diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/voyager.txt |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
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1 | Running Linux on the Voyager Architecture | ||
2 | ========================================= | ||
3 | |||
4 | For full details and current project status, see | ||
5 | |||
6 | http://www.hansenpartnership.com/voyager | ||
7 | |||
8 | The voyager architecture was designed by NCR in the mid 80s to be a | ||
9 | fully SMP capable RAS computing architecture built around intel's 486 | ||
10 | chip set. The voyager came in three levels of architectural | ||
11 | sophistication: 3,4 and 5 --- 1 and 2 never made it out of prototype. | ||
12 | The linux patches support only the Level 5 voyager architecture (any | ||
13 | machine class 3435 and above). | ||
14 | |||
15 | The Voyager Architecture | ||
16 | ------------------------ | ||
17 | |||
18 | Voyager machines consist of a Baseboard with a 386 diagnostic | ||
19 | processor, a Power Supply Interface (PSI) a Primary and possibly | ||
20 | Secondary Microchannel bus and between 2 and 20 voyager slots. The | ||
21 | voyager slots can be populated with memory and cpu cards (up to 4GB | ||
22 | memory and from 1 486 to 32 Pentium Pro processors). Internally, the | ||
23 | voyager has a dual arbitrated system bus and a configuration and test | ||
24 | bus (CAT). The voyager bus speed is 40MHz. Therefore (since all | ||
25 | voyager cards are dual ported for each system bus) the maximum | ||
26 | transfer rate is 320Mb/s but only if you have your slot configuration | ||
27 | tuned (only memory cards can communicate with both busses at once, CPU | ||
28 | cards utilise them one at a time). | ||
29 | |||
30 | Voyager SMP | ||
31 | ----------- | ||
32 | |||
33 | Since voyager was the first intel based SMP system, it is slightly | ||
34 | more primitive than the Intel IO-APIC approach to SMP. Voyager allows | ||
35 | arbitrary interrupt routing (including processor affinity routing) of | ||
36 | all 16 PC type interrupts. However it does this by using a modified | ||
37 | 5259 master/slave chip set instead of an APIC bus. Additionally, | ||
38 | voyager supports Cross Processor Interrupts (CPI) equivalent to the | ||
39 | APIC IPIs. There are two routed voyager interrupt lines provided to | ||
40 | each slot. | ||
41 | |||
42 | Processor Cards | ||
43 | --------------- | ||
44 | |||
45 | These come in single, dyadic and quad configurations (the quads are | ||
46 | problematic--see later). The maximum configuration is 8 quad cards | ||
47 | for 32 way SMP. | ||
48 | |||
49 | Quad Processors | ||
50 | --------------- | ||
51 | |||
52 | Because voyager only supplies two interrupt lines to each Processor | ||
53 | card, the Quad processors have to be configured (and Bootstrapped) in | ||
54 | as a pair of Master/Slave processors. | ||
55 | |||
56 | In fact, most Quad cards only accept one VIC interrupt line, so they | ||
57 | have one interrupt handling processor (called the VIC extended | ||
58 | processor) and three non-interrupt handling processors. | ||
59 | |||
60 | Current Status | ||
61 | -------------- | ||
62 | |||
63 | The System will boot on Mono, Dyad and Quad cards. There was | ||
64 | originally a Quad boot problem which has been fixed by proper gdt | ||
65 | alignment in the initial boot loader. If you still cannot get your | ||
66 | voyager system to boot, email me at: | ||
67 | |||
68 | <J.E.J.Bottomley@HansenPartnership.com> | ||
69 | |||
70 | |||
71 | The Quad cards now support using the separate Quad CPI vectors instead | ||
72 | of going through the VIC mailbox system. | ||
73 | |||
74 | The Level 4 architecture (3430 and 3360 Machines) should also work | ||
75 | fine. | ||
76 | |||
77 | Dump Switch | ||
78 | ----------- | ||
79 | |||
80 | The voyager dump switch sends out a broadcast NMI which the voyager | ||
81 | code intercepts and does a task dump. | ||
82 | |||
83 | Power Switch | ||
84 | ------------ | ||
85 | |||
86 | The front panel power switch is intercepted by the kernel and should | ||
87 | cause a system shutdown and power off. | ||
88 | |||
89 | A Note About Mixed CPU Systems | ||
90 | ------------------------------ | ||
91 | |||
92 | Linux isn't designed to handle mixed CPU systems very well. In order | ||
93 | to get everything going you *must* make sure that your lowest | ||
94 | capability CPU is used for booting. Also, mixing CPU classes | ||
95 | (e.g. 486 and 586) is really not going to work very well at all. | ||