diff --git a/bootloader/common.c b/bootloader/common.c
index 07dd8120ed..705441357a 100644
--- a/bootloader/common.c
+++ b/bootloader/common.c
@@ -165,3 +165,17 @@ int load_raw_firmware(unsigned char* buf, char* firmware, int buffer_size)
     close(fd);
     return len;
 }
+
+#if (!defined(MISC_H) && CONFIG_PLATFORM & PLATFORM_HOSTED)
+/* open but with a builtin printf for assembling the path */
+int open_pathfmt(char *buf, size_t size, int oflag, const char *pathfmt, ...)
+{
+    va_list ap;
+    va_start(ap, pathfmt);
+    vsnprintf(buf, size, pathfmt, ap);
+    va_end(ap);
+    if ((oflag & O_PATH) == O_PATH)
+        return -1;
+    return open(buf, oflag, 0666);
+}
+#endif