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1 | #include "common.h" |
2 | |
3 | void spin(int loops); |
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4 | u16 read_frt(void); |
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5 | |
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6 | static void do_cmd(u16 cmd, u16 r[6], u32 is_slave) |
7 | { |
8 | u32 *rl = (u32 *)r; |
9 | u32 a, d; |
10 | u16 v; |
11 | |
12 | switch (cmd) |
13 | { |
14 | case CMD_ECHO: |
15 | v = read16(&r[4/2]) ^ (is_slave << 15); |
16 | write16(&r[6/2], v); |
17 | break; |
18 | case CMD_READ_FRT: |
19 | v = read_frt(); |
20 | write16(&r[4/2], v); |
21 | break; |
22 | case CMD_READ8: |
23 | a = read32(&rl[4/4]); |
24 | d = read8(a); |
25 | write32(&rl[4/4], d); |
26 | break; |
27 | case CMD_READ16: |
28 | a = read32(&rl[4/4]); |
29 | d = read16(a); |
30 | write32(&rl[4/4], d); |
31 | break; |
32 | case CMD_READ32: |
33 | a = read32(&rl[4/4]); |
34 | d = read32(a); |
35 | write32(&rl[4/4], d); |
36 | break; |
37 | case CMD_WRITE8: |
38 | a = read32(&rl[4/4]); |
39 | d = read32(&rl[8/4]); |
40 | write8(a, d); |
41 | break; |
42 | case CMD_WRITE16: |
43 | a = read32(&rl[4/4]); |
44 | d = read32(&rl[8/4]); |
45 | write16(a, d); |
46 | break; |
47 | case CMD_WRITE32: |
48 | a = read32(&rl[4/4]); |
49 | d = read32(&rl[8/4]); |
50 | write32(a, d); |
51 | break; |
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52 | case CMD_GETGBR: |
53 | asm("stc gbr, %0" : "=r"(d)); |
54 | write32(&rl[4/4], d); |
55 | break; |
56 | case CMD_GETVBR: |
57 | asm("stc vbr, %0" : "=r"(d)); |
58 | write32(&rl[4/4], d); |
59 | break; |
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60 | default: |
61 | r[2/2]++; // error |
62 | mem_barrier(); |
63 | break; |
64 | } |
65 | } |
66 | |
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67 | void main_c(u32 is_slave) |
68 | { |
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69 | u16 *r = (u16 *)0x20004000; |
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70 | |
71 | for (;;) |
72 | { |
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73 | u16 cmd, cmdr; |
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74 | |
75 | mem_barrier(); |
76 | cmd = read16(&r[0x20/2]); |
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77 | mem_barrier(); |
78 | cmdr = read16(&r[0x20/2]); |
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79 | if (cmd == 0 |
80 | || cmd != cmdr // documented as "normal" case |
81 | || ((cmd & 0x8000) ^ (is_slave << 15)) |
82 | || cmd == 0x4d5f) { // 'M_' from BIOS |
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83 | spin(64); |
84 | continue; |
85 | } |
86 | cmd &= 0x7fff; |
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87 | do_cmd(cmd, &r[0x20/2], is_slave); |
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88 | write16(&r[0x20/2], 0); |
89 | } |
90 | } |
91 | |
92 | // vim:ts=4:sw=4:expandtab |