[PATCH 1/1] ARM: compressed/head.S: fix __nop macro rept number for ARMv7M

Patrice CHOTARD patrice.chotard at st.com
Fri May 12 00:22:02 PDT 2017


Hi all

It's a gentle reminder to not forgot this patch.

Thanks

Patrice

On 04/25/2017 11:01 AM, patrice.chotard at st.com wrote:
> From: Patrice Chotard <patrice.chotard at st.com>
>
> In zImage, _magic_sig is located at offset 0x24.
> But for ARMv7M architecture which enable CPU_THUMBONLY
> and !EFI_STUB kernel flag, _magic_sig is located at offset 0x14
>
> 00000000  00 46 00 46 00 46 00 46  00 46 00 46 00 46 0f f2  |.F.F.F.F.F.F.F.ò|
> 00000010  15 0c 60 47 18 28 6f 01  00 00 00 00 28 5c 0e 00  |..`G.(o.....(\..|
> 00000020  01 02 03 04 0f 46 90 46  00 00 00 00 00 00 00 00  |.....F.F........|
>
> Reproduced with stm32_defconfig with XIP_KERNEL flag disabled.
>
> To restore correct _magic_sig offset at 0x24, we add 8 additional
> "mov r0, r0" instruction.
>
> Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
> ---
>  arch/arm/boot/compressed/head.S | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
> index 9150f97..5d9cda3 100644
> --- a/arch/arm/boot/compressed/head.S
> +++ b/arch/arm/boot/compressed/head.S
> @@ -127,7 +127,8 @@
>   AR_CLASS(	.arm	)
>  start:
>  		.type	start,#function
> -		.rept	7
> +   ARM(		.rept	7)
> + THUMB(		.rept	15)
>  		__nop
>  		.endr
>     ARM(		mov	r0, r0		)
>


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