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comparison m68k_util.c @ 1983:a7b753e260a2 mame_interp

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Merge from default
author Michael Pavone <pavone@retrodev.com>
date Sat, 09 May 2020 23:39:44 -0700
parents 8494fe8d6b65
children 414eb8c34198
comparison
equal deleted inserted replaced
1937:cafde1255ad3 1983:a7b753e260a2
1 #include <string.h>
2
3 void m68k_read_8(m68k_context *context)
4 {
5 context->cycles += 4 * context->opts->gen.clock_divider;
6 context->scratch1 = read_byte(context->scratch1, context->mem_pointers, &context->opts->gen, context);
7 }
8
9 void m68k_read_16(m68k_context *context)
10 {
11 context->cycles += 4 * context->opts->gen.clock_divider;
12 context->scratch1 = read_word(context->scratch1, context->mem_pointers, &context->opts->gen, context);
13 }
14
15 void m68k_write_8(m68k_context *context)
16 {
17 context->cycles += 4 * context->opts->gen.clock_divider;
18 write_byte(context->scratch2, context->scratch1, context->mem_pointers, &context->opts->gen, context);
19 }
20
21 void m68k_write_16(m68k_context *context)
22 {
23 context->cycles += 4 * context->opts->gen.clock_divider;
24 write_word(context->scratch2, context->scratch1, context->mem_pointers, &context->opts->gen, context);
25 }
26
27 void m68k_sync_cycle(m68k_context *context, uint32_t target_cycle)
28 {
29 //TODO: interrupt stuff
30 context->sync_cycle = target_cycle;
31 }
32
33 void init_m68k_opts(m68k_options *opts, memmap_chunk * memmap, uint32_t num_chunks, uint32_t clock_divider)
34 {
35 memset(opts, 0, sizeof(*opts));
36 opts->gen.memmap = memmap;
37 opts->gen.memmap_chunks = num_chunks;
38 opts->gen.address_mask = 0xFFFFFF;
39 opts->gen.byte_swap = 1;
40 opts->gen.max_address = 0x1000000;
41 opts->gen.bus_cycles = 4;
42 opts->gen.clock_divider = clock_divider;
43 }
44
45 m68k_context *init_68k_context(m68k_options * opts, m68k_reset_handler reset_handler)
46 {
47 m68k_context *context = calloc(1, sizeof(m68k_context));
48 context->opts = opts;
49 context->reset_handler = reset_handler;
50 context->int_cycle = 0xFFFFFFFFU;
51 return context;
52 }
53
54 void m68k_reset(m68k_context *context)
55 {
56 //read initial SP
57 context->scratch1 = 0;
58 m68k_read_16(context);
59 context->aregs[7] = context->scratch1 << 16;
60 context->scratch1 = 2;
61 m68k_read_16(context);
62 context->aregs[7] |= context->scratch1;
63
64 //read initial PC
65 context->scratch1 = 4;
66 m68k_read_16(context);
67 context->pc = context->scratch1 << 16;
68 context->scratch1 = 6;
69 m68k_read_16(context);
70 context->pc |= context->scratch1;
71
72 context->scratch1 = context->pc;
73 m68k_read_16(context);
74 context->prefetch = context->scratch1;
75 context->pc += 2;
76
77 context->status = 0x27;
78 }
79
80 void m68k_print_regs(m68k_context *context)
81 {
82 printf("XNZVC\n%d%d%d%d%d\n", context->xflag != 0, context->nflag != 0, context->zflag != 0, context->vflag != 0, context->cflag != 0);
83 for (int i = 0; i < 8; i++) {
84 printf("d%d: %X\n", i, context->dregs[i]);
85 }
86 for (int i = 0; i < 8; i++) {
87 printf("a%d: %X\n", i, context->aregs[i]);
88 }
89 }