u-boot: build with gcc 5.2.0

packages/tools/u-boot/patches/u-boot-003-gcc5-no-unalligned-access.patch

@@ -0,0 +1,19 @@
+from https://raw.githubusercontent.com/schnitzeltony/meta-gumstix-community/master/recipes-bsp/u-boot/u-boot-overo/0013-arm-Switch-to-mno-unaligned-access-when-supported-by.patch
+
+--- a/arch/arm/cpu/armv7/config.mk	2015-11-22 20:44:42.744557427 +0100
++++ b/arch/arm/cpu/armv7/config.mk	2015-11-22 20:45:26.381024395 +0100
+@@ -18,9 +18,12 @@ PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_ARMV7
+ PF_RELFLAGS_SLB_AT := $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))
+ PLATFORM_RELFLAGS += $(PF_RELFLAGS_SLB_AT)
+
+-# SEE README.arm-unaligned-accesses
++# On supported platforms we set the bit which causes us to trap on unaligned
++# memory access.  This is the opposite of what the compiler expects to be
++# the default so we must pass in -mno-unaligned-access so that it is aware
++# of our decision.
+ PF_NO_UNALIGNED := $(call cc-option, -mno-unaligned-access,)
+-PLATFORM_NO_UNALIGNED := $(PF_NO_UNALIGNED)
++PLATFORM_CPPFLAGS += $(PF_NO_UNALIGNED)
+
+ ifneq ($(CONFIG_IMX_CONFIG),)
+ ifdef CONFIG_SPL