The previous post described motherboards and the memory map in Intel computers to set the scene for the initial phases of boot. Booting is an involved, hacky, multi-stage affair – fun stuff. Here’s an outline of the process: An outline of the boot sequence Things start rolling when you press the power button on the computer (no! do tell!). Once the motherboard is powered up it initializes its own firmware – the chipset and other tidbits – and tries to get the CPU running. If things fail at this point (e.g., the CPU is busted or missing) then you will likely...

[The Python version described in this article is 3.x, more specifically - the 3.3 alpha release of CPython.]The concept of a callable is fundamental in Python. When thinking about what can be "called", the immediately obvious answer is functions. Whether it’s user defined functions (written by you), or builtin functions (most probably implemented in C inside the CPython interpreter), functions were meant to be called, right?Well, there are also methods, but they’re not very interesting because they’re just special functions that are bound to objects. What else can be call...

Welcome to the second part of the “PHP’s Source Code For PHP Developers” series.In the previous part ircmaxell explained where you can find the PHP source code and how it is basically structured and also gave a small introduction to C (as that’s the language PHP is written in). If you missed that post, you probably should read it before starting with this one.What we’ll cover in this article is locating the definitions of internal functions in the PHP codebase, as well as understanding them.How to find function definitionsFor a start, let’s try t...