Generating executable files from scratch

Introduction

The first step in getting the operating system to execute arbitrary assembly is to figure out what types of executable files your operating system supports. Since I would be developing my compiler on Linux, the suitable Executable and Linkable Format (ELF) was chosen. There is a veritable wealth of information on the composition of ELF files, however since the ELF standard is very large and overarching it is not a simple matter to be able to pick and choose what is needed to get a bare minimum example working. As such, I am writing this as a compendium of all the research and piecing together that I did to be able to write YABFC.

List of resources

• http://www.skyfree.org/linux/references/ELF_Format.pdf - ELF file format specification
• https://github.com/corkami/pics/blob/master/binary/elf101/elf101-64.pdf - Visualization of how an ELF file goes together
• http://nullprogram.com/blog/2016/11/17/ - "A Magnetized Needle and a Steady Hand", making an ELF file with echo commands
• https://defuse.ca/online-x86-assembler.htm - x86 intel-style instruction assembler