BizHawk/waterbox/picodrive/pico/carthw/svp/svp.c

143 lines
4.0 KiB
C

/*
* The SVP chip emulator
*
* Copyright (c) Gražvydas "notaz" Ignotas, 2008
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the organization nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <pico/pico_int.h>
svp_t *svp = NULL;
int PicoSVPCycles = 850; // cycles/line, just a guess
static int svp_dyn_ready = 0;
static void PicoSVPReset(void)
{
elprintf(EL_SVP, "SVP reset");
memcpy(svp->iram_rom + 0x800, Pico.rom + 0x800, 0x20000 - 0x800);
ssp1601_reset(&svp->ssp1601);
#ifdef _SVP_DRC
if ((PicoOpt & POPT_EN_DRC) && svp_dyn_ready)
ssp1601_dyn_reset(&svp->ssp1601);
#endif
}
static void PicoSVPLine(void)
{
int count = 1;
#if defined(__arm__) || defined(PSP)
// performance hack
static int delay_lines = 0;
delay_lines++;
if ((Pico.m.scanline&0xf) != 0xf && Pico.m.scanline != 261 && Pico.m.scanline != 311)
return;
count = delay_lines;
delay_lines = 0;
#endif
#ifdef _SVP_DRC
if ((PicoOpt & POPT_EN_DRC) && svp_dyn_ready)
ssp1601_dyn_run(PicoSVPCycles * count);
else
#endif
{
ssp1601_run(PicoSVPCycles * count);
svp_dyn_ready = 0; // just in case
}
// test mode
//if (Pico.m.frame_count == 13) PicoPad[0] |= 0xff;
}
static int PicoSVPDma(unsigned int source, int len, unsigned short **srcp, unsigned short **limitp)
{
if (source < Pico.romsize) // Rom
{
source -= 2;
*srcp = (unsigned short *)(Pico.rom + (source&~1));
*limitp = (unsigned short *)(Pico.rom + Pico.romsize);
return 1;
}
else if ((source & 0xfe0000) == 0x300000)
{
elprintf(EL_VDPDMA|EL_SVP, "SVP DmaSlow from %06x, len=%i", source, len);
source &= 0x1fffe;
source -= 2;
*srcp = (unsigned short *)(svp->dram + source);
*limitp = (unsigned short *)(svp->dram + sizeof(svp->dram));
return 1;
}
else
elprintf(EL_VDPDMA|EL_SVP|EL_ANOMALY, "SVP FIXME unhandled DmaSlow from %06x, len=%i", source, len);
return 0;
}
void PicoSVPInit(void)
{
#ifdef _SVP_DRC
// this is to unmap tcache and make
// mem available for large ROMs, MCD, etc.
drc_cmn_cleanup();
#endif
}
void PicoSVPStartup(void)
{
int ret;
elprintf(EL_STATUS, "SVP startup");
ret = PicoCartResize(Pico.romsize + sizeof(*svp));
if (ret != 0) {
elprintf(EL_STATUS|EL_SVP, "OOM for SVP data");
return;
}
svp = (void *) ((char *)Pico.rom + Pico.romsize);
memset(svp, 0, sizeof(*svp));
// init SVP compiler
svp_dyn_ready = 0;
#ifdef _SVP_DRC
if (PicoOpt & POPT_EN_DRC) {
if (ssp1601_dyn_startup())
return;
svp_dyn_ready = 1;
}
#endif
// init ok, setup hooks..
PicoCartMemSetup = PicoSVPMemSetup;
PicoDmaHook = PicoSVPDma;
PicoResetHook = PicoSVPReset;
PicoLineHook = PicoSVPLine;
PicoAHW |= PAHW_SVP;
}