Questions on how to create/update Metazoa patches, ARM assembler, objdump, etc.

In this thread I will try to pass on what I have learned about making patches for the Kobo e-ink ereaders. I have been meaning to do this for a while now, but I never know where to start, so if you have a specific question just ask and I'll try to answer here.

I am not an expert on any of this, so don't assume the way I do something is the only way or the best way. I have a bit of background programming in C and x86 assembly language for Linux, but I didn't know anything about ARM CPUs or modifying programs without access to source code until I started patching my Glo. I've just learned the bits I needed as I went along, there are big gaps in my knowledge.

I use the following programs in Debian 8 Linux, there are alternatives for other systems but I haven't used them, so any explanation I give will be based on these:

* Disassembler: objdump (binutils-multiarch package)
* Hex editor: emacs [M-x hexl-open-file] (emacs24 package)
* Patcher: patch32lsb (included in tools/ directory of patch archives)
* A hexdecimal calculator can be handy, I have an old HP 42s.

I'll keep an index of topics in this first post and update it as different topics come up:

Post #2 Address vs. file offset
Post #3 Finding function addresses
Post #4 Patching compressed CSS strings