I've recently had another need to fix an issue in frida and I had to re-discover some things about how to develop for this tool. With that in mind, this blog post is meant to cover some quick tips for how to go about developing or fixing frida's code base. Mostly so I can reference it later once I forget how it works again...

What is frida?

Frida is a dynamic binary instrumentation (DBI) tool, brought to life by Ole André Vadla Ravnås. At it's core, frida utilizes javascript to do much of the heavy lifting. There are actually two separate javascript engines that can be used, namely v8 and duk. This becomes important for development as the two engines can behave a bit differently. Also, they have separate (as well as shared) code bases in the framework. This means that developing for one engine does not automatically mean that the code you created (or debugged) will be available to the other engine.