Drivers
Phase 5 of the driver-development path — 0/48 bytes, gated behind Phases 2–4
Character Device Drivers
Not yet catalogued — waiting on Phases 2–4 to unlock this phase. The centerpiece topic: "walk me through writing a char driver" is the single most-asked driver interview question. 16 bytes across 2 chapters.
Platform Drivers and Device Tree
Not yet catalogued — how non-discoverable hardware gets described to the kernel, and how a driver gets matched to it. 9 bytes.
GPIO & Simple Hardware
Not yet catalogued — the descriptor-based GPIO API, and the first place interrupts meet a driver in this phase. 5 bytes.
I2C and SPI Drivers
Not yet catalogued — moving from the protocol theory in 3.6 to actual kernel client drivers for both buses. 10 bytes across 2 chapters.
Driver Quality & Advanced Concepts
Not yet catalogued — the discipline that separates a driver that works from one that's actually production-quality: correct locking, clean error paths, and managed resources. 8 bytes.