/**

  * $Id$

  * 

  * SH4->x86 translation module

  *

  * 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 "sh4/xltcache.h"

 #include "dream.h"

 #include "mem.h"

 /** Maximum size of a translated instruction, in bytes. This includes potentially

  * writing the entire epilogue

  */

 #define MAX_INSTRUCTION_SIZE 256

 /** Maximum size of the translation epilogue (current real size is 116 bytes, so

  * allows a little room

  */

 #define EPILOGUE_SIZE 128

 /** Maximum number of recovery records for a translated block (2048 based on

  * 1 record per SH4 instruction in a 4K page).

  */

 #define MAX_RECOVERY_SIZE 2048

 /**

  * Translation flag - exit the current block but continue (eg exception handling)

  */

 #define XLAT_EXIT_CONTINUE 1

 /**

  * Translation flag - exit the current block and halt immediately (eg fatal error)

  */

 #define XLAT_EXIT_HALT 2

 /**

  * Translation flag - exit the current block and halt immediately for a system

  * breakpoint.

  */

 #define XLAT_EXIT_BREAKPOINT 3

 /**

  * Translation flag - exit the current block and continue after performing a full

  * system reset (dreamcast_reset())

  */

 #define XLAT_EXIT_SYSRESET 4

 /**

  * Translation flag - exit the current block and continue after the next IRQ.

  */

 #define XLAT_EXIT_SLEEP 5

 /**

  */

 uint32_t sh4_xlat_run_slice( uint32_t nanosecs );

 /**

  * Return true if translated code is currently running

  */

 gboolean sh4_xlat_is_running();

 /**

  * Initialize the translation engine (if required). Note xlat cache

  * must already be initialized.

  */

 void sh4_xlat_init();

 /**

  * Translate the specified block of code starting from the specified start

  * address until the first branch/jump instruction.

  */

 void *sh4_translate_basic_block( sh4addr_t start );

 /**

  * Add a recovery record for the current code generation position, with the

  * specified instruction count

  */

 void sh4_translate_add_recovery( uint32_t icount );

 extern uint8_t *xlat_output;

 extern struct xlat_recovery_record xlat_recovery[MAX_RECOVERY_SIZE];

 extern xlat_cache_block_t xlat_current_block;

 extern uint32_t xlat_recovery_posn;

 /******************************************************************************

  * Code generation - these methods must be provided by the

  * actual code gen (eg sh4x86.c) 

  ******************************************************************************/

 #define TARGET_X86 1

 void sh4_translate_init( void );

 void sh4_translate_begin_block( sh4addr_t pc );

 uint32_t sh4_translate_instruction( sh4addr_t pc );

 void sh4_translate_end_block( sh4addr_t pc );

 uint32_t sh4_translate_end_block_size();

 void sh4_translate_emit_breakpoint( sh4vma_t pc );

 typedef void (*unwind_thunk_t)(void);

 /**

  * From within the translator, (typically called from MMU exception handling routines)

  * immediately exit the current translation block (performing cleanup as necessary) and

  * return to sh4_xlat_run_slice(). Effectively a fast longjmp w/ xlat recovery.

  *

  * Note: The correct working of this method depends on the translator anticipating the

  * exception and generating the appropriate recovery block(s) - currently this means 

  * that it should ONLY be called from within the context of a memory read or write.

  *

  * @param is_completion If TRUE, exit after completing the current instruction (effectively),

  *   otherwise abort the current instruction with no effect. 

  * @param thunk A function to execute after perform xlat recovery, but before returning

  * to run_slice. If NULL, control returns directly.

  * @return This method never returns. 

  */

 void sh4_translate_unwind_stack( gboolean is_completion, unwind_thunk_t thunk );

 /**

  * From within the translator, immediately exit the current translation block with

  * the specified exit code (one of the XLAT_EXIT_* values).

  */

 void sh4_translate_exit( int exit_code );

 /**

  * From within the translator, exit the current block at the end of the 

  * current instruction, flush the translation cache (completely) and return

  * control to sh4_xlat_run_slice.

  */

 void sh4_translate_flush_cache( void );

 /**

  * Support function called from the translator when a breakpoint is hit.

  * Either returns immediately (to skip the breakpoint), or aborts the current

  * cycle and never returns.

  */

 void sh4_translate_breakpoint_hit( sh4vma_t pc );