/** * \addtogroup c64fs * @{ *//** * \file * Implementation of C64 file writes. * \author Adam Dunkels <adam@dunkels.com> * * The functions in this file are not included in the core Contiki * code, but must be explicitly linked by an application that that * wishes to be able to write to files. *//* * Copyright (c) 2003, Adam Dunkels. * All rights reserved.  * * Redistribution and use in source and binary forms, with or without  * modification, are permitted provided that the following conditions  * are met:  * 1. Redistributions of source code must retain the above copyright  *    notice, this list of conditions and the following disclaimer.  * 2. Redistributions in binary form must reproduce the above *    copyright notice, this list of conditions and the following *    disclaimer in the documentation and/or other materials provided *    with the distribution.  * 3. The name of the author may not be used to endorse or promote *    products derived from this software without specific prior *    written permission.   * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.   * * This file is part of the Contiki desktop environment  * * $Id: c64-fs-write.c,v 1.1 2007/05/23 23:11:28 oliverschmidt Exp $ * */#include "c64-dio.h"#include "c64-fs.h"#include <string.h>/* An *UGLY* implementation of c64_fs_write that only can be used to   overwrite a single block file. */extern unsigned char _c64_fs_filebuf[256];extern unsigned char _c64_fs_filebuftrack,  _c64_fs_filebufsect;/*-----------------------------------------------------------------------------------*//** * Write data to an open file. * * \note This function currently does not support writing to other than a single block file (cannot be more than 254 bytes long). * * \param f A pointer to a file descriptor previously opened with c64_fs_open(). * * \param buf A pointer to a buffer with data that should be written * to the file. * * \param len The length of the data that should be written. * * \return The number of bytes actually written. * *//*-----------------------------------------------------------------------------------*/int __fastcall__c64_fs_write(register struct c64_fs_file *f, char *buf, int len){  int i;  if(len <= 0) {    return 0;  }  /* Check if current block is already in buffer, and if not read it     from disk. */  if(_c64_fs_filebuftrack != f->track ||     _c64_fs_filebufsect != f->sect) {    _c64_fs_filebuftrack = f->track;    _c64_fs_filebufsect = f->sect;    c64_dio_read_block(_c64_fs_filebuftrack,		       _c64_fs_filebufsect,		       _c64_fs_filebuf);  }  i = 256 - f->ptr;  if(len < i) {    i = len;  }  memcpy(&_c64_fs_filebuf[f->ptr], buf, i);  f->ptr += i;  if(_c64_fs_filebuf[0] == 0 &&     f->ptr > _c64_fs_filebuf[1]) {    _c64_fs_filebuf[1] = f->ptr;      }  c64_dio_write_block(_c64_fs_filebuftrack,		      _c64_fs_filebufsect,		      _c64_fs_filebuf);    return i;}/*-----------------------------------------------------------------------------------*//** @} */