Abstract

While browsing through the Linux kernel, I came upon a technique for creating a segment of function pointers which can be called at a later time in the order that they are inserted into the segment. The kernel uses this mechanism to call device driver initialization routines at boot-up.

I had a hard time finding clear information about what was going on and how it worked. After much googling (and some code doodling) I understand what is happening. This paper is an attempt at putting what I understand of this process down on paper so others may hopefully find it useful.

This technique depends on, and requires the use of, the GNU compiler and linker tools. Additionally, the ELF binary executable format must be used. This is not a general-puropse ANSI-C compliant technique.

Please direct any useful observations or comments to (remove spaces and adjust the formatting): twoerner.k AT gmail DOT com