Thumb-2: Add Thumb-2 support to the build files
This patch adds the necessary entries to the Makefile and Kconfig
files for building the Thumb-2 kernel.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index da28e7b..a36b5a8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -983,6 +983,18 @@
default AT91_TIMER_HZ if ARCH_AT91
default 100
+config THUMB2_KERNEL
+ bool "Compile the kernel in Thumb-2 mode"
+ depends on CPU_V7 && EXPERIMENTAL
+ select AEABI
+ select ARM_ASM_UNIFIED
+ help
+ By enabling this option, the kernel will be compiled in
+ Thumb-2 mode. A compiler/assembler that understand the unified
+ ARM-Thumb syntax is needed.
+
+ If unsure, say N.
+
config ARM_ASM_UNIFIED
bool
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index a89e473..1a6f70e 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -8,6 +8,7 @@
# n, but then RMK will have to kill you ;).
config FRAME_POINTER
bool
+ depends on !THUMB2_KERNEL
default y if !ARM_UNWIND
help
If you say N here, the resulting kernel will be slightly smaller and
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 3505572..e150f23 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -93,9 +93,16 @@
CFLAGS_ABI +=-funwind-tables
endif
+ifeq ($(CONFIG_THUMB2_KERNEL),y)
+AFLAGS_AUTOIT :=$(call as-option,-Wa$(comma)-mimplicit-it=thumb,-Wa$(comma)-mauto-it)
+AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
+CFLAGS_THUMB2 :=-mthumb $(AFLAGS_AUTOIT) $(AFLAGS_NOWARN)
+AFLAGS_THUMB2 :=$(CFLAGS_THUMB2) -Wa$(comma)-mthumb
+endif
+
# Need -Uarm for gcc < 3.x
-KBUILD_CFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS +=$(CFLAGS_ABI) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_THUMB2) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
+KBUILD_AFLAGS +=$(CFLAGS_ABI) $(AFLAGS_THUMB2) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
CHECKFLAGS += -D__arm__