Subject: Sbus in JS1
To: None <port-sparc@netbsd.org>
From: Valeriy E. Ushakov <uwe@ptc.spbu.ru>
List: port-sparc
Date: 04/20/2001 07:23:47
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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