Pico/carthw/svp/svp.c

   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
  11 svp_t *svp = NULL;
  12 int PicoSVPCycles = 1000; // cycles/line
  13
  14 /* save state stuff */
  15 typedef enum {
  16         CHUNK_IRAM = CHUNK_CARTHW,
  17         CHUNK_DRAM,
  18         CHUNK_SSP
  19 } chunk_name_e;
  20
  21 static 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
  30 static 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
  41 static 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
  54 static 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
  79 void 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