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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 | // comm area map: |
7 | // 00-01: cmd |
8 | // 02-03: error |
9 | // 04-07: arg0/response |
10 | // 08-0b: arg1 |
11 | // 0c: last_irq_vec_master |
12 | // 0d: last_irq_vec_slave |
13 | // 0e: exception_index_master |
14 | // 0f: exception_index_slave |
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15 | static void do_cmd(u16 cmd, u16 r[6], u32 is_slave) |
16 | { |
17 | u32 *rl = (u32 *)r; |
18 | u32 a, d; |
19 | u16 v; |
20 | |
21 | switch (cmd) |
22 | { |
23 | case CMD_ECHO: |
24 | v = read16(&r[4/2]) ^ (is_slave << 15); |
25 | write16(&r[6/2], v); |
26 | break; |
27 | case CMD_READ_FRT: |
28 | v = read_frt(); |
29 | write16(&r[4/2], v); |
30 | break; |
31 | case CMD_READ8: |
32 | a = read32(&rl[4/4]); |
33 | d = read8(a); |
34 | write32(&rl[4/4], d); |
35 | break; |
36 | case CMD_READ16: |
37 | a = read32(&rl[4/4]); |
38 | d = read16(a); |
39 | write32(&rl[4/4], d); |
40 | break; |
41 | case CMD_READ32: |
42 | a = read32(&rl[4/4]); |
43 | d = read32(a); |
44 | write32(&rl[4/4], d); |
45 | break; |
46 | case CMD_WRITE8: |
47 | a = read32(&rl[4/4]); |
48 | d = read32(&rl[8/4]); |
49 | write8(a, d); |
50 | break; |
51 | case CMD_WRITE16: |
52 | a = read32(&rl[4/4]); |
53 | d = read32(&rl[8/4]); |
54 | write16(a, d); |
55 | break; |
56 | case CMD_WRITE32: |
57 | a = read32(&rl[4/4]); |
58 | d = read32(&rl[8/4]); |
59 | write32(a, d); |
60 | break; |
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61 | case CMD_GETGBR: |
62 | asm("stc gbr, %0" : "=r"(d)); |
63 | write32(&rl[4/4], d); |
64 | break; |
65 | case CMD_GETVBR: |
66 | asm("stc vbr, %0" : "=r"(d)); |
67 | write32(&rl[4/4], d); |
68 | break; |
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69 | default: |
70 | r[2/2]++; // error |
71 | mem_barrier(); |
72 | break; |
73 | } |
74 | } |
75 | |
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76 | void main_c(u32 is_slave) |
77 | { |
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78 | u16 *r = (u16 *)0x20004000; |
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79 | |
80 | for (;;) |
81 | { |
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82 | u16 cmd, cmdr; |
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83 | |
84 | mem_barrier(); |
85 | cmd = read16(&r[0x20/2]); |
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86 | mem_barrier(); |
87 | cmdr = read16(&r[0x20/2]); |
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88 | if (cmd == 0 |
89 | || cmd != cmdr // documented as "normal" case |
90 | || ((cmd & 0x8000) ^ (is_slave << 15)) |
91 | || cmd == 0x4d5f) { // 'M_' from BIOS |
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92 | spin(64); |
93 | continue; |
94 | } |
95 | cmd &= 0x7fff; |
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96 | do_cmd(cmd, &r[0x20/2], is_slave); |
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97 | write16(&r[0x20/2], 0); |
98 | } |
99 | } |
100 | |
101 | // vim:ts=4:sw=4:expandtab |