Apple’s Darwin OS and XNU Kernel Deep Dive

This post is the result of me going down a several week long XNU rabbit-hole after reading this post by Thomas Claburn on Exclaves, more on that later. I’ve tried my best to condense all the information into a single blog post. I’ve also tried to keep sections self-contained so you can skip around using the table of contents, this does come at the cost of repeating myself in some places, so thanks in advance for your patience. While I’m confident of my understanding on this topic, some errors are inevitable when dealing with content this dense, if you spot any errors, assume them to be mine and please reach out so I can correct it, also let me know your thoughts by reaching out via email or mastodon. Thanks in advance and let’s begin! Introduction Apple’s Darwin operating system is the Unix-like core underpinning macOS, iOS, and all of Apple’s modern OS platforms. At its heart lies the XNU kernel – an acronym humorously standing for “X is Not Unix.” XNU is a unique hybrid kernel that ... Read full article.