This patch is for the ARM architecture. It fixes the correct handover of
the "--fix-v4bx" flag from gcc to the linker when the architecture
doesn't support the thumb "bx lr" instruction.

You'll also have to disable the USE_BX flag in the kernel configuration.

The "bx lr" instruction is used by default in newer gccs and needs to be
"fixed" by the linker or the assembler (see
http://wiki.debian.org/ArmEabiPort).

Signed-off-by: Sven Bachmann <dev at mcbachmann.de>

--- a/gcc/config/arm/bpabi.h
+++ b/gcc/config/arm/bpabi.h
@@ -57,6 +57,10 @@
 #undef  SUBTARGET_EXTRA_ASM_SPEC
 #define SUBTARGET_EXTRA_ASM_SPEC "%{mabi=apcs-gnu|mabi=atpcs:-meabi=gnu;:-meabi=5}" TARGET_FIX_V4BX_SPEC
 
+/* Tell the linker to build BPABI binaries.  */
+#undef  SUBSUBTARGET_EXTRA_LINK_SPEC
+#define SUBSUBTARGET_EXTRA_LINK_SPEC TARGET_FIX_V4BX_SPEC
+
 #ifndef SUBTARGET_EXTRA_LINK_SPEC
 #define SUBTARGET_EXTRA_LINK_SPEC ""
 #endif
--- a/gcc/config/arm/linux-eabi.h
+++ b/gcc/config/arm/linux-eabi.h
@@ -55,8 +55,15 @@
 #define TARGET_LINKER_EMULATION "armelf_linux_eabi"
 #endif
 
+/* Extra define to keep FIX_V4BX from bpabi.h if defined.  */
+#ifndef SUBSUBTARGET_EXTRA_LINK_SPEC
+#define SUBSUBTARGET_EXTRA_LINK_SPEC ""
+#endif
+ 
 #undef  SUBTARGET_EXTRA_LINK_SPEC
-#define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
+#define SUBTARGET_EXTRA_LINK_SPEC		\
+		" -m " TARGET_LINKER_EMULATION	\
+		SUBSUBTARGET_EXTRA_LINK_SPEC
 
 /* Use ld-linux.so.3 so that it will be possible to run "classic"
    GNU/Linux binaries on an EABI system.  */