add a hack for Decap Attack
[picodrive.git] / svp.c
... / ...
CommitLineData
1// The SVP chip emulator
2
3// (c) Copyright 2008, Grazvydas "notaz" Ignotas
4// Free for non-commercial use.
5
6// For commercial use, separate licencing terms must be obtained.
7
8
9#include "../../PicoInt.h"
10
11svp_t *svp = NULL;
12int PicoSVPCycles = 1000; // cycles/line
13
14/* save state stuff */
15typedef enum {
16 CHUNK_IRAM = CHUNK_CARTHW,
17 CHUNK_DRAM,
18 CHUNK_SSP
19} chunk_name_e;
20
21static carthw_state_chunk svp_states[] =
22{
23 { CHUNK_IRAM, 0x800, NULL },
24 { CHUNK_DRAM, sizeof(svp->dram), NULL },
25 { CHUNK_SSP, sizeof(svp->ssp1601), NULL },
26 { 0, 0, NULL }
27};
28
29
30static void PicoSVPReset(void)
31{
32 elprintf(EL_SVP, "SVP reset");
33
34 memcpy(svp->iram_rom + 0x800, Pico.rom + 0x800, 0x20000 - 0x800);
35 ssp1601_reset(&svp->ssp1601);
36 if (!(PicoOpt&0x20000))
37 ssp1601_dyn_reset(&svp->ssp1601);
38}
39
40
41static void PicoSVPLine(int count)
42{
43 // ???
44 if (PicoOpt&0x20000)
45 ssp1601_run(PicoSVPCycles * count);
46 else
47 ssp1601_dyn_run(PicoSVPCycles * count);
48
49 // test mode
50 //if (Pico.m.frame_count == 13) PicoPad[0] |= 0xff;
51}
52
53
54static int PicoSVPDma(unsigned int source, int len, unsigned short **srcp, unsigned short **limitp)
55{
56 if (source < Pico.romsize) // Rom
57 {
58 source -= 2;
59 *srcp = (unsigned short *)(Pico.rom + (source&~1));
60 *limitp = (unsigned short *)(Pico.rom + Pico.romsize);
61 return 1;
62 }
63 else if ((source & 0xfe0000) == 0x300000)
64 {
65 elprintf(EL_VDPDMA|EL_SVP, "SVP DmaSlow from %06x, len=%i", source, len);
66 source &= 0x1fffe;
67 source -= 2;
68 *srcp = (unsigned short *)(svp->dram + source);
69 *limitp = (unsigned short *)(svp->dram + sizeof(svp->dram));
70 return 1;
71 }
72 else
73 elprintf(EL_VDPDMA|EL_SVP|EL_ANOMALY, "SVP FIXME unhandled DmaSlow from %06x, len=%i", source, len);
74
75 return 0;
76}
77
78
79void PicoSVPInit(void)
80{
81 void *tmp;
82
83 elprintf(EL_SVP, "SVP init");
84
85 tmp = realloc(Pico.rom, 0x200000 + sizeof(*svp));
86 if (tmp == NULL)
87 {
88 elprintf(EL_STATUS|EL_SVP, "OOM for SVP data");
89 return;
90 }
91
92 Pico.rom = tmp;
93 svp = (void *) ((char *)tmp + 0x200000);
94 memset(svp, 0, sizeof(*svp));
95
96 // init SVP compiler
97 if (!(PicoOpt&0x20000)) {
98 if (ssp1601_dyn_init()) return;
99 }
100
101 // init ok, setup hooks..
102 PicoRead16Hook = PicoSVPRead16;
103 PicoWrite8Hook = PicoSVPWrite8;
104 PicoWrite16Hook = PicoSVPWrite16;
105 PicoDmaHook = PicoSVPDma;
106 PicoResetHook = PicoSVPReset;
107 PicoLineHook = PicoSVPLine;
108
109 // save state stuff
110 svp_states[0].ptr = svp->iram_rom;
111 svp_states[1].ptr = svp->dram;
112 svp_states[2].ptr = &svp->ssp1601;
113 carthw_chunks = svp_states;
114}
115