How to learn about iPhone jailbroken programming? [closed]

Question

I'm interested in learning about what additional features and APIs an app has access to when an iPhone is jailbroken. Can someone provide me with some basic resources to learn about this? I would be most interested in:

• documentation on the private APIs
• filesystem layout
• app configuration, e.g. how did WinterBoard replace SpringBoard? Apps that replace the lockscreen?
• tools needed

Suggestions appreciated.

Answer 1

Very good question. I've personally spend quite a bit of time on trying to find documentation on the private APIs, and even though I'm pretty sure I've come across it some time ago, right now I can't really find it anymore. However, I do have some answers to your questions. Let me share what I have so far:

Filesystem layout

• An old, but still mostly true guide on filesystem layout.

"Replacing" apps

I think most of the "hijacking" of original iPhone apps is based on catching and re-implementing objective-c messages through posing and comparable techniques. A good guide on this is available here. I'm note entirely sure that this is the mechanism at work though.

Tools

• A toolchain for iphone dev is available on google code. See this guide for info on how to install it.
  
• See this guide for info on how to use the default apple Xcode environment for development on a jailbroken phone.

Answer 2

This is the best thing I'v found on the subject so far : Jailbroken Development : Starter Pack