context switching using the numerous available ways that FreeBSD supports.

Chapter 6: Case Study: Virtual NULL Modem
As you can guess from the title, this is a case study of a working virtual NULL modem terminal driver.

Chapter 7: Newbus and Resource Allocation
This is the first chapter dealing with actual hardware interaction kernel programming using Newbus.

Chapter 8: Interrupt Handling
From registering an interrupt handler up to writing a complete interrupt handler and generating interrupts, Joseph Kong explains all the steps required to achieve this.

Chapter 9: Case Study: Parallel Port Printer Driver
This is the second case study in this book utilizing all of the previously discussed features.

Chapter 10: Managing and Using Resources
Another very informative chapter dealing with concepts such as I/O ports, I/O memory, stream operations and memory barriers.

Chapter 11: Case Study: Intelligent Platform Management Interface Driver
A complete case study of an IPMI device driver.

Chapter 12: Direct Memory Access
As you can easily deduce from the title here you can find information for DMA programming in FreeBSD kernel. Everything such as DMA tags, synchronizing DMA buffers, etc. along with example kernel modules are available in this chapter.

Chapter 13: Storage Drivers
Starting with the disk structure it moves to all the components required to write a working block I/O device driver.

Chapter 14: Common Access Method
This chapter goes through the details of CAM mainly for HBA and SIM drivers.

Chapter 15: USB Drivers
Continuing from the previous chapter that dealt with HBAs, this one moves to USB. After a brief overview of the architecture and the structures used in FreeBSD operating system, the author discusses the routines used for USB device driver development.

Chapter 16: Network Drivers, Part 1: Data Structures
The title is pretty much self explanatory. J. Kong explains the essential network interface structures for management, media, mbuf, etc. and he also provides a simple example to demonstrate them.

Chapter 17: Network Drivers, Part 2: Packet Reception and Transmission
This is a small chapter which is also the last one and it deals with the network reception and transmission routines of the FreeBSD kernel.

Once again, Joseph Kong wrote a book that is compact, concise and well written. Each chapter can be used alone as a reference but there is also a flow between them if you choose to read the entire book. I would suggest this book to anyone interested in FreeBSD device drivers development and have a basic understanding of operating systems and C programming. Additionally, if you are a security oriented programmer you can use it as inspiration for rootkit development. Definitely an excellent book with all the information you’ll need to start developing your own FreeBSD device drivers.