diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
new file mode 100644
index 0000000..cf30a39
--- /dev/null
+++ b/arch/um/os-Linux/time.c
@@ -0,0 +1,21 @@
+#include <stdlib.h>
+#include <sys/time.h>
+
+unsigned long long os_usecs(void)
+{
+	struct timeval tv;
+
+	gettimeofday(&tv, NULL);
+	return((unsigned long long) tv.tv_sec * 1000000 + tv.tv_usec);
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */