[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/arch/sh/lib64/strlen.S b/src/kernel/linux/v4.14/arch/sh/lib64/strlen.S
new file mode 100644
index 0000000..c00b972
--- /dev/null
+++ b/src/kernel/linux/v4.14/arch/sh/lib64/strlen.S
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Simplistic strlen() implementation for SHmedia.
+ *
+ * Copyright (C) 2003  Paul Mundt <lethal@linux-sh.org>
+ */
+
+	.section .text..SHmedia32,"ax"
+	.globl	strlen
+	.type	strlen,@function
+
+	.balign 16
+strlen:
+	ptabs	r18, tr4
+
+	/*
+	 * Note: We could easily deal with the NULL case here with a simple
+	 * sanity check, though it seems that the behavior we want is to fault
+	 * in the event that r2 == NULL, so we don't bother.
+	 */
+/*	beqi    r2, 0, tr4 */	! Sanity check
+
+	movi	-1, r0
+	pta/l	loop, tr0
+loop:
+	ld.b	r2, 0, r1
+	addi	r2, 1, r2
+	addi	r0, 1, r0
+	bnei/l	r1, 0, tr0
+
+	or	r0, r63, r2
+	blink	tr4, r63
+
+	.size	strlen,.-strlen