Commit c20e1117 authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: add kernel ABI selection to Kconfig 



Add choice to use default or call0 ABI for the kernel code. If call0 ABI
is chosen add '-mabi=call0' to the flags. The toolchain support for this
option is rather new so only enable it when the compiler supports it.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 19c5699f

arch/xtensa/Kconfig

+35 −0
Original line number Diff line number Diff line
@@ -92,6 +92,9 @@ config CPU_BIG_ENDIAN 
config CPU_LITTLE_ENDIAN

	def_bool !CPU_BIG_ENDIAN



config CC_HAVE_CALL0_ABI

	def_bool $(success,test "$(shell,echo __XTENSA_CALL0_ABI__ | $(CC) -mabi=call0 -E -P - 2>/dev/null)" = 1)



menu "Processor type and features"



choice
@@ -250,6 +253,38 @@ config FAST_SYSCALL_SPILL_REGISTERS 


	  If unsure, say N.



choice

	prompt "Kernel ABI"

	default KERNEL_ABI_DEFAULT

	help

	  Select ABI for the kernel code. This ABI is independent of the

	  supported userspace ABI and any combination of the

	  kernel/userspace ABI is possible and should work.



	  In case both kernel and userspace support only call0 ABI

	  all register windows support code will be omitted from the

	  build.



	  If unsure, choose the default ABI.



config KERNEL_ABI_DEFAULT

	bool "Default ABI"

	help

	  Select this option to compile kernel code with the default ABI

	  selected for the toolchain.

	  Normally cores with windowed registers option use windowed ABI and

	  cores without it use call0 ABI.



config KERNEL_ABI_CALL0

	bool "Call0 ABI" if CC_HAVE_CALL0_ABI

	help

	  Select this option to compile kernel code with call0 ABI even with

	  toolchain that defaults to windowed ABI.

	  When this option is not selected the default toolchain ABI will

	  be used for the kernel code.



endchoice



config USER_ABI_CALL0

	bool

arch/xtensa/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -35,6 +35,10 @@ KBUILD_CFLAGS += -ffreestanding -D__linux__ 
KBUILD_CFLAGS += -pipe -mlongcalls -mtext-section-literals

KBUILD_CFLAGS += $(call cc-option,-mforce-no-pic,)

KBUILD_CFLAGS += $(call cc-option,-mno-serialize-volatile,)

ifneq ($(CONFIG_KERNEL_ABI_CALL0),)

KBUILD_CFLAGS += -mabi=call0

KBUILD_AFLAGS += -mabi=call0

endif



KBUILD_AFLAGS += -mlongcalls -mtext-section-literals