Strange.  sbus is a child of the root node.  There's no iommu node.

ok dev /
ok ls
f002d248 sbus
...
ok dev /sbus
ok .properties
ranges                   00000000 00000000 00000000 30000000 10000000 
                         00000001 00000000 00000000 40000000 10000000 
                         00000002 00000000 00000000 50000000 10000000 
                         00000003 00000000 00000000 60000000 10000000 
                         00000004 00000000 00000000 70000000 10000000 
#size-cells              00000001 
#address-cells           00000002 
name                     sbus


My understanding is that microSPARC-II MMU is used for both memory and
I/O.  At least STP-1012 manual says about MMU:

    It also serves as an I/O MMU and controls the arbitration between
    I/O, Data Cache, Instruction Cache, and TLB refer-ences to memory.

and later about Sbus:

    The SBus interface works with the MMU to arbitrate the system and
    memory resources and for I/O address translations.

Also microSPARC-IIep manual says that pa[30:28] == 001 address space
is "Control Space (Sun-4M system registers, 256 MByte)".


How shall I attach this thing???

SY, Uwe
-- 
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