Here are some links to free books on the subject of embedded programming, I have not completed looking these over myself, but thought I would share for others to research as well.
Three FREE Books About Embedded Design
In my now more than two decades of work as a consultant and trainer in the field of embedded systems design, I have written three books and nearly one hundred articles. Almost all of this valuable information, including two of the books in their entirety, is available on the Barr Group website.
- "Embedded C Coding Standard": HTML (browsable), PDF (free), Paperback ($5.99)
- "Programming Embedded Systems in C and C++": HTML (browsable first edition)
- "Embedded Systems Dictionary": HTML (browsable subset)