On 09:56 Tue 28 Feb , Sascha Hauer wrote:
> This shrinks the resulting binary size by ~25%. Exceptions
> are still handled in arm mode, so we have to explicitely
> put .arm directives into the exception code. Thumb-2 mode
> has been tested on i.MX51 Babbage board.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> ---
> arch/arm/Kconfig | 12 ++++++++++++
> arch/arm/Makefile | 11 +++++++++--
> arch/arm/cpu/cpu.c | 27 +++++++++++++++++++++++++++
> arch/arm/cpu/exceptions.S | 1 +
> arch/arm/cpu/start.c | 26 ++++++++++++++++++--------
> arch/arm/include/asm/barebox-arm-head.h | 12 ++++++++++++
> arch/arm/include/asm/unified.h | 8 ++++----
> arch/arm/lib/armlinux.c | 17 ++++++++++++++++-
> commands/go.c | 6 +++++-
> common/misc.c | 3 +++
> include/common.h | 6 ++++++
> 11 files changed, 113 insertions(+), 16 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 4c0ee58..adb020a 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -101,6 +101,18 @@ config AEABI
>
> To use this you need GCC version 4.0.0 or later.
>
> +config THUMB2_BAREBOX
> + select ARM_ASM_UNIFIED
> + depends on CPU_V7
> + bool "Compile barebox in thumb-2 mode (read help)"
> + help
> + This enables compilation of barebox in thumb-2 mode which generates
> + ~25% smaller binaries. Arm Assembly code needs some fixups to be able
> + to work correctly in thumb-2 mode. the barebox core should have these
> + fixups since most assembly code is derived from the Kernel. However,
> + your board lowlevel init code may break in thumb-2 mode. You have been
> + warned.
> +
> endmenu
>
> menu "Arm specific settings "
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 9926280..56f21ab 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -39,8 +39,15 @@ ifeq ($(CONFIG_ARM_UNWIND),y)
> CFLAGS_ABI +=-funwind-tables
> endif
>
> -CPPFLAGS += $(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float
> -AFLAGS += -include asm/unified.h -msoft-float
> +ifeq ($(CONFIG_THUMB2_BAREBOX),y)
> +AFLAGS_AUTOIT :=$(call as-option,-Wa$(comma)-mimplicit-it=always,-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
> +
> +CPPFLAGS += $(CFLAGS_ABI) $(arch-y) $(tune-y) -msoft-float $(CFLAGS_THUMB2)
> +AFLAGS += -include asm/unified.h -msoft-float $(AFLAGS_THUMB2)
>
> # Machine directory name. This list is sorted alphanumerically
> # by CONFIG_* macro name.
> diff --git a/arch/arm/cpu/cpu.c b/arch/arm/cpu/cpu.c
> index cf31e8b..71ef8c0 100644
> --- a/arch/arm/cpu/cpu.c
> +++ b/arch/arm/cpu/cpu.c
> @@ -26,6 +26,7 @@
> */
>
> #include <common.h>
> +#include <init.h>
> #include <command.h>
> #include <cache.h>
> #include <asm/mmu.h>
> @@ -89,3 +90,29 @@ void arch_shutdown(void)
> );
> #endif
> }
> +
> +#ifdef CONFIG_THUMB2_BAREBOX
> +static void thumb2_execute(void *func, int argc, char *argv[])
> +{
> + /*
> + * Switch back to arm mode before executing external
> + * programs.
> + */
> + __asm__ __volatile__ (
> + "mov r0, #0\n"
> + "mov r1, %0\n"
> + "mov r2, %1\n"
> + "bx %2\n"
> + :
> + : "r" (argc - 1), "r" (&argv[1]), "r" (func)
> + : "r0", "r1", "r2"
> + );
> +}
> +
> +static int execute_init(void)
> +{
> + do_execute = thumb2_execute;
> + return 0;
> +}
> +postcore_initcall(execute_init);
> +#endif
> diff --git a/arch/arm/cpu/exceptions.S b/arch/arm/cpu/exceptions.S
> index 6f35d40..c08537a 100644
> --- a/arch/arm/cpu/exceptions.S
> +++ b/arch/arm/cpu/exceptions.S
> @@ -106,6 +106,7 @@ _STACK_START:
> * exception handlers
> */
> .section ".text","ax"
> + .arm
>
> .align 5
> .globl undefined_instruction
> diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
> index 89aff1d..5011fa2 100644
> --- a/arch/arm/cpu/start.c
> +++ b/arch/arm/cpu/start.c
> @@ -33,26 +33,36 @@ void __naked __section(.text_entry) start(void)
> barebox_arm_head();
> }
>
> +#ifdef CONFIG_THUMB2_BAREBOX
> +#define STOP \
> + "1: bne 1b\n" \
> + "nop\n"
> +#else
> +#define STOP \
> + "1: bne 1b\n"
> +#endif
here is my issue can not use bne
can only use ldr or b
Best Regards,
J.
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