Re: [PATCH 07/10] powerpc: Update linker scripts to ensure appended device tree is aligned

["Christophe Leroy (CS GROUP)" <chleroy@kernel.org>]

Le 15/01/2026 à 23:19, Tom Rini a écrit :
> With commit 0535e46d55d7 ("scripts/dtc: Update to upstream version
> v1.7.2-35-g52f07dcca47c") it is now a fatal error to U-Boot if our
> device tree is not 8-byte aligned. In commit f613a6e15ef7 ("ARM: OMAP2+:
> Pad SPL binary to 8-byte alignment before DTB") Beleswar Padhi explains
> that we must have ALIGN(x) statements inside of a section to ensure that
> padding is included and not simply that the linker address counter is
> incremented. To that end, this patch:
> - Aligns the final section before _end by 8-bytes by adding '. =
>    ALIGN(8);' or changing an existing ALIGN(4) statement.
> - Ensure that we do have alignment by adding an ASSERT so that when not
>    aligned we fail to link (and explain why).
> 
> Signed-off-by: Tom Rini <trini@konsulko.com>

Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

> ---
> Cc: "Marek Behún" <kabel@kernel.org>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Marek Vasut <marek.vasut+renesas@mailbox.org>
> Cc: Mario Six <mario.six@gdsys.cc>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> ---
>   arch/powerpc/cpu/mpc83xx/u-boot.lds | 3 +++
>   arch/powerpc/cpu/mpc85xx/u-boot.lds | 4 +++-
>   board/cssi/cmpc885/u-boot.lds       | 3 +++
>   board/cssi/mcr3000/u-boot.lds       | 3 +++
>   4 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/cpu/mpc83xx/u-boot.lds b/arch/powerpc/cpu/mpc83xx/u-boot.lds
> index 1a1e537b2a76..5becc4d236ef 100644
> --- a/arch/powerpc/cpu/mpc83xx/u-boot.lds
> +++ b/arch/powerpc/cpu/mpc83xx/u-boot.lds
> @@ -56,6 +56,7 @@ SECTIONS
>      * _end - This is end of u-boot.bin image.
>      * dtb will be appended here to make u-boot-dtb.bin
>      */
> +  . = ALIGN(8);
>     _end = .;
>   
>     . = ALIGN(4096);
> @@ -77,3 +78,5 @@ SECTIONS
>     PROVIDE (end = .);
>   }
>   ENTRY(_start)
> +
> +ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");
> diff --git a/arch/powerpc/cpu/mpc85xx/u-boot.lds b/arch/powerpc/cpu/mpc85xx/u-boot.lds
> index 3af0dfdf336b..3c9959bef097 100644
> --- a/arch/powerpc/cpu/mpc85xx/u-boot.lds
> +++ b/arch/powerpc/cpu/mpc85xx/u-boot.lds
> @@ -78,7 +78,7 @@ SECTIONS
>     __init_begin = .;
>     .text.init : { *(.text.init) }
>     .data.init : { *(.data.init) }
> -  . = ALIGN(4);
> +  . = ALIGN(8);
>     __init_end = .;
>     _end = .;
>   
> @@ -119,3 +119,5 @@ SECTIONS
>     __bss_end = . ;
>     PROVIDE (end = .);
>   }
> +
> +ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");
> diff --git a/board/cssi/cmpc885/u-boot.lds b/board/cssi/cmpc885/u-boot.lds
> index 167606357e00..da9cff64d465 100644
> --- a/board/cssi/cmpc885/u-boot.lds
> +++ b/board/cssi/cmpc885/u-boot.lds
> @@ -72,6 +72,7 @@ SECTIONS
>   	 * _end - This is end of u-boot.bin image.
>   	 * dtb will be appended here to make u-boot-dtb.bin
>   	 */
> +	. = ALIGN(8);
>   	_end = .;
>   
>   	. = ALIGN(4096);
> @@ -93,3 +94,5 @@ SECTIONS
>   	PROVIDE (end = .);
>   }
>   ENTRY(_start)
> +
> +ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");
> diff --git a/board/cssi/mcr3000/u-boot.lds b/board/cssi/mcr3000/u-boot.lds
> index 66afdebc0f77..1fd98726b2a8 100644
> --- a/board/cssi/mcr3000/u-boot.lds
> +++ b/board/cssi/mcr3000/u-boot.lds
> @@ -72,6 +72,7 @@ SECTIONS
>   	 * _end - This is end of u-boot.bin image.
>   	 * dtb will be appended here to make u-boot-dtb.bin
>   	 */
> +	. = ALIGN(8);
>   	_end = .;
>   
>   	. = ALIGN(4096);
> @@ -93,3 +94,5 @@ SECTIONS
>   	PROVIDE (end = .);
>   }
>   ENTRY(_start)
> +
> +ASSERT(_end % 8 == 0, "_end must be 8-byte aligned for device tree");