/*
- * Extended memory overlay demo program.
- *
- * 2012-17-07, Oliver Schmidt (ol.sc@web.de)
- *
- */
+** Extended memory overlay demo program.
+**
+** Shows how to combine multiple cc65 features
+** incl. overlays and extended memory drivers.
+**
+** 2012-17-07, Oliver Schmidt (ol.sc@web.de)
+**
+*/
#include <string.h>
#include <stdio.h>
-#include <fcntl.h>
-#include <unistd.h>
+#include <stdlib.h>
#include <dirent.h>
#include <em.h>
-#include <conio.h>
+#include <cc65.h>
+#ifndef __CBM__
+#include <fcntl.h>
+#include <unistd.h>
+#else
+#include <cbm.h>
+#include <device.h>
+#endif
/* The symbols _OVERLAY?_LOAD__ and _OVERLAY?_SIZE__ were generated by the
- * linker. They contain the overlay area address and size specific to a
- * certain program.
- */
-extern void _OVERLAY1_LOAD__, _OVERLAY1_SIZE__;
-extern void _OVERLAY2_LOAD__, _OVERLAY2_SIZE__;
-extern void _OVERLAY3_LOAD__, _OVERLAY3_SIZE__;
-extern void _OVERLAY4_LOAD__, _OVERLAY4_SIZE__;
+** linker. They contain the overlay area address and size specific to a
+** certain program.
+*/
+extern void _OVERLAY1_LOAD__[], _OVERLAY1_SIZE__[];
+extern void _OVERLAY2_LOAD__[], _OVERLAY2_SIZE__[];
+extern void _OVERLAY3_LOAD__[], _OVERLAY3_SIZE__[];
struct {
char *name;
void *addr;
unsigned size;
} overlay[] =
- {{"multdemo.1", -1, &_OVERLAY1_LOAD__, (unsigned)&_OVERLAY1_SIZE__},
- {"multdemo.2", -1, &_OVERLAY2_LOAD__, (unsigned)&_OVERLAY2_SIZE__},
- {"multdemo.3", -1, &_OVERLAY3_LOAD__, (unsigned)&_OVERLAY3_SIZE__},
- {"multdemo.4", -1, &_OVERLAY4_LOAD__, (unsigned)&_OVERLAY4_SIZE__}};
-
-/* Copy overlays into extended memory up to overlay 3. Overlay 4 is known to
- * to be loaded only once for onetime initialization purposes so there's no
- * use in allocating extended memory for it.
- */
-#define MAX_EM_OVERLAY 3
-
-/* Search for up to 10 extended memory drivers.
- */
-#define MAX_EM_DRIVER 10
+ {{"multdemo.1", -1, _OVERLAY1_LOAD__, (unsigned)_OVERLAY1_SIZE__},
+ {"multdemo.2", -1, _OVERLAY2_LOAD__, (unsigned)_OVERLAY2_SIZE__},
+ {"multdemo.3", -1, _OVERLAY3_LOAD__, (unsigned)_OVERLAY3_SIZE__}};
/* Functions resident in an overlay can call back functions resident in the
- * main program at any time without any precautions. The function log() is
- * an example for such a function resident in the main program.
- */
+** main program at any time without any precautions. The function log() is
+** an example for such a function resident in the main program.
+*/
void log (char *msg)
{
/* Functions resident in an overlay can access all program variables and
- * constants at any time without any precautions because those are never
- * placed in overlays. The string constant below is an example for such
- * a constant resident in the main program.
- */
+ ** constants at any time without any precautions because those are never
+ ** placed in overlays. The string constant below is an example for such
+ ** a constant resident in the main program.
+ */
printf ("Log: %s\n", msg);
}
/* In a real-world overlay program one would probably not use a #pragma but
- * rather place the all the code of certain source files into the overlay by
- * compiling them with --code-name OVERLAY1.
- */
+** rather place all the code of certain source files into the overlay by
+** compiling them with --code-name OVERLAY1.
+*/
#pragma code-name (push, "OVERLAY1");
void foo (void)
#pragma code-name(pop);
-#pragma code-name (push, "OVERLAY4");
-
unsigned char loademdriver (void)
{
- static char emd[MAX_EM_DRIVER][FILENAME_MAX];
- DIR* dir;
- struct dirent* ent;
+ DIR *dir;
+ struct dirent *ent;
+ char *emd = NULL;
unsigned char max = 0;
unsigned char num;
}
printf ("Dbg: Memorizing file %s\n", ent->d_name);
- strcpy (emd[max], ent->d_name);
- if (++max == MAX_EM_DRIVER) {
- break;
- }
+ emd = realloc (emd, FILENAME_MAX * (max + 1));
+ strcpy (emd + FILENAME_MAX * max++, ent->d_name);
}
closedir (dir);
for (num = 0; num < max; ++num) {
- printf ("Dbg: Trying emdriver %s\n", emd[num]);
- if (em_load_driver (emd[num]) == EM_ERR_OK) {
- printf ("Dbg: Loaded emdriver %s\n", emd[num]);
- return 1;
- }
-
- printf ("Dbg: Emdriver %s failed\n", emd[num]);
- }
- return 0;
-}
+ char *drv;
-void copyoverlays (void)
-{
- unsigned page = 0;
- unsigned char num;
-
- for (num = 0; num < MAX_EM_OVERLAY; ++num) {
- int file;
- int size;
-
- if ((overlay[num].size + EM_PAGE_SIZE - 1) / EM_PAGE_SIZE >
- em_pagecount () - page) {
- printf ("Dbg: Not enough memory for overlay %u\n", num + 1);
- continue;
- }
-
- printf ("Dbg: Reading overlay file %s\n", overlay[num].name);
- file = open (overlay[num].name, O_RDONLY);
- if (file == -1) {
- log ("Opening overlay file failed");
- continue;
- }
-
- overlay[num].page = page;
- size = overlay[num].size;
- while (size) {
- void *buf;
-
- /* In general one could as well use em_copyto() to copy a fully
- * loaded overlay into extended memory in one step. However the
- * "streaming" of an overlay from disk to extended memory shown
- * here has two advantages:
- * - It can be done from another overlay (like done here).
- * - It avoids unnecessary double buffering with emdrivers that
- * provide a hardware memory window.
- */
- buf = em_use (page++);
- size -= read (file, buf, EM_PAGE_SIZE);
- em_commit ();
+ drv = emd + FILENAME_MAX * num;
+ printf ("Dbg: Trying emdriver %s\n", drv);
+ if (em_load_driver (drv) == EM_ERR_OK) {
+ printf ("Dbg: Loaded emdriver %s\n", drv);
+ free (emd);
+ return 1;
}
- printf ("Dbg: Stored overlay %u in pages %u-%u\n",
- num + 1, overlay[num].page, page - 1);
-
- close (file);
+ printf ("Dbg: Emdriver %s failed\n", drv);
}
-}
-#pragma code-name(pop);
+ free (emd);
+ return 0;
+}
unsigned char loadoverlay (unsigned char num)
{
if (overlay[num - 1].page < 0) {
+#ifndef __CBM__
+
int file;
printf ("Dbg: Loading overlay %u from file\n", num);
read (file, overlay[num - 1].addr,
overlay[num - 1].size);
close (file);
+
+#else
+
+ if (cbm_load (overlay[num - 1].name, getcurrentdevice (), NULL) == 0) {
+ log ("Loading overlay file failed");
+ return 0;
+ }
+
+#endif
return 1;
} else {
struct em_copy copyinfo;
}
}
-void main (void)
+
+void copyoverlays (void)
{
- if (loadoverlay (4)) {
- log ("Loading extended memory driver");
- if (loademdriver ()) {
- log ("Copying overlays into ext. memory");
- copyoverlays ();
- } else {
- log ("No extended memory driver found");
+ unsigned page = 0;
+ unsigned char num;
+
+ for (num = 0; num < sizeof (overlay) / sizeof (overlay[0]); ++num) {
+ struct em_copy copyinfo;
+ unsigned size = (overlay[num].size + EM_PAGE_SIZE - 1) / EM_PAGE_SIZE;
+
+ if (size > em_pagecount () - page) {
+ printf ("Dbg: Not enough memory for overlay %u\n", num + 1);
+ continue;
}
+
+ if (loadoverlay (num + 1) == 0)
+ continue;
+
+ copyinfo.offs = 0;
+ copyinfo.page = page;
+ copyinfo.buf = overlay[num].addr;
+ copyinfo.count = overlay[num].size;
+ em_copyto (©info);
+
+ overlay[num].page = page;
+ page += size;
+
+ printf ("Dbg: Stored overlay %u in pages %u-%u\n",
+ num + 1, overlay[num].page, page - 1);
+ }
+}
+
+
+void main (void)
+{
+ log ("Loading extended memory driver");
+ if (loademdriver ()) {
+ log ("Copying overlays into ext. memory");
+ copyoverlays ();
+ } else {
+ log ("No extended memory driver found");
}
log ("Press any key...");
- cgetc ();
+ getchar ();
if (loadoverlay (1)) {
log ("Calling overlay 1 from main");
/* The linker makes sure that the call to foo() ends up at the right mem
- * addr. However it's up to user to make sure that the - right - overlay
- * is actually loaded before making the the call.
- */
+ ** addr. However it's up to user to make sure that the - right - overlay
+ ** is actually loaded before making the the call.
+ */
foo ();
}
/* Replacing one overlay with another one can only happen from the main
- * program. This implies that an overlay can never load another overlay.
- */
+ ** program. This implies that an overlay can never load another overlay.
+ */
if (loadoverlay (2)) {
log ("Calling overlay 2 from main");
bar ();
foobar ();
}
- log ("Press any key...");
- cgetc ();
+ if (doesclrscrafterexit ()) {
+ log ("Press any key...");
+ getchar ();
+ }
}
projects / cc65 / blobdiff