Add additional pass that writes values based on memory address

.gitignore

@@ -1,3 +1,3 @@
 emu6502
-*.o
+*.o65
 *.bin

Makefile

@@ -1,25 +1,25 @@
 
-.PHONY: all memtest-f000.901465.bin memtest-f000.901465.o ascii memtest-f000.901465+ascii.o emu5602
+.PHONY: all memtest-f000.901465.bin memtest-f000.901465.o65 ascii memtest-f000.901465+ascii.o65 emu5602
 
 all: memtest-f000.901465.bin ascii emu5602
 
 clean:
-	rm -f memtest-f000.901465.bin memtest-f000.901465.o
+	rm -f memtest-f000.901465.bin memtest-f000.901465.o65 memtest-f000.901465.map
-	rm -f memtest-f000.901465+ascii.bin memtest-f000.901465+ascii.o
+	rm -f memtest-f000.901465+ascii.bin memtest-f000.901465+ascii.o65 memtest-f000.901465+ascii.map
 	rm -f emu6502
 
-memtest-f000.901465.bin: memtest-f000.901465.o
+memtest-f000.901465.bin: memtest-f000.901465.o65
-	dd if=memtest-f000.901465.o bs=1 skip=2 of=memtest-f000.901465.bin
+	dd if=memtest-f000.901465.o65 bs=1 skip=2 of=memtest-f000.901465.bin
 
-memtest-f000.901465.o:
+memtest-f000.901465.o65:
-	xa -M -A F000 -O PETSCREEN -c -C -v -o memtest-f000.901465.o memtest-f000.901465.asm
+	xa -M -A F000 -O PETSCREEN -c -C -v -l memtest-f000.901465.map -o memtest-f000.901465.o65 memtest-f000.901465.asm
 
-ascii: memtest-f000.901465+ascii.o
+ascii: memtest-f000.901465+ascii.o65
-	dd if=memtest-f000.901465+ascii.o bs=1 skip=2 of=memtest-f000.901465+ascii.bin
+	dd if=memtest-f000.901465+ascii.o65 bs=1 skip=2 of=memtest-f000.901465+ascii.bin
 
-memtest-f000.901465+ascii.o:
+memtest-f000.901465+ascii.o65:
-	xa -M -A F000 -O ASCII -c -C -v -o memtest-f000.901465+ascii.o memtest-f000.901465.asm
+	xa -M '-D_MEMEND=$$1000' -A F000 -O ASCII -c -C -v -l memtest-f000.901465+ascii.map -o memtest-f000.901465+ascii.o65 memtest-f000.901465.asm
 
 
 emu5602:
-	gcc -o emu6502 emu6502.c fake6502.c
+	gcc -D_END=$$(cat memtest-f000.901465+ascii.map | grep ^done, | cut -d, -f2 | tr -d ' ,') -o emu6502 emu6502.c fake6502.c

emu6502.c

@@ -7,23 +7,28 @@
 #include <string.h>
 #include <sys/mman.h>
 
+#define RAMSIZE 0x1000
+
 extern uint32_t instructions;
 extern void reset6502(void);
 extern void step6502(void);
 
-uint8_t *ram, *screen, *a000, *b000, *c000, *d000, *e000, *f000;
+uint8_t *ram, *screen, *f000;
 
 
 uint8_t read6502(uint16_t address) {
-  if (address == 0xf27e) {
+  if (address == _END) {
     printf("DONE\n");
     exit(0);
   }
   uint8_t value = 0x00;
-  if (address < 0x4000) {
+  if (address < RAMSIZE) {
-    // emulate memory error in uppermost page
+    if (address >= RAMSIZE-16) {
-    if (address >= 0x3ff0) {
+      // emulate memory error in uppermost page
       value = ram[address] & 0xf7;
+    } else if (address >= 0x0100 && address <= 0x01ff) {
+      // simulate broken LSB in stack page
+      value = ram[address & 0xfffe];
     } else {
       value = ram[address];
     }
@@ -32,21 +37,6 @@ uint8_t read6502(uint16_t address) {
     // screen buffer is mirrored 4 times, discard upper 2 bytes
     value = screen[address & 0x03ff];
     printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
-  } else if (address >= 0xa000 && address <= 0xafff) {
-    value = a000[address-0xa000];
-    printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
-  } else if (address >= 0xb000 && address <= 0xbfff) {
-    value = b000[address-0xb000];
-    printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
-  } else if (address >= 0xc000 && address <= 0xcfff) {
-    value = c000[address-0xc000];
-    printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
-  } else if (address >= 0xd000 && address <= 0xdfff) {
-    value = d000[address-0xd000];
-    printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
-  } else if (address >= 0xe000 && address <= 0xe7ff) {
-    value = e000[address-0xe000];
-    printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
   } else if (address >= 0xf000) {
     value = f000[address-0xf000];
     printf("%08x: READ  %04x -> %02x\n", instructions, address, value);
@@ -57,10 +47,15 @@ uint8_t read6502(uint16_t address) {
 }
 
 void write6502(uint16_t address, uint8_t value) {
-  if (address < 0x4000) {
+  if (address < RAMSIZE) {
     printf("%08x: WRITE %04x <- %02x\n", instructions, address, value);
-    ram[address] = value;
+    // simulate broken LSB in stack page
-  } else if (address >= 0x800 && address <= 0x8fff) {
+    if (address >= 0x100 && address <= 0x1ff) {
+      ram[address & 0xfffe] = value;
+    } else {
+      ram[address] = value;
+    }
+  } else if (address >= 0x8000 && address <= 0x8fff) {
     printf("%08x: WRITE %04x <- %02x, SCREEN(%d,%d)\n", instructions, address, value, (address&0x03ff)%40, (address&0x03ff)/40);
     screen[address & 0x03ff] = value;
   } else {
@@ -69,20 +64,9 @@ void write6502(uint16_t address, uint8_t value) {
 }
 
 int main() {
-  ram = (uint8_t*) malloc(0x4000);
+  ram = (uint8_t*) malloc(RAMSIZE);
   screen = (uint8_t*) malloc(0x400);
   memset(screen, 'X', 0x400);
-  int afd = open("memtest-9000.901465.bin", O_RDONLY);
-  a000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, afd, 0);
-  int bfd = open("memtest-9000.901465.bin", O_RDONLY);
-  b000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, bfd, 0);
-  int cfd = open("basic-2-c000.901465-01.bin", O_RDONLY);
-  c000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, cfd, 0);
-  int dfd = open("basic-2-d000.901465-02.bin", O_RDONLY);
-  d000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, dfd, 0);
-  int efd = open("edit-2-n.901447-24.bin", O_RDONLY);
-  e000 = mmap(0, 0x0800, PROT_READ, MAP_PRIVATE, efd, 0);
-  //int ffd = open("kernal-2.901465-03.bin", O_RDONLY);
   int ffd = open("memtest-f000.901465+ascii.bin", O_RDONLY);
   f000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, ffd, 0);
 

memtest-f000.901465.asm

@@ -1,13 +1,18 @@
 
-	.word $f000
+#ifndef _MEMSTART
-	* = $f000
+#define _MEMSTART $0007
+#endif
+
+#ifndef _MEMEND
+#define _MEMEND $4000
+#endif
 
 	scrptr = $8000
 	eoscr = $83e7		; last screen address
 	lastline = $83c0	; start of last line
 
-	memstart = $0010
+	memstart = _MEMSTART
-	memend = $4000
+	memend = _MEMEND
 
 	addr = $0100
 	aoff = $02
@@ -15,6 +20,10 @@
 	pbyte = $04
 	scroff = $0605
 
+	
+	.word $f000
+	* = $f000
+
 main:
 	sei
 	;; clear screen
@@ -83,11 +92,23 @@ noskip:
 	sty eoscr-1
 	;; store pass value at the current address
 	lda pbyte
+	;; special case $42: was already written, read only and compare to address' (HI xor LO)
+	cmp #$42
+	beq special42
 	sta (<addr),Y
 	;; compare current address to $FF, "continue" if equal
 	cmp (<addr),Y
 	bne print
 	jmp loopend
+	
+special42:
+	;; compare value in address to (HI xor LO)
+	ldy aoff
+	tya
+	eor >addr
+	cmp (<addr),Y
+	bne print
+	jmp loopend
 
 print:	
 	;; memory content was not equal, print
@@ -371,31 +392,60 @@ passend:
 	ldy ipass
 	lda passbytes,Y
 	cmp #$7F
-	beq eot
+	bne passend2
+	jmp done
+passend2:	
 	iny
 	sty ipass
+	lda passbytes,Y
+	cmp #$42
+	beq fill
 	jmp pass
 
+	;; $42 is a special case meant to test proper adressing
+	;; fill value behind each address with (HI xor LO)
+fill:
+	ldx #>memstart
+	stx >addr
+	ldy #<memstart
+	sty aoff
+fillloop:
+	tya
+	eor >addr
+	sta (<addr),Y
+	iny
+	sty aoff
+	cpy #00
+	bne fillnocarry
+	inx
+fillnocarry:	
+	stx >addr
+	cpx #>memend
+	bne fillloop
+	jmp pass
+	
+
 	
 hexchars:
 	.asc "0123456789ABCDEF"
 passbytes:
-	.byt $FF, $00, $AA, $55, $01, $02, $04, $08, $10, $20, $40, $80, $FE, $FD, $FB, $F7, $EF, $DF, $BF, $7F
+	.byt $FF, $00, $AA, $55, $42, $01, $02, $04, $08, $10, $20, $40, $80, $FE, $FD, $FB, $F7, $EF, $DF, $BF, $7F
 passchars:
-	.asc "FF00AA550102040810204080FEFDFBF7EFDFBF7F"
+	.asc "FF00AA55XX0102040810204080FEFDFBF7EFDFBF7F"
 infotext:
-	.asc " = MOS6502 memtest 2022, s3lph ="
+	.asc " CBM 3001 memtest, 2022 s3lph.me"
+
+done:
+	;; done, loop forever
+	jmp done
+
 
 eot:
-	;; done, loop forever
-	jmp eot
-
-
 	;; Fill with FF
 	* = $fffa
-	.dsb (*-eot-3), $ff
+	.dsb (*-eot), $ff
 	;; 6502 vectors
 	* = $fffa
-	.byt <main, >main	; NMIV
+	.byt <done, >done	; NMIV
 	.byt <main, >main 	; RESV
 	.byt <main, >main 	; IRQV