Added C64/C128 SuperCPU accelerator functions and started on a generic framework for accelerators.

libsrc/c128/acc_detect_scpu.s

@@ -0,0 +1,34 @@
+;
+; Marco van den Heuvel, 2018-04-08
+;
+
+; unsigned char detect_scpu (void);
+;
+;/* Check for the presence of the SuperCPU cartridge.
+; *
+; * Possible return values:
+; * 0x00  : SuperCPU cartridge not present
+; * 0x01  : SuperCPU cartridge present
+; */
+
+        .export         _detect_scpu
+
+        .include        "accelerator.inc"
+_detect_scpu:
+        ldx     #$00
+        txa
+
+; Make sure the current CPU is a 65816
+        clc
+        .byte   $E2,$01                ; NOP #$01 on 6510 and 65(S)C02, LDA $(01,S),Y on 65CE02 and 4510, SEP #$01 on 65816
+        bcc     not_found              ; carry will be set on 65816
+
+; 65816 has been detected, make sure it's the SuperCPU cartridge
+
+        lda     SuperCPU_Detect
+        asl
+        bcs     not_found
+found:
+        lda     #$01
+not_found:
+        rts