root
 \-mainbus0
    |-cpu0
    |-iommu0
    |  \-sbus0
    |     |-bpp0
    |     |-cgsix0
    |     |  \-wsdisplay0
    |     |-dma0
    |     |  \-esp0
    |     |     \-scsibus0
    |     |        |-cd0
    |     |        |-sd0
    |     |        \-sd1
    |     |-ledma0
    |     |  \-le0
    |     \-qec0
    |        |-qe0
    |        |-qe1
    |        |-qe2
    |        \-qe3
    \-obio0
       |-auxreg0
       |-clock0
       |-fdc0
       |  \-fd0
       |-power0
       |-timer0
       |-zs0
       |  |-zstty0
       |  \-zstty1
       \-zs1
          |-zskbd0
          \-zstty2