Use cbm_load() to load overlays on CBMs.

cfg/c128-overlay.cfg

@@ -1,6 +1,7 @@
 SYMBOLS {
     __LOADADDR__:    type = import;
     __EXEHDR__:      type = import;
+    __OVERLAYADDR__: type = import;
     __STACKSIZE__:   type = weak, value = $0800; # 2k stack
     __OVERLAYSIZE__: type = weak, value = $1000; # 4k overlay
 }
@@ -9,14 +10,23 @@ MEMORY {
     LOADADDR: file = %O,               start = $1BFF,                   size = $0002;
     HEADER:   file = %O,               start = $1C01,                   size = $000C;
     RAM:      file = %O, define = yes, start = $1C0D,                   size = $A3F3 - __OVERLAYSIZE__ - __STACKSIZE__;
+    OVL1ADDR: file = "%O.1",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL1:     file = "%O.1",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL2ADDR: file = "%O.2",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL2:     file = "%O.2",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL3ADDR: file = "%O.3",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL3:     file = "%O.3",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL4ADDR: file = "%O.4",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL4:     file = "%O.4",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL5ADDR: file = "%O.5",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL5:     file = "%O.5",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL6ADDR: file = "%O.6",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL6:     file = "%O.6",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL7ADDR: file = "%O.7",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL7:     file = "%O.7",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL8ADDR: file = "%O.8",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL8:     file = "%O.8",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL9ADDR: file = "%O.9",           start = $BFFE - __OVERLAYSIZE__, size = $0002;
     OVL9:     file = "%O.9",           start = $C000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
 }
 SEGMENTS {
@@ -31,14 +41,23 @@ SEGMENTS {
     ZPSAVE:   load = RAM,      type = bss;
     BSS:      load = RAM,      type = bss, define = yes;
     ZEROPAGE: load = ZP,       type = zp;
+    OVL1ADDR: load = OVL1ADDR, type = ro;
     OVERLAY1: load = OVL1,     type = ro,  define = yes, optional = yes;
+    OVL2ADDR: load = OVL2ADDR, type = ro;
     OVERLAY2: load = OVL2,     type = ro,  define = yes, optional = yes;
+    OVL3ADDR: load = OVL3ADDR, type = ro;
     OVERLAY3: load = OVL3,     type = ro,  define = yes, optional = yes;
+    OVL4ADDR: load = OVL4ADDR, type = ro;
     OVERLAY4: load = OVL4,     type = ro,  define = yes, optional = yes;
+    OVL5ADDR: load = OVL5ADDR, type = ro;
     OVERLAY5: load = OVL5,     type = ro,  define = yes, optional = yes;
+    OVL6ADDR: load = OVL6ADDR, type = ro;
     OVERLAY6: load = OVL6,     type = ro,  define = yes, optional = yes;
+    OVL7ADDR: load = OVL7ADDR, type = ro;
     OVERLAY7: load = OVL7,     type = ro,  define = yes, optional = yes;
+    OVL8ADDR: load = OVL8ADDR, type = ro;
     OVERLAY8: load = OVL8,     type = ro,  define = yes, optional = yes;
+    OVL9ADDR: load = OVL9ADDR, type = ro;
     OVERLAY9: load = OVL9,     type = ro,  define = yes, optional = yes;
 }
 FEATURES {

cfg/c64-overlay.cfg

@@ -1,6 +1,7 @@
 SYMBOLS {
     __LOADADDR__:    type = import;
     __EXEHDR__:      type = import;
+    __OVERLAYADDR__: type = import;
     __STACKSIZE__:   type = weak, value = $0800; # 2k stack
     __OVERLAYSIZE__: type = weak, value = $1000; # 4k overlay
 }
@@ -9,14 +10,23 @@ MEMORY {
     LOADADDR: file = %O,               start = $07FF,                   size = $0002;
     HEADER:   file = %O,               start = $0801,                   size = $000C;
     RAM:      file = %O, define = yes, start = $080D,                   size = $C7F3 - __OVERLAYSIZE__ - __STACKSIZE__;
+    OVL1ADDR: file = "%O.1",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL1:     file = "%O.1",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL2ADDR: file = "%O.2",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL2:     file = "%O.2",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL3ADDR: file = "%O.3",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL3:     file = "%O.3",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL4ADDR: file = "%O.4",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL4:     file = "%O.4",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL5ADDR: file = "%O.5",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL5:     file = "%O.5",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL6ADDR: file = "%O.6",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL6:     file = "%O.6",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL7ADDR: file = "%O.7",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL7:     file = "%O.7",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL8ADDR: file = "%O.8",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL8:     file = "%O.8",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
+    OVL9ADDR: file = "%O.9",           start = $CFFE - __OVERLAYSIZE__, size = $0002;
     OVL9:     file = "%O.9",           start = $D000 - __OVERLAYSIZE__, size = __OVERLAYSIZE__;
 }
 SEGMENTS {
@@ -31,14 +41,23 @@ SEGMENTS {
     ZPSAVE:   load = RAM,      type = bss;
     BSS:      load = RAM,      type = bss, define = yes;
     ZEROPAGE: load = ZP,       type = zp;
+    OVL1ADDR: load = OVL1ADDR, type = ro;
     OVERLAY1: load = OVL1,     type = ro,  define = yes, optional = yes;
+    OVL2ADDR: load = OVL2ADDR, type = ro;
     OVERLAY2: load = OVL2,     type = ro,  define = yes, optional = yes;
+    OVL3ADDR: load = OVL3ADDR, type = ro;
     OVERLAY3: load = OVL3,     type = ro,  define = yes, optional = yes;
+    OVL4ADDR: load = OVL4ADDR, type = ro;
     OVERLAY4: load = OVL4,     type = ro,  define = yes, optional = yes;
+    OVL5ADDR: load = OVL5ADDR, type = ro;
     OVERLAY5: load = OVL5,     type = ro,  define = yes, optional = yes;
+    OVL6ADDR: load = OVL6ADDR, type = ro;
     OVERLAY6: load = OVL6,     type = ro,  define = yes, optional = yes;
+    OVL7ADDR: load = OVL7ADDR, type = ro;
     OVERLAY7: load = OVL7,     type = ro,  define = yes, optional = yes;
+    OVL8ADDR: load = OVL8ADDR, type = ro;
     OVERLAY8: load = OVL8,     type = ro,  define = yes, optional = yes;
+    OVL9ADDR: load = OVL9ADDR, type = ro;
     OVERLAY9: load = OVL9,     type = ro,  define = yes, optional = yes;
 }
 FEATURES {

libsrc/cbm/overlayaddr.s

@@ -0,0 +1,47 @@
+;
+; Oliver Schmidt, 2013-05-28
+;
+; This module supplies the load addresses that are expected by Commodore
+; machines in the first two bytes of overlay disk files.
+;
+
+
+        ; The following symbol is used by linker config to force the module
+        ; to get included into the output file
+        .export         __OVERLAYADDR__: absolute = 1
+
+.segment        "OVL1ADDR"
+
+        .addr   *+2
+
+.segment        "OVL2ADDR"
+
+        .addr   *+2
+
+.segment        "OVL3ADDR"
+
+        .addr   *+2
+
+.segment        "OVL4ADDR"
+
+        .addr   *+2
+
+.segment        "OVL5ADDR"
+
+        .addr   *+2
+
+.segment        "OVL6ADDR"
+
+        .addr   *+2
+
+.segment        "OVL7ADDR"
+
+        .addr   *+2
+
+.segment        "OVL8ADDR"
+
+        .addr   *+2
+
+.segment        "OVL9ADDR"
+
+        .addr   *+2

samples/multidemo.c

@@ -8,13 +8,17 @@
 
 
 #include <string.h>
+#include <conio.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <em.h>
+#ifndef __CBM__
 #include <fcntl.h>
 #include <unistd.h>
-#include <dirent.h>
+#else
-#include <stdlib.h>
+#include <device.h>
-#include <em.h>
+#endif
-#include <conio.h>
 
 
 /* The symbols _OVERLAY?_LOAD__ and _OVERLAY?_SIZE__ were generated by the
@@ -24,7 +28,6 @@
 extern void _OVERLAY1_LOAD__[], _OVERLAY1_SIZE__[];
 extern void _OVERLAY2_LOAD__[], _OVERLAY2_SIZE__[];
 extern void _OVERLAY3_LOAD__[], _OVERLAY3_SIZE__[];
-extern void _OVERLAY4_LOAD__[], _OVERLAY4_SIZE__[];
 
 struct {
     char     *name;
@@ -34,14 +37,7 @@ struct {
 } 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.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
 
 
 
@@ -94,8 +90,6 @@ void foobar (void)
 #pragma code-name(pop);
 
 
-#pragma code-name (push, "OVERLAY4");
-
 unsigned char loademdriver (void)
 {
     DIR *dir;
@@ -148,59 +142,12 @@ unsigned char loademdriver (void)
     return 0;
 }
 
-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 ();
-        }
-
-        printf ("Dbg: Stored overlay %u in pages %u-%u\n",
-                num + 1, overlay[num].page, page - 1);
-
-        close (file);
-    }
-}
-
-#pragma code-name(pop);
-
 
 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);
@@ -212,6 +159,15 @@ unsigned char loadoverlay (unsigned char 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;
@@ -226,9 +182,41 @@ unsigned char loadoverlay (unsigned char num)
     }
 }
 
+
+void copyoverlays (void)
+{
+    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 (&copyinfo);
+
+        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)
 {
-    if (loadoverlay (4)) {
     log ("Loading extended memory driver");
     if (loademdriver ()) {
         log ("Copying overlays into ext. memory");
@@ -236,7 +224,6 @@ void main (void)
     } else {
         log ("No extended memory driver found");
     }
-    }
 
     log ("Press any key...");
     cgetc ();

samples/overlaydemo.c

@@ -9,8 +9,12 @@
 
 #include <stdio.h>
 #include <conio.h>
+#ifndef __CBM__
 #include <fcntl.h>
 #include <unistd.h>
+#else
+#include <device.h>
+#endif
 
 
 extern void _OVERLAY1_LOAD__[], _OVERLAY1_SIZE__[];
@@ -69,14 +73,26 @@ void foobar (void)
 
 unsigned char loadfile (char *name, void *addr, void *size)
 {
+#ifndef __CBM__
+
     int file = open (name, O_RDONLY);
     if (file == -1) {
         log ("Opening overlay file failed");
         return 0;
     }
-
     read (file, addr, (unsigned) size);
     close (file);
+
+#else
+
+    /* Avoid compiler warnings about unused parameters. */
+    (void) addr; (void) size;
+    if (cbm_load (name, getcurrentdevice (), NULL) == 0) {
+        log ("Loading overlay file failed");
+        return 0;
+    }
+
+#endif
     return 1;
 }