What problem does it solve? Bringing up an OS or writing drivers for the Raspberry Pi 4 requires accurate knowledge of BCM2711 addresses, boot flow, interrupts, and peripheral quirks, but that information is scattered across datasheets, device trees, and GPL kernel source that cannot be copied into differently-licensed code. ## Core Features & Use Cases - Board-specific hardware map: Provides MMIO addresses, IRQ numbers, clock/power ownership, GPIO pull-register details, and boot-chain behavior for the BCM2711 (Pi 4B, Pi 400, CM4). - Clean-room subagent delegation: Runs as an isolated expert agent that reads GPL sources in a private cache and returns only hardware facts and mechanism descriptions, never source code. - Curated source cache: Clones and reuses the Raspberry Pi kernel tree, TF-A, firmware, and public datasheets under ~/src/rpi4-resources for grounded answers. - Use Case: While porting an OS to the Pi 4, ask where the debug UART lives and why the console is silent; the expert returns the PL011 address 0xFE20_1000, the mini-UART trap, and the disable-bt overlay fix without exposing any kernel code. ## Quick Start Ask the agent to spawn the rpi4-expert subagent and answer where the PL011 debug UART and GIC-400 registers are mapped on the BCM2711.
