Update buidlroot to version 2016.08.1

bsp/buildroot/package/gcc/4.9.4/871-xtensa-reimplement-register-spilling.patch

@@ -0,0 +1,76 @@
+From 05154174b369505238b759cf80d595d8cfc8c731 Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Mon, 10 Aug 2015 21:35:20 +0300
+Subject: [PATCH 1/3] xtensa: reimplement register spilling
+
+Spilling windowed registers in userspace is much easier, more portable,
+less error-prone and equally effective as in kernel. Now that register
+spilling syscall is considered obsolete in the xtensa linux kernel
+replace it with CALL12 followed by series of ENTRY in libgcc.
+
+2015-08-18  Max Filippov  <jcmvbkbc@gmail.com>
+libgcc/
+	* config/xtensa/lib2funcs.S (__xtensa_libgcc_window_spill): Use
+	CALL12 followed by series of ENTRY to spill windowed registers.
+	(__xtensa_nonlocal_goto): Call __xtensa_libgcc_window_spill
+	instead of making linux spill syscall.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+Backported from: r226962
+
+ libgcc/config/xtensa/lib2funcs.S | 30 +++++++++++++++++++++++-------
+ 1 file changed, 23 insertions(+), 7 deletions(-)
+
+diff --git a/libgcc/config/xtensa/lib2funcs.S b/libgcc/config/xtensa/lib2funcs.S
+index 3ac8c1d..2e678af 100644
+--- a/libgcc/config/xtensa/lib2funcs.S
++++ b/libgcc/config/xtensa/lib2funcs.S
+@@ -33,10 +33,29 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+ 	.global	__xtensa_libgcc_window_spill
+ 	.type	__xtensa_libgcc_window_spill,@function
+ __xtensa_libgcc_window_spill:
+-	entry	sp, 32
+-	movi	a2, 0
+-	syscall
++	entry	sp, 48
++#if XCHAL_NUM_AREGS > 16
++	call12	1f
++	retw
++	.align	4
++1:
++	.rept	(XCHAL_NUM_AREGS - 24) / 12
++	_entry	sp, 48
++	mov	a12, a0
++	.endr
++	_entry	sp, 16
++#if XCHAL_NUM_AREGS % 12 == 0
++	mov	a4, a4
++#elif XCHAL_NUM_AREGS % 12 == 4
++	mov	a8, a8
++#elif XCHAL_NUM_AREGS % 12 == 8
++	mov	a12, a12
++#endif
++	retw
++#else
++	mov	a8, a8
+ 	retw
++#endif
+ 	.size	__xtensa_libgcc_window_spill, .-__xtensa_libgcc_window_spill
+ 
+ 
+@@ -58,10 +77,7 @@ __xtensa_nonlocal_goto:
+ 	entry	sp, 32
+ 
+ 	/* Flush registers.  */
+-	mov	a5, a2
+-	movi	a2, 0
+-	syscall
+-	mov	a2, a5
++	call8	__xtensa_libgcc_window_spill
+ 
+ 	/* Because the save area for a0-a3 is stored one frame below
+ 	   the one identified by a2, the only way to restore those
+-- 
+1.8.1.4
+