/*---------------------------------------------------------------------*

        Copyright (C) 1998 Nintendo.

        

        $RCSfile: dd_checksum.c,v $

        $Revision: 1.1.1.1 $

        $Date: 2003/01/17 23:03:19 $

 *---------------------------------------------------------------------*/



/* Read/Write check functions */

/*  Please modify the following functions to suit the application . */



#define CHECK_VAGUE 256



s32

dd_checkSum(void)

{

  /*  Checks the final 4 bytes of the designated area. */

  s32 i;

  u32 sum=0,*cs;



  u8  *buf = _rwbuf;



  for(i = 0; i < (s32)dd_stat.buffer_size - CHECK_VAGUE - 4; i += CHECK_VAGUE , buf += CHECK_VAGUE )

    {

        sum += *buf;

    }



  buf = _rwbuf;

  cs = (u32 *)((u32)buf + dd_stat.buffer_size - 4);

  

  return (*cs == sum) ?  LEO_ERROR_GOOD : LEO_ERROR_CHECKSUM;

}



s32

dd_makeSum(void)

{

  /*  Overwrites the final 4 bytes of the designated area with the checksum. */

  /*  Thus the actual size (specified size - 4) of the transferred data is in bytes. */



  s32 i;

  u8  *buf;

  u32 sum=0,*cs;



  buf = _rwbuf;



   for(i = 0; i < (s32)dd_stat.buffer_size - CHECK_VAGUE - 4 ; i += CHECK_VAGUE , buf += CHECK_VAGUE )

    {

        sum += *buf;

    }

 

  buf = _rwbuf;

  cs = (u32 *)((u32)buf + dd_stat.buffer_size - 4);

  *cs = sum;



  return -1;

}



s32

dd_restoreData( void )

{

  /*

   * A routine to restore data at damaged LBAs.

   * Note that lost data content essentially cannot be returned to its original state.

   * This function simply rewrites the contents of the current buffer.

   */



  s32 lba_size,ret;

  TDDStatus _keep;



  bcopy( &dd_stat,&_keep,sizeof(TDDStatus));

  dd_freeze( ERRMES__NOW_IN_RESTORE ); /* Keeps the external response. */



  LeoByteToLBA(  dd_stat.position , (u32)dd_stat.buffer_size , &lba_size);

  while( ( ret = dd_lbaWrite( dd_stat.position ,lba_size ) ) & DDSTAT_CONTINUE ) 

	dd_wait();

  bcopy( &_keep,&dd_stat,sizeof(TDDStatus));



  dd_closeDialog(0);

  

  return ret ? DDSTAT_DEAD : DDSTAT_GOOD;

}