/**

 * $Id: sh4.c,v 1.6 2007-10-31 09:02:18 nkeynes Exp $

 * 

 * SH4 parent module for all CPU modes and SH4 peripheral

 * modules.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#define MODULE sh4_module

#include <math.h>

#include "dream.h"

#include "dreamcast.h"

#include "sh4/sh4core.h"

#include "sh4/sh4mmio.h"

#include "sh4/intc.h"

#include "sh4/xltcache.h"

#include "sh4/sh4stat.h"

#include "mem.h"

#include "clock.h"

#include "syscall.h"

#define EXV_EXCEPTION    0x100  /* General exception vector */

#define EXV_TLBMISS      0x400  /* TLB-miss exception vector */

#define EXV_INTERRUPT    0x600  /* External interrupt vector */

void sh4_init( void );

void sh4_x86_init( void );

void sh4_reset( void );

void sh4_start( void );

void sh4_stop( void );

void sh4_save_state( FILE *f );

int sh4_load_state( FILE *f );

uint32_t sh4_run_slice( uint32_t );

uint32_t sh4_xlat_run_slice( uint32_t );

struct dreamcast_module sh4_module = { "SH4", sh4_init, sh4_reset, 

				       NULL, sh4_run_slice, sh4_stop,

				       sh4_save_state, sh4_load_state };

struct sh4_registers sh4r;

struct breakpoint_struct sh4_breakpoints[MAX_BREAKPOINTS];

int sh4_breakpoint_count = 0;

extern char *sh4_main_ram;

void sh4_set_use_xlat( gboolean use )

{

    if( use ) {

	xlat_cache_init();

	sh4_x86_init();

	sh4_module.run_time_slice = sh4_xlat_run_slice;

    } else {

	sh4_module.run_time_slice = sh4_run_slice;

    }

}

void sh4_init(void)

{

    register_io_regions( mmio_list_sh4mmio );

    sh4_main_ram = mem_get_region_by_name(MEM_REGION_MAIN);

    MMU_init();

    sh4_reset();

}

void sh4_reset(void)

{

    if(	sh4_module.run_time_slice == sh4_xlat_run_slice ) {

	xlat_flush_cache();

    }

    /* zero everything out, for the sake of having a consistent state. */

    memset( &sh4r, 0, sizeof(sh4r) );

    /* Resume running if we were halted */

    sh4r.sh4_state = SH4_STATE_RUNNING;

    sh4r.pc    = 0xA0000000;

    sh4r.new_pc= 0xA0000002;

    sh4r.vbr   = 0x00000000;

    sh4r.fpscr = 0x00040001;

    sh4r.sr    = 0x700000F0;

    sh4r.fr_bank = &sh4r.fr[0][0];

    /* Mem reset will do this, but if we want to reset _just_ the SH4... */

    MMIO_WRITE( MMU, EXPEVT, EXC_POWER_RESET );

    /* Peripheral modules */

    CPG_reset();

    INTC_reset();

    MMU_reset();

    TMU_reset();

    SCIF_reset();

    sh4_stats_reset();

}

void sh4_stop(void)

{

}

void sh4_save_state( FILE *f )

{

    if(	sh4_module.run_time_slice == sh4_xlat_run_slice ) {

	/* If we were running with the translator, update new_pc and in_delay_slot */

	sh4r.new_pc = sh4r.pc+2;

	sh4r.in_delay_slot = FALSE;

    }

    fwrite( &sh4r, sizeof(sh4r), 1, f );

    MMU_save_state( f );

    INTC_save_state( f );

    TMU_save_state( f );

    SCIF_save_state( f );

}

int sh4_load_state( FILE * f )

{

    if(	sh4_module.run_time_slice == sh4_xlat_run_slice ) {

	xlat_flush_cache();

    }

    fread( &sh4r, sizeof(sh4r), 1, f );

    sh4r.fr_bank = &sh4r.fr[(sh4r.fpscr&FPSCR_FR)>>21][0]; // Fixup internal FR pointer

    MMU_load_state( f );

    INTC_load_state( f );

    TMU_load_state( f );

    return SCIF_load_state( f );

}

void sh4_set_breakpoint( uint32_t pc, int type )

{

    sh4_breakpoints[sh4_breakpoint_count].address = pc;

    sh4_breakpoints[sh4_breakpoint_count].type = type;

    sh4_breakpoint_count++;

}

gboolean sh4_clear_breakpoint( uint32_t pc, int type )

{

    int i;

    for( i=0; i<sh4_breakpoint_count; i++ ) {

	if( sh4_breakpoints[i].address == pc && 

	    sh4_breakpoints[i].type == type ) {

	    while( ++i < sh4_breakpoint_count ) {

		sh4_breakpoints[i-1].address = sh4_breakpoints[i].address;

		sh4_breakpoints[i-1].type = sh4_breakpoints[i].type;

	    }

	    sh4_breakpoint_count--;

	    return TRUE;

	}

    }

    return FALSE;

}

int sh4_get_breakpoint( uint32_t pc )

{

    int i;

    for( i=0; i<sh4_breakpoint_count; i++ ) {

	if( sh4_breakpoints[i].address == pc )

	    return sh4_breakpoints[i].type;

    }

    return 0;

}

void sh4_set_pc( int pc )

{

    sh4r.pc = pc;

    sh4r.new_pc = pc+2;

}

/******************************* Support methods ***************************/

static void sh4_switch_banks( )

{

    uint32_t tmp[8];

    memcpy( tmp, sh4r.r, sizeof(uint32_t)*8 );

    memcpy( sh4r.r, sh4r.r_bank, sizeof(uint32_t)*8 );

    memcpy( sh4r.r_bank, tmp, sizeof(uint32_t)*8 );

}

void sh4_write_sr( uint32_t newval )

{

    if( (newval ^ sh4r.sr) & SR_RB )

        sh4_switch_banks();

    sh4r.sr = newval;

    sh4r.t = (newval&SR_T) ? 1 : 0;

    sh4r.s = (newval&SR_S) ? 1 : 0;

    sh4r.m = (newval&SR_M) ? 1 : 0;

    sh4r.q = (newval&SR_Q) ? 1 : 0;

    intc_mask_changed();

}

uint32_t sh4_read_sr( void )

{

    /* synchronize sh4r.sr with the various bitflags */

    sh4r.sr &= SR_MQSTMASK;

    if( sh4r.t ) sh4r.sr |= SR_T;

    if( sh4r.s ) sh4r.sr |= SR_S;

    if( sh4r.m ) sh4r.sr |= SR_M;

    if( sh4r.q ) sh4r.sr |= SR_Q;

    return sh4r.sr;

}

#define RAISE( x, v ) do{			\

    if( sh4r.vbr == 0 ) { \

        ERROR( "%08X: VBR not initialized while raising exception %03X, halting", sh4r.pc, x ); \

        dreamcast_stop(); return FALSE;	\

    } else { \

        sh4r.spc = sh4r.pc;	\

        sh4r.ssr = sh4_read_sr(); \

        sh4r.sgr = sh4r.r[15]; \

        MMIO_WRITE(MMU,EXPEVT,x); \

        sh4r.pc = sh4r.vbr + v; \

        sh4r.new_pc = sh4r.pc + 2; \

        sh4_write_sr( sh4r.ssr |SR_MD|SR_BL|SR_RB ); \

	if( sh4r.in_delay_slot ) { \

	    sh4r.in_delay_slot = 0; \

	    sh4r.spc -= 2; \

	} \

    } \

    return TRUE; } while(0)

/**

 * Raise a general CPU exception for the specified exception code.

 * (NOT for TRAPA or TLB exceptions)

 */

gboolean sh4_raise_exception( int code )

{

    RAISE( code, EXV_EXCEPTION );

}

gboolean sh4_raise_trap( int trap )

{

    MMIO_WRITE( MMU, TRA, trap<<2 );

    return sh4_raise_exception( EXC_TRAP );

}

gboolean sh4_raise_slot_exception( int normal_code, int slot_code ) {

    if( sh4r.in_delay_slot ) {

	return sh4_raise_exception(slot_code);

    } else {

	return sh4_raise_exception(normal_code);

    }

}

gboolean sh4_raise_tlb_exception( int code )

{

    RAISE( code, EXV_TLBMISS );

}

void sh4_accept_interrupt( void )

{

    uint32_t code = intc_accept_interrupt();

    sh4r.ssr = sh4_read_sr();

    sh4r.spc = sh4r.pc;

    sh4r.sgr = sh4r.r[15];

    sh4_write_sr( sh4r.ssr|SR_BL|SR_MD|SR_RB );

    MMIO_WRITE( MMU, INTEVT, code );

    sh4r.pc = sh4r.vbr + 0x600;

    sh4r.new_pc = sh4r.pc + 2;

    //    WARN( "Accepting interrupt %03X, from %08X => %08X", code, sh4r.spc, sh4r.pc );

}

void signsat48( void )

{

    if( ((int64_t)sh4r.mac) < (int64_t)0xFFFF800000000000LL )

	sh4r.mac = 0xFFFF800000000000LL;

    else if( ((int64_t)sh4r.mac) > (int64_t)0x00007FFFFFFFFFFFLL )

	sh4r.mac = 0x00007FFFFFFFFFFFLL;

}

void sh4_fsca( uint32_t anglei, float *fr )

{

    float angle = (((float)(anglei&0xFFFF))/65536.0) * 2 * M_PI;

    *fr++ = cosf(angle);

    *fr = sinf(angle);

}

void sh4_sleep(void)

{

    if( MMIO_READ( CPG, STBCR ) & 0x80 ) {

	sh4r.sh4_state = SH4_STATE_STANDBY;

    } else {

	sh4r.sh4_state = SH4_STATE_SLEEP;

    }

}

/**

 * Compute the matrix tranform of fv given the matrix xf.

 * Both fv and xf are word-swapped as per the sh4r.fr banks

 */

void sh4_ftrv( float *target, float *xf )

{

    float fv[4] = { target[1], target[0], target[3], target[2] };

    target[1] = xf[1] * fv[0] + xf[5]*fv[1] +

	xf[9]*fv[2] + xf[13]*fv[3];

    target[0] = xf[0] * fv[0] + xf[4]*fv[1] +

	xf[8]*fv[2] + xf[12]*fv[3];

    target[3] = xf[3] * fv[0] + xf[7]*fv[1] +

	xf[11]*fv[2] + xf[15]*fv[3];

    target[2] = xf[2] * fv[0] + xf[6]*fv[1] +

	xf[10]*fv[2] + xf[14]*fv[3];

}