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In-Reply-To: <20201203121916.2870975-3-geert+renesas@glider.be>
From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Thu, 3 Dec 2020 13:50:08 +0100
Message-ID: <CAMj1kXGy=ZLRg_+d-amY2FNj7hrZOM2umHcCiFYY5_eZsG95AQ@mail.gmail.com>
Subject: Re: [PATCH v10 2/3] ARM: uncompress: Add OF_DT_MAGIC macro
To:     Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Russell King <linux@armlinux.org.uk>,
        Nicolas Pitre <nico@fluxnic.net>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Dmitry Osipenko <digetx@gmail.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Eric Miao <eric.miao@nvidia.com>,
        =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Lukasz Stelmach <l.stelmach@samsung.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Chris Brandt <chris.brandt@renesas.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Thu, 3 Dec 2020 at 13:19, Geert Uytterhoeven <geert+renesas@glider.be> 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@glider.be>

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

> ---
> 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
>