/* */
/* */
/* */
-/* (C) 2002 Ullrich von Bassewitz */
-/* Wacholderweg 14 */
-/* D-70597 Stuttgart */
-/* EMail: uz@musoftware.de */
+/* (C) 2002-2012, Ullrich von Bassewitz */
+/* Roemerstrasse 52 */
+/* D-70794 Filderstadt */
+/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* Size of an extended memory page */
#define EM_PAGE_SIZE 256
-/* Driver constants */
-#define EM_DRV_DETECT 0
-
/* 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 */
+#define EM_ERR_INSTALLED 5 /* A driver is already installed */
-/* Parameters for the em_copy_... functions */
+/* 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 {
- unsigned page; /* Starting page to copy from or to */
- unsigned char offs; /* Offset into page */
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 */
+/* Functions */
/*****************************************************************************/
-unsigned char __fastcall__ em_load (unsigned char driver);
-/* Load the extended memory driver and return an error code. */
-
unsigned char __fastcall__ em_load_driver (const char* driver);
-/* Load an extended memory driver and return an error code */
+/* Load and install an extended memory driver. Return an error code. */
unsigned char em_unload (void);
-/* Unload the currently loaded driver. */
+/* 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 em_uninstall (void);
+/* Uninstall the currently loaded driver and return an error code.
+** Note: This call does not free allocated memory.
+*/
unsigned 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.
- */
-
-void* __fastcall__ em_mapclean (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. This function differs from
- * em_map_page() in that it will discard the contents of the currently mapped
- * page, assuming that the page has not been modified or that the modifications
- * are no longer needed, if this leads to better performance. NOTE: This does
- * NOT mean that the contents of currently mapped page are always discarded!
- */
+** 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 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.
- */
+** 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.
- */
+** currently mapped page.
+*/
projects / cc65 / blobdiff