Re: [PATCH v10 2/3] ARM: uncompress: Add OF_DT_MAGIC macro

[Ard Biesheuvel]

On Thu, 3 Dec 2020 at 13:19, Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>
> The DTB magic marker is stored as a 32-bit big-endian value, and thus
> depends on the CPU's endianness.  Add a macro to define this value in
> native endianness, to reduce #ifdef clutter and (future) duplication.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx>

> ---
> v10:
>   - New.
> ---
>  arch/arm/boot/compressed/head.S | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
> index aabdc544c03aafdc..d9cce7238a365081 100644
> --- a/arch/arm/boot/compressed/head.S
> +++ b/arch/arm/boot/compressed/head.S
> @@ -11,6 +11,12 @@
>
>  #include "efi-header.S"
>
> +#ifdef __ARMEB__
> +#define OF_DT_MAGIC 0xd00dfeed
> +#else
> +#define OF_DT_MAGIC 0xedfe0dd0
> +#endif
> +
>   AR_CLASS(     .arch   armv7-a )
>   M_CLASS(      .arch   armv7-m )
>
> @@ -335,11 +341,7 @@ restart:   adr     r0, LC1
>   */
>
>                 ldr     lr, [r6, #0]
> -#ifndef __ARMEB__
> -               ldr     r1, =0xedfe0dd0         @ sig is 0xd00dfeed big endian
> -#else
> -               ldr     r1, =0xd00dfeed
> -#endif
> +               ldr     r1, =OF_DT_MAGIC
>                 cmp     lr, r1
>                 bne     dtb_check_done          @ not found
>
> --
> 2.25.1
>