picodrive/pico/carthw/svp/svp.c

// The SVP chip emulator

// (c) Copyright 2008, Grazvydas "notaz" Ignotas
// Free for non-commercial use.

// For commercial use, separate licencing terms must be obtained.


#include "../../pico_int.h"
#include "compiler.h"
#if defined(__linux__) && defined(ARM)
#include <sys/mman.h>
#endif

svp_t *svp = NULL;
int PicoSVPCycles = 850; // cycles/line, just a guess
static int svp_dyn_ready = 0;

/* save state stuff */
typedef enum {
	CHUNK_IRAM = CHUNK_CARTHW,
	CHUNK_DRAM,
	CHUNK_SSP
} chunk_name_e;

static carthw_state_chunk svp_states[] =
{
	{ CHUNK_IRAM, 0x800,                 NULL },
	{ CHUNK_DRAM, sizeof(svp->dram),     NULL },
	{ CHUNK_SSP,  sizeof(svp->ssp1601) - sizeof(svp->ssp1601.drc),  NULL },
	{ 0,          0,                     NULL }
};


static void PicoSVPReset(void)
{
	elprintf(EL_SVP, "SVP reset");

	memcpy(svp->iram_rom + 0x800, Pico.rom + 0x800, 0x20000 - 0x800);
	ssp1601_reset(&svp->ssp1601);
#ifndef PSP
	if ((PicoOpt&POPT_EN_SVP_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

#ifndef PSP
	if ((PicoOpt&POPT_EN_SVP_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)
{
#if defined(__linux__) && defined(ARM)
	int ret;
	ret = munmap(tcache, SSP_DRC_SIZE);
	printf("munmap tcache: %i\n", ret);
#endif
}


static void PicoSVPShutdown(void)
{
#if defined(__linux__) && defined(ARM)
	// also unmap tcache
	PicoSVPInit();
#endif
}


void PicoSVPStartup(void)
{
	void *tmp;

	elprintf(EL_SVP, "SVP init");

	tmp = realloc(Pico.rom, 0x200000 + sizeof(*svp));
	if (tmp == NULL)
	{
		elprintf(EL_STATUS|EL_SVP, "OOM for SVP data");
		return;
	}

	//PicoOpt &= ~0x20000;
	Pico.rom = tmp;
	svp = (void *) ((char *)tmp + 0x200000);
	memset(svp, 0, sizeof(*svp));

#if defined(__linux__) && defined(ARM)
	tmp = mmap(tcache, SSP_DRC_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
	printf("mmap tcache: %p, asked %p\n", tmp, tcache);
#endif

	// init SVP compiler
	svp_dyn_ready = 0;
#ifndef PSP
	if (PicoOpt&POPT_EN_SVP_DRC) {
		if (ssp1601_dyn_startup()) return;
		svp_dyn_ready = 1;
	}
#endif

	// init ok, setup hooks..
	PicoRead16Hook = PicoSVPRead16;
	PicoWrite8Hook = PicoSVPWrite8;
	PicoWrite16Hook = PicoSVPWrite16;
	PicoDmaHook = PicoSVPDma;
	PicoResetHook = PicoSVPReset;
	PicoLineHook = PicoSVPLine;
	PicoCartUnloadHook = PicoSVPShutdown;

	// save state stuff
	svp_states[0].ptr = svp->iram_rom;
	svp_states[1].ptr = svp->dram;
	svp_states[2].ptr = &svp->ssp1601;
	carthw_chunks = svp_states;
	PicoAHW |= PAHW_SVP;
}