Simplify ROM loading by providing utility function.

examples/min3.c

@@ -12,13 +12,10 @@ int main(void)
 {
 	uint8_t a, b, c;
 	uint8_t min;
-	bus_t bus;
+
 	rk65c02emu_t e;
 
-	bus = bus_init_with_default_devs();
-	e = rk65c02_init(&bus);
-
-	bus_load_file(e.bus, load_addr, "min3.rom");
+	e = rk65c02_load_rom("min3.rom", load_addr, NULL);
 
 	e.regs.SP = 0xFF;
 	e.regs.PC = load_addr;
@@ -29,6 +26,7 @@ int main(void)
 	stack_push(&e, c);
 
 	rk65c02_start(&e);
+
 	min = stack_pop(&e);
 	printf("Min is: %d\n", min);
 }

src/rk65c02.c

@@ -18,6 +18,30 @@
 
 void rk65c02_exec(rk65c02emu_t *);
 
+/**
+ * \brief Prep the emulator, load code from file, pass bus config optionally.
+ * \param path Path to ROM file to be loaded.
+ * \param load_addr Address on the bus where ROM should be loaded.
+ * \param b Pre-existing bus configuration, pass NULL if default requested.
+ */
+rk65c02emu_t
+rk65c02_load_rom(const char *path, uint16_t load_addr, bus_t *b)
+{
+	rk65c02emu_t e;
+
+	if (b == NULL) {
+		b = GC_MALLOC(sizeof(bus_t));
+		*b = bus_init_with_default_devs();
+	}
+
+	/* XXX: normal error handling instead of assert would be preferred */
+	assert(bus_load_file(b, load_addr, path));
+
+	e = rk65c02_init(b);
+
+	return e;
+}
+
 /*
  * Prepare the emulator for use, set initial CPU state.
  */

src/rk65c02.h

@@ -84,6 +84,7 @@ void rk65c02_dump_regs(reg_state_t);
 void rk65c02_dump_stack(rk65c02emu_t *, uint8_t);
 void rk65c02_irq(rk65c02emu_t *);
 void rk65c02_panic(rk65c02emu_t *, const char*, ...);
+rk65c02emu_t rk65c02_load_rom(const char *, uint16_t, bus_t *);
 
 #endif