Various Whitepapers

Jim Blakey




Overview of Radio Theory

This is a basic review of how signals are modulated on a carrier wave. I wrote this up as part of a training course I was creating for a client.

Discrete and Fast Fourier Transforms

FFTs and DFTs are probably the most important algorithm techniques in Digital Signal Processing. I had to do some work in this area for a client and most of the resources I found on the Internet approached the topic from a purely mathematical perspective. I decided to write this one up from a more useful engineering approach with some (hopefully) useful examples.

Slab Memory Management in the Linux 2.4 Kernel

A new Slab Cache memory management subsystem was introduced in the Linux 2.4 kernel to better optimize how drivers and kernel modules allocated and released memory pages for dynamic objects. This paper describes how this Slab manager works.

Ptrace

PTrace is one of the more useful tools in most Unix systems. This allows one process to "attach" to an already running child process, view the child's memory and register content, single step and break point the child and generally control the execution of the child. Ptrace is the foundation of how all Unix debuggers work. In this whitepaper, I give some examples on how to write quick, very targeted debuggers using Ptrace to debug specific problems in executables.