Articles

How macOS keeps an Apple Silicon Mac running for 18 hours on a battery — cluster-level voltage scaling, idle gating, the pmgr driver, and the power-island architecture.

Same IOKit object model, userland process. Why kexts are dying, what DriverKit gives you, and how a USB driver actually crosses the boundary.

Inside dyld — Loader data structures, the modern chained-fixups format, PrebuiltLoaders in the shared cache, and what dlopen actually does at runtime.

Every system dylib pre-linked into one giant memory-mappable file, shared across every process on the system. Why a fresh process has 1 GB of virtual size but tiny resident memory.

The IOKit object that lets CPU, GPU, ANE, ISP, and media engines share the same physical pages. The unifying primitive behind unified memory's performance story.

The path from a kernel panic to a stack trace — the panic handler, the KDP wire protocol, attaching lldb to a panicked kernel, and what's recoverable on a live system.

Dispatch queues, the workqueue thread pool, voucher adoption, async vs sync — what happens between your dispatch_async call and your block running on a worker thread.

Six interlocking layers — code signing, AMFI, entitlements, sandbox profiles, SIP, TCC, and the SEP — that together decide what code is allowed to do on a Mac.

POSIX says signals are per-process. Mach says everything is a thread. Here's how XNU bridges the two — pending masks, delivery threads, the AST mechanism, and exception ports.