@@ -417,11 +417,13 @@
 
 	process_load_queue();
 }
 
 Class
-objc_allocateClassPair(Class superclass, const char *name, size_t extra_bytes)
+objc_allocateClassPair(Class superclass OBJC_M68K_REG("a0"),
+    const char *name OBJC_M68K_REG("a1"),
+    size_t extra_bytes OBJC_M68K_REG("d0"))
 {
 	struct objc_class *cls, *metaclass;
 	Class iter, rootclass = Nil;
 
 	if (extra_bytes > LONG_MAX)
@@ -451,11 +453,11 @@
 
 	return cls;
 }
 
 void
-objc_registerClassPair(Class cls)
+objc_registerClassPair(Class cls OBJC_M68K_REG("a0"))
 {
 	objc_global_mutex_lock();
 
 	register_class((struct objc_abi_class *)cls);
 
@@ -528,11 +530,12 @@
 {
 	return objc_getRequiredClass(name);
 }
 
 unsigned int
-objc_getClassList(Class *buf, unsigned int count)
+objc_getClassList(Class *buf OBJC_M68K_REG("a0"),
+    unsigned int count OBJC_M68K_REG("d0"))
 {
 	unsigned int j;
 	objc_global_mutex_lock();
 
 	if (buf == NULL)
@@ -568,11 +571,11 @@
 
 	return j;
 }
 
 Class *
-objc_copyClassList(unsigned int *len)
+objc_copyClassList(unsigned int *len OBJC_M68K_REG("a0"))
 {
 	Class *ret;
 	unsigned int count;
 
 	objc_global_mutex_lock();
@@ -592,47 +595,48 @@
 
 	return ret;
 }
 
 bool
-class_isMetaClass(Class cls)
+class_isMetaClass(Class cls OBJC_M68K_REG("a0"))
 {
 	if (cls == Nil)
 		return false;
 
 	return (cls->info & OBJC_CLASS_INFO_METACLASS);
 }
 
 const char *
-class_getName(Class cls)
+class_getName(Class cls OBJC_M68K_REG("a0"))
 {
 	if (cls == Nil)
 		return "";
 
 	return cls->name;
 }
 
 Class
-class_getSuperclass(Class cls)
+class_getSuperclass(Class cls OBJC_M68K_REG("a0"))
 {
 	if (cls == Nil)
 		return Nil;
 
 	return cls->superclass;
 }
 
 unsigned long
-class_getInstanceSize(Class cls)
+class_getInstanceSize(Class cls OBJC_M68K_REG("a0"))
 {
 	if (cls == Nil)
 		return 0;
 
 	return cls->instance_size;
 }
 
 IMP
-class_getMethodImplementation(Class cls, SEL sel)
+class_getMethodImplementation(Class cls OBJC_M68K_REG("a0"),
+    SEL sel OBJC_M68K_REG("a1"))
 {
 	/*
 	 * We use a dummy object here so that the normal lookup is used, even
 	 * though we don't have an object. Doing so is safe, as objc_msg_lookup
 	 * does not access the object, but only its class.
@@ -652,11 +656,12 @@
 	dummy.isa = cls;
 	return objc_msg_lookup((id)&dummy, sel);
 }
 
 IMP
-class_getMethodImplementation_stret(Class cls, SEL sel)
+class_getMethodImplementation_stret(Class cls OBJC_M68K_REG("a0"),
+    SEL sel OBJC_M68K_REG("a1"))
 {
 	/*
 	 * Same as above, but use objc_msg_lookup_stret instead, so that the
 	 * correct forwarding handler is returned.
 	 */
@@ -719,11 +724,12 @@
 
 	objc_update_dtable(cls);
 }
 
 const char *
-class_getMethodTypeEncoding(Class cls, SEL sel)
+class_getMethodTypeEncoding(Class cls OBJC_M68K_REG("a0"),
+    SEL sel OBJC_M68K_REG("a1"))
 {
 	struct objc_method *method;
 
 	if (cls == Nil)
 		return NULL;
@@ -743,11 +749,12 @@
 
 	return NULL;
 }
 
 bool
-class_addMethod(Class cls, SEL sel, IMP imp, const char *types)
+class_addMethod(Class cls OBJC_M68K_REG("a0"), SEL sel OBJC_M68K_REG("a1"),
+    IMP imp OBJC_M68K_REG("a2"), const char *types OBJC_M68K_REG("a3"))
 {
 	bool ret;
 
 	objc_global_mutex_lock();
 
@@ -761,11 +768,12 @@
 
 	return ret;
 }
 
 IMP
-class_replaceMethod(Class cls, SEL sel, IMP newimp, const char *types)
+class_replaceMethod(Class cls OBJC_M68K_REG("a0"), SEL sel OBJC_M68K_REG("a1"),
+    IMP newimp OBJC_M68K_REG("a2"), const char *types OBJC_M68K_REG("a3"))
 {
 	struct objc_method *method;
 	IMP oldimp;
 
 	objc_global_mutex_lock();
@@ -783,11 +791,11 @@
 
 	return oldimp;
 }
 
 Class
-object_getClass(id obj_)
+object_getClass(id obj_ OBJC_M68K_REG("a0"))
 {
 	struct objc_object *obj;
 
 	if (obj_ == nil)
 		return Nil;
@@ -796,11 +804,11 @@
 
 	return obj->isa;
 }
 
 Class
-object_setClass(id obj_, Class cls)
+object_setClass(id obj_ OBJC_M68K_REG("a0"), Class cls OBJC_M68K_REG("a1"))
 {
 	struct objc_object *obj;
 	Class old;
 
 	if (obj_ == nil)
@@ -813,11 +821,11 @@
 
 	return old;
 }
 
 const char *
-object_getClassName(id obj)
+object_getClassName(id obj OBJC_M68K_REG("a0"))
 {
 	return class_getName(object_getClass(obj));
 }
 
 static void