| 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 = 800; // cycles/line |
| 13 | |
| 14 | static void PicoSVPReset(void) |
| 15 | { |
| 16 | elprintf(EL_SVP, "SVP reset"); |
| 17 | |
| 18 | memcpy(svp->iram_rom + 0x800, Pico.rom + 0x800, 0x20000 - 0x800); |
| 19 | ssp1601_reset(&svp->ssp1601); |
| 20 | } |
| 21 | |
| 22 | |
| 23 | static void PicoSVPLine(int count) |
| 24 | { |
| 25 | // ??? |
| 26 | // OSC_NTSC / 3.0 / 60.0 / 262.0 ~= 1139 |
| 27 | // OSC_PAL / 3.0 / 50.0 / 312.0 ~= 1137 |
| 28 | ssp1601_run(PicoSVPCycles * count); |
| 29 | |
| 30 | // test mode |
| 31 | //if (Pico.m.frame_count == 13) PicoPad[0] |= 0xff; |
| 32 | } |
| 33 | |
| 34 | |
| 35 | static int PicoSVPDma(unsigned int source, int len, unsigned short **srcp, unsigned short **limitp) |
| 36 | { |
| 37 | if (source < Pico.romsize) // Rom |
| 38 | { |
| 39 | source -= 2; |
| 40 | *srcp = (unsigned short *)(Pico.rom + (source&~1)); |
| 41 | *limitp = (unsigned short *)(Pico.rom + Pico.romsize); |
| 42 | return 1; |
| 43 | } |
| 44 | else if ((source & 0xfe0000) == 0x300000) |
| 45 | { |
| 46 | elprintf(EL_VDPDMA|EL_SVP, "SVP DmaSlow from %06x, len=%i", source, len); |
| 47 | source &= 0x1fffe; |
| 48 | source -= 2; |
| 49 | *srcp = (unsigned short *)(svp->dram + source); |
| 50 | *limitp = (unsigned short *)(svp->dram + sizeof(svp->dram)); |
| 51 | return 1; |
| 52 | } |
| 53 | else |
| 54 | elprintf(EL_VDPDMA|EL_SVP|EL_ANOMALY, "SVP FIXME unhandled DmaSlow from %06x, len=%i", source, len); |
| 55 | |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | |
| 60 | void PicoSVPInit(void) |
| 61 | { |
| 62 | void *tmp; |
| 63 | |
| 64 | elprintf(EL_SVP, "SVP init"); |
| 65 | |
| 66 | tmp = realloc(Pico.rom, 0x200000 + sizeof(*svp)); |
| 67 | if (tmp == NULL) |
| 68 | { |
| 69 | elprintf(EL_STATUS|EL_SVP, "OOM for SVP data"); |
| 70 | return; |
| 71 | } |
| 72 | |
| 73 | Pico.rom = tmp; |
| 74 | svp = (void *) ((char *)tmp + 0x200000); |
| 75 | memset(svp, 0, sizeof(*svp)); |
| 76 | |
| 77 | // init ok, setup hooks.. |
| 78 | PicoRead16Hook = PicoSVPRead16; |
| 79 | PicoWrite8Hook = PicoSVPWrite8; |
| 80 | PicoWrite16Hook = PicoSVPWrite16; |
| 81 | PicoDmaHook = PicoSVPDma; |
| 82 | PicoResetHook = PicoSVPReset; |
| 83 | PicoLineHook = PicoSVPLine; |
| 84 | } |
| 85 | |