Executable Formats

The number of different executable file types is as many and varied as the number of different image and sound file formats. Every Operating System seems to have several executable file types unique to itself. This part of the FAQ will give a brief rundown on the various types you will come across.

A quick intro to a few terms:

• TEXT is the actual executable code area,
• DATA is "initialized" data,
• BSS is "un-initialized" data.

The BSS (Below Stack Segment) needn't to be present in an executable file. At load-time, the loader will still allocate memory for it and wipes this memory with zeros (this is assumed by C programs, for instance).

If you're looking for comprehensive informations, consider using the Programmer's File Format Collection and the Linkers and Loaders online book... You can also check Pierre's Library