/**

  * $Id: sh4trans.c,v 1.8 2007-10-08 12:06:01 nkeynes Exp $

  * 

  * SH4 translation core module. This part handles the non-target-specific

  * section of the translation.

  *

  * 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.

  */

 #include <assert.h>

 #include "eventq.h"

 #include "syscall.h"

 #include "sh4/sh4core.h"

 #include "sh4/sh4trans.h"

 #include "sh4/xltcache.h"

 uint32_t last_pc;

 void *last_code;

 /**

  * Execute a timeslice using translated code only (ie translate/execute loop)

  * Note this version does not support breakpoints

  */

 uint32_t sh4_xlat_run_slice( uint32_t nanosecs ) 

 {

     sh4r.slice_cycle = 0;

     if( sh4r.sh4_state != SH4_STATE_RUNNING ) {

 	if( sh4r.event_pending < nanosecs ) {

 	    sh4r.sh4_state = SH4_STATE_RUNNING;

 	    sh4r.slice_cycle = sh4r.event_pending;

 	}

     }

     void * (*code)() = NULL;

     while( sh4r.slice_cycle < nanosecs ) {

 	if( sh4r.event_pending <= sh4r.slice_cycle ) {

 	    if( sh4r.event_types & PENDING_EVENT ) {

 		event_execute();

 	    }

 	    /* Eventq execute may (quite likely) deliver an immediate IRQ */

 	    if( sh4r.event_types & PENDING_IRQ ) {

 		sh4_accept_interrupt();

 		code = NULL;

 	    }

 	}

 	if( code == NULL ) {

 	    if( sh4r.pc > 0xFFFFFF00 ) {

 		syscall_invoke( sh4r.pc );

 		sh4r.in_delay_slot = 0;

 		sh4r.pc = sh4r.pr;

 	    }

 	    code = xlat_get_code(sh4r.pc);

 	    if( code == NULL ) {

 		uint64_t ppa = mmu_vma_to_phys_exec( sh4r.pc );

 		if( ppa>>32 ) {

 		    // not found, exception

 		    ppa = mmu_vma_to_phys_exec( sh4r.pc );

 		    if( ppa>>32 ) {

 			// double fault - halt

 			dreamcast_stop();

 			ERROR( "Double fault - halting" );

 			return nanosecs;

 		    }

 		}

 		code = sh4_translate_basic_block( sh4r.pc );

 	    }

 	}

         last_pc = sh4r.pc;

         last_code = code;	

 	code = code();

     }

     if( sh4r.sh4_state != SH4_STATE_STANDBY ) {

 	TMU_run_slice( nanosecs );

 	SCIF_run_slice( nanosecs );

     }

     return nanosecs;

 }

 uint8_t *xlat_output;

 /**

  * Translate a linear basic block, ie all instructions from the start address

  * (inclusive) until the next branch/jump instruction or the end of the page

  * is reached.

  * @return the address of the translated block

  * eg due to lack of buffer space.

  */

 void * sh4_translate_basic_block( sh4addr_t start )

 {

     sh4addr_t pc = start;

     sh4addr_t lastpc = (pc&0xFFFFF000)+0x1000;

     int done;

     xlat_cache_block_t block = xlat_start_block( start );

     xlat_output = (uint8_t *)block->code;

     uint8_t *eob = xlat_output + block->size;

     sh4_translate_begin_block(pc);

     do {

 	if( eob - xlat_output < MAX_INSTRUCTION_SIZE ) {

 	    uint8_t *oldstart = block->code;

 	    block = xlat_extend_block( xlat_output - oldstart + MAX_INSTRUCTION_SIZE );

 	    xlat_output = block->code + (xlat_output - oldstart);

 	    eob = block->code + block->size;

 	}

 	done = sh4_translate_instruction( pc ); 

 	assert( xlat_output <= eob );

 	pc += 2;

 	if ( pc >= lastpc ) {

 	    done = 2;

 	}

     } while( !done );

     pc += (done - 2);

     if( eob - xlat_output < EPILOGUE_SIZE ) {

 	uint8_t *oldstart = block->code;

 	block = xlat_extend_block( xlat_output - oldstart + EPILOGUE_SIZE );

 	xlat_output = block->code + (xlat_output - oldstart);

     }	

     sh4_translate_end_block(pc);

     xlat_commit_block( xlat_output - block->code, pc-start );

     return block->code;

 }

 /**

  * Translate a linear basic block to a temporary buffer, execute it, and return

  * the result of the execution. The translation is discarded.

  */

 void *sh4_translate_and_run( sh4addr_t start )

 {

     unsigned char buf[65536];

     sh4addr_t pc = start;

     int done;

     xlat_output = buf;

     uint8_t *eob = xlat_output + sizeof(buf);

     sh4_translate_begin_block(pc);

     while( (done = sh4_translate_instruction( pc )) == 0 ) {

 	assert( (eob - xlat_output) >= MAX_INSTRUCTION_SIZE );

 	pc += 2;

     }

     pc+=2;

     sh4_translate_end_block(pc);

     void * (*code)() = (void *)buf;

     return code();

 }