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Wolfgang Denk265817c2005-09-25 00:53:22 +02001By Thomas.Lange@corelatus.se 2004-Oct-05
2----------------------------------------
3DbAu1xx0 are development boards from AMD containing
4an Alchemy AU1xx0 series cpu with mips32 core.
5Existing cpu:s are Au1000, Au1100, Au1500 and Au1550
6
7Limitations & comments
8----------------------
9Support was originally big endian only.
10I have not tested, but several u-boot users report working
11configurations in little endian mode.
12
13I named the board dbau1x00, to allow
14support for all three development boards
15( dbau1000, dbau1100 and dbau1500 ).
16Now there is a new board called dbau1550 also, which
17should be supported RSN.
18
19I only have a dbau1000, so my testing is limited
20to this board.
21
22The board has two different flash banks, that can
23be selected via dip switch. This makes it possible
24to test new bootloaders without thrashing the YAMON
25boot loader delivered with board.
26
27NOTE! When you switch between the two boot flashes, the
28base addresses will be swapped.
29Have this in mind when you compile u-boot. TEXT_BASE has
30to match the address where u-boot is located when you
31actually launch.
32
33Ethernet only supported for mac0.
34
35PCMCIA only supported for slot 0, only 3.3V.
36
37PCMCIA IDE tested with Sandisk Compact Flash and
38IBM microdrive.
39
40###################################
41######## NOTE!!!!!! #########
42###################################
43If you partition a disk on another system (e.g. laptop),
44all bytes will be swapped on 16bit level when using
45PCMCIA and running cpu in big endian mode!!!!
46
47This is probably due to an error in Au1000 chip.
48
49Solution:
50
51a) Boot via network and partition disk directly from
52dbau1x00. The endian will then be correct.
53
54b) Partition disk on "laptop" and fill it with all files
55you need. Then write a simple program that endian swaps
56whole disk,
57
58Example:
59Original "laptop" byte order:
60B0 B1 B2 B3 B4 B5 B6 B7 B8 B9...
61
62Dbau1000 byte order will then be:
63B1 B0 B3 B2 B5 B4 B7 B6 B9 B8...