Add breakpoints.

src/Makefile

@@ -1,7 +1,7 @@
 CLI=rk65c02cli
 CLI_OBJS=rk65c02cli.o
 
-LIB_OBJS=rk65c02.o bus.o instruction.o emulation.o
+LIB_OBJS=rk65c02.o bus.o instruction.o emulation.o debug.o
 LIB_SO=librk65c02.so
 LIB_STATIC=librk65c02.a
 
@@ -11,6 +11,7 @@ CFLAGS=-Wall -fpic -ggdb
 
 65C02ISA=65c02isa
 EMULATION=emulation
+# TODO: better include handling
 
 all : $(LIB_SO) $(LIB_STATIC) $(CLI)
 

src/debug.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <utlist.h>
+
+#include "rk65c02.h"
+#include "debug.h"
+
+bool
+debug_breakpoint_remove(rk65c02emu_t *e, uint16_t address)
+{
+	breakpoint_t *bp, *tmp;
+
+	if (e->bps_head == NULL)
+		return false;
+
+	LL_FOREACH_SAFE(e->bps_head, bp, tmp) {
+		if (bp->address == address) {
+			LL_DELETE(e->bps_head, bp);
+			return true;
+		}
+	}
+
+	return false;
+}
+
+bool
+debug_breakpoint_add(rk65c02emu_t *e, uint16_t address)
+{
+	breakpoint_t *bp;
+
+	bp = (breakpoint_t *) malloc(sizeof(breakpoint_t));
+	bp->address = address;
+
+	LL_APPEND((e->bps_head), bp);
+
+	return true;
+}
+
+bool
+debug_PC_is_breakpoint(rk65c02emu_t *e)
+{
+	breakpoint_t *bp;
+
+	if (e->bps_head == NULL)
+		return false;
+
+	LL_FOREACH(e->bps_head, bp) {
+		if (bp->address == e->regs.PC)
+			return true;
+	}
+
+
+	return false;
+}

src/debug.h

@@ -0,0 +1,12 @@
+#ifndef _DEBUG_H_
+#define _DEBUG_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "rk65c02.h" 
+
+bool debug_PC_is_breakpoint(rk65c02emu_t *);
+bool debug_breakpoint_add(rk65c02emu_t *, uint16_t);
+#endif /* _DEBUG_H_ */
+

src/rk65c02.c

@@ -9,6 +9,7 @@
 #include "bus.h"
 #include "instruction.h"
 #include "rk65c02.h"
+#include "debug.h"
 
 void rk65c02_exec(rk65c02emu_t *);
 
@@ -29,6 +30,8 @@ rk65c02_init(bus_t *b)
 
 	e.irq = false;
 
+	e.bps_head = NULL;
+
 	return e;
 }
 
@@ -89,7 +92,11 @@ rk65c02_exec(rk65c02emu_t *e)
 	if (e->irq && (!(e->regs.P & P_IRQ_DISABLE)))
 		rk65c02_irq(e);
 
-	/* XXX: handle breakpoints and watch points */
+	/* XXX: handle watchpoints toos */
+	if (debug_PC_is_breakpoint(e)) {
+		e->state = STOPPED;
+		e->stopreason = BREAKPOINT;
+	}
 
 	/* if disassembly-when-running enabled */
 	disassemble(e->bus, e->regs.PC);

src/rk65c02.h

@@ -29,6 +29,8 @@ struct reg_state {
 	uint8_t P;      /* status */
 };
 
+typedef struct reg_state reg_state_t;
+
 #define P_CARRY 0x1
 #define P_ZERO 0x2
 #define P_IRQ_DISABLE 0x4
@@ -47,7 +49,10 @@ struct reg_state {
 
 #define BIT(val,n) ((val) & (1 << (n)))
 
-typedef struct reg_state reg_state_t;
+typedef struct breakpoint_t {
+	uint16_t address;
+	struct breakpoint_t *next;
+} breakpoint_t;
 
 struct rk65c02emu {
 	emu_state_t state;
@@ -55,6 +60,8 @@ struct rk65c02emu {
 	reg_state_t regs;
 	emu_stop_reason_t stopreason;
 	bool irq;	/* interrupt request line state, true is asserted */
+
+	breakpoint_t *bps_head;	/* pointer to linked list with breakpoints  */
 };
 
 typedef struct rk65c02emu rk65c02emu_t;