Devices & Drivers
How the kernel discovers hardware, binds drivers to it, and exposes the big device classes — buses, peripherals, and the frameworks that make them look uniform to user space.
- Drivers (drivers/) — the device model and how drivers bind to hardware (buses, PCI, device tree, platform, I2C/SPI)
- USB (usb/) — the host-scheduled, hot-pluggable peripheral bus: descriptors, endpoints, and URBs
- GPU / DRM (drm/) — the graphics and display stack: KMS modesetting, GEM buffers, and command submission
- Audio / ALSA (alsa/) — the sound subsystem: the card/PCM/control object model, the ring-buffer data path, and ASoC for embedded audio
- Input / HID (input/) — the input core, evdev, and the self-describing HID report-descriptor protocol
- TTY / Serial (tty/) — the teletypewriter-derived terminal model: line disciplines, serial core/UART drivers, and pseudo-terminals