got some of the pty actually working in userspace

rocklibc/src/syscall.c

@@ -28,7 +28,7 @@ void exit(int status) {
 }
 
 int open(const char* path) {
-    return syscall1(SYS_OPEN, (uint32_t)path);
+    return syscall3(SYS_OPEN, (uint32_t)path, 0, 0);
 }
 
 int write(int fd, const void* buf, size_t cnt) {