mirror of
https://github.com/RaySollium99/picodrive.git
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d4ca252d92
git-svn-id: file:///home/notaz/opt/svn/PicoDrive@335 be3aeb3a-fb24-0410-a615-afba39da0efa
85 lines
1.8 KiB
C
85 lines
1.8 KiB
C
// The SVP chip emulator
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// (c) Copyright 2008, Grazvydas "notaz" Ignotas
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// Free for non-commercial use.
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// For commercial use, separate licencing terms must be obtained.
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#include "../../PicoInt.h"
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svp_t *svp = NULL;
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int PicoSVPCycles = 800; // cycles/line
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static void PicoSVPReset(void)
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{
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elprintf(EL_SVP, "SVP reset");
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memcpy(svp->iram_rom + 0x800, Pico.rom + 0x800, 0x20000 - 0x800);
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ssp1601_reset(&svp->ssp1601);
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}
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static void PicoSVPLine(int count)
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{
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// ???
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// OSC_NTSC / 3.0 / 60.0 / 262.0 ~= 1139
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// OSC_PAL / 3.0 / 50.0 / 312.0 ~= 1137
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ssp1601_run(PicoSVPCycles * count);
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// test mode
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//if (Pico.m.frame_count == 13) PicoPad[0] |= 0xff;
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}
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static int PicoSVPDma(unsigned int source, int len, unsigned short **srcp, unsigned short **limitp)
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{
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if (source < Pico.romsize) // Rom
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{
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source -= 2;
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*srcp = (unsigned short *)(Pico.rom + (source&~1));
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*limitp = (unsigned short *)(Pico.rom + Pico.romsize);
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return 1;
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}
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else if ((source & 0xfe0000) == 0x300000)
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{
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elprintf(EL_VDPDMA|EL_SVP, "SVP DmaSlow from %06x, len=%i", source, len);
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source &= 0x1fffe;
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source -= 2;
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*srcp = (unsigned short *)(svp->dram + source);
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*limitp = (unsigned short *)(svp->dram + sizeof(svp->dram));
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return 1;
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}
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else
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elprintf(EL_VDPDMA|EL_SVP|EL_ANOMALY, "SVP FIXME unhandled DmaSlow from %06x, len=%i", source, len);
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return 0;
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}
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void PicoSVPInit(void)
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{
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void *tmp;
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elprintf(EL_SVP, "SVP init");
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tmp = realloc(Pico.rom, 0x200000 + sizeof(*svp));
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if (tmp == NULL)
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{
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elprintf(EL_STATUS|EL_SVP, "OOM for SVP data");
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return;
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}
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Pico.rom = tmp;
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svp = (void *) ((char *)tmp + 0x200000);
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memset(svp, 0, sizeof(*svp));
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// init ok, setup hooks..
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PicoRead16Hook = PicoSVPRead16;
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PicoWrite8Hook = PicoSVPWrite8;
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PicoWrite16Hook = PicoSVPWrite16;
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PicoDmaHook = PicoSVPDma;
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PicoResetHook = PicoSVPReset;
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PicoLineHook = PicoSVPLine;
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}
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