anchor.diff:  
   (defpackage :mezzano.driver.intel-hda
     (:use :cl)
  -  (:local-nicknames (:pci :mezzano.supervisor.pci)))
  +  (:local-nicknames (:pci :mezzano.supervisor.pci)
  +                    (:sync :mezzano.sync)))
   
   (in-package :mezzano.driver.intel-hda)
   
  
positive.code:    (rirbsize :initarg :rirbsize :accessor hda-rirbsize)
     (rirb-read-pointer :initarg :rirb-read-pointer :accessor hda-rirb-read-pointer)
     (codecs :initarg :codecs :accessor hda-codecs)
     (interrupt-latch :initarg :interrupt-latch :accessor hda-interrupt-latch)
     (interrupt-handler :initarg :interrupt-handler :accessor hda-interrupt-handler)
     (dma-buffer-phys :initarg :dma-buffer-phys :accessor hda-dma-buffer-phys)
     (dma-buffer-virt :initarg :dma-buffer-virt :accessor hda-dma-buffer-virt)
     (dma-buffer-size :initarg :dma-buffer-size :accessor hda-dma-buffer-size))
  
negative.code:             (dotimes (i buf-len)
                (setf (mezzano.supervisor::physical-memref-unsigned-byte-8 buffer i) 0))
              ;; Unmask the interrupt, flush any pending IRQs.
              (clear-pending-interrupt hda output-stream)
              (mezzano.supervisor:simple-irq-unmask (hda-irq hda)))
            ;; Begin playback.
            (multiple-value-bind (converter mixer)
                (output-path output-pin)
  