boards/BRINGUP.md A1, FABRIC-3 SXLII. xhci.c keeps a table of controllers
(up to 8) and services each; kernel_main brings up index 0, 1, ... until
there is none. repl.c's and blkio_usb.c's per-slot state is per
controller now (a slot ID is a controller's own), and each USB keyboard
keeps its own last report and lights; an unplugged keyboard releases what
it held.
Test first: keyboard and identity on a second controller behind a bridge,
Zuse on the first -- before, only Zuse; after, all three, on all three
ISAs. Hot-plug and unplug on the second controller. Acceptance unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>