/*****************************************************************************//*                                                                           *//*                                   em.h                                    *//*                                                                           *//*                      API for extended memory access                       *//*                                                                           *//*                                                                           *//*                                                                           *//* (C) 2002-2003 Ullrich von Bassewitz                                       *//*               R鰉erstrasse 52                                             *//*               D-70794 Filderstadt                                         *//* EMail:        uz@cc65.org                                                 *//*                                                                           *//*                                                                           *//* This software is provided 'as-is', without any expressed or implied       *//* warranty.  In no event will the authors be held liable for any damages    *//* arising from the use of this software.                                    *//*                                                                           *//* Permission is granted to anyone to use this software for any purpose,     *//* including commercial applications, and to alter it and redistribute it    *//* freely, subject to the following restrictions:                            *//*                                                                           *//* 1. The origin of this software must not be misrepresented; you must not   *//*    claim that you wrote the original software. If you use this software   *//*    in a product, an acknowledgment in the product documentation would be  *//*    appreciated but is not required.                                       *//* 2. Altered source versions must be plainly marked as such, and must not   *//*    be misrepresented as being the original software.                      *//* 3. This notice may not be removed or altered from any source              *//*    distribution.                                                          *//*                                                                           *//*****************************************************************************/#ifndef _EM_H#define _EM_H/*****************************************************************************//*                                  Definitions                              *//*****************************************************************************//* Size of an extended memory page */#define EM_PAGE_SIZE          256/* Error codes */#define EM_ERR_OK               0       /* No error */#define EM_ERR_NO_DRIVER        1       /* No driver available */#define EM_ERR_CANNOT_LOAD      2       /* Error loading driver */#define EM_ERR_INV_DRIVER       3       /* Invalid driver */#define EM_ERR_NO_DEVICE        4       /* Device (hardware) not found *//* Parameters for the em_copy_... functions. NOTE: The first seven bytes * have the same order and alignment as needed for the Commodore REU, so * don't change the order without changing the assembler file that defines * the struct offsets and the code in the REU driver. */struct em_copy {    void*           buf;        /* Memory buffer to copy from or to */    unsigned char   offs;       /* Offset into page */    unsigned        page;       /* Starting page to copy from or to */    unsigned        count;      /* Number of bytes to copy */    unsigned char   unused;     /* Make the size 8 bytes */};/*****************************************************************************//* 	      	       	      	   Functions	     			     *//*****************************************************************************/unsigned char __fastcall__ em_load_driver (const char* driver);/* Load and install an extended memory driver. Return an error code. */unsigned char __fastcall__ em_unload (void);/* Uninstall, then unload the currently loaded driver. */unsigned char __fastcall__ em_install (void* driver);/* Install an already loaded driver. Return an error code. */unsigned char __fastcall__ em_uninstall (void);/* Uninstall the currently loaded driver and return an error code. * Note: This call does not free allocated memory. */unsigned __fastcall__ em_pagecount (void);/* Return the total number of 256 byte pages available in extended memory. */void* __fastcall__ em_map (unsigned page);/* Unmap the current page from memory and map a new one. The function returns * a pointer to the location of the page in memory. Note: Without calling * em_commit, the old contents of the memory window may be lost! */void* __fastcall__ em_use (unsigned page);/* Tell the driver that the memory window is associated with a given page. * This call is very similar to em_map. The difference is that the driver * does not necessarily transfer the current contents of the extended * memory into the returned window. If you're going to just write to the * window and the current contents of the window are invalid or no longer * use, this call may perform better than em_map. */void __fastcall__ em_commit (void);/* Commit changes in the memory window to extended storage. If the contents * of the memory window have been changed, these changes may be lost if * em_map, em_copyfrom or em_copyto are called without calling em_commit * first. Note: Not calling em_commit does not mean that the changes are * discarded, it does just mean that some drivers will discard the changes. */void __fastcall__ em_copyfrom (const struct em_copy* copy_data);/* Copy from extended into linear memory. Note: This may invalidate the * currently mapped page. */void __fastcall__ em_copyto (const struct em_copy* copy_data);/* Copy from linear into extended memory. Note: This may invalidate the * currently mapped page. *//* End of em.h */               #endif