[U-Boot] [PATCH V4 1/3] arm: discard relocation entries for secure text

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hello Peng,

On Fri, 23 Oct 2015 10:13:03 +0800, Peng Fan <Peng.Fan@freescale.com>
wrote:
> The code such as PSCI in section named secure is bundled with
> u-boot image, and when bootm, the code will be copied to their
> runtime address same to compliation/linking address -
> CONFIG_ARMV7_SECURE_BASE.
> 
> When compile the PSCI code and link it into the u-boot image,
> there will be relocation entries in .rel.dyn section for PSCI.
> Actually, we do not needs these relocation entries.
> 
> If still keep the relocation entries in .rel.dyn section,
> r0 at line 103 and 106 in arch/arm/lib/relocate.S may be an invalid
> address which may not support read/write for one SoC.
> 102         /* relative fix: increase location by offset */
> 103         add     r0, r0, r4
> 104         ldr     r1, [r0]
> 105         add     r1, r1, r4
> 106         str     r1, [r0]
> 
> So discard them to avoid touching the relocation entry in
> arch/arm/lib/relocate.S.
> 
> Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
> Cc: Tom Warren <twarren@nvidia.com>
> Cc: York Sun <yorksun@freescale.com>
> Cc: Hans De Goede <hdegoede@redhat.com>
> Cc: Ian Campbell <ijc@hellion.org.uk>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Jan Kiszka <jan.kiszka@siemens.com>
> Cc: Stefano Babic <sbabic@denx.de>
> ---
> 
> Changes v4:
>  none
> 
> V2 thread: http://lists.denx.de/pipermail/u-boot/2015-October/230755.html
> Changes v3:
>  Move the relocation entries to the very begining and discard them.
> 
> V1 thread: http://lists.denx.de/pipermail/u-boot/2015-October/229426.html
> Changes V2:
>  Refine commit msg.
>  Discard the relocation entry section for secure text.
> 
>  arch/arm/cpu/u-boot.lds | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
> index 03cd9f6..d48a905 100644
> --- a/arch/arm/cpu/u-boot.lds
> +++ b/arch/arm/cpu/u-boot.lds
> @@ -14,6 +14,23 @@ OUTPUT_ARCH(arm)
>  ENTRY(_start)
>  SECTIONS
>  {
> +	/*
> +	 * Discard the relocation entries for secure text.
> +	 * The secure code is bundled with u-boot image, so there will
> +	 * be relocations entries for the secure code, since we use
> +	 * "-mword-relocations" to compile and "-pie" to link into the
> +	 * final image. We do not need the relocation entries for secure
> +	 * code, because secure code will not be relocated, it only needs
> +	 * to be copied from loading address to CONFIG_ARMV7_SECURE_BASE,
> +	 * which is the linking and running address for secure code.
> +	 * If keep the relocation entries in .rel.dyn section,
> +	 * "relocation offset + linking address" may locates into an
> +	 * address that is reserved by SoC, then will trigger data abort.
> +	 *
> +	 * The reason that move .rel._secure at the beginning, is to
> +	 * avoid hole in the final image.
> +	 */
> +	/DISCARD/ : { *(.rel._secure*) }
>  	. = 0x00000000;
>  
>  	. = ALIGN(4);
> -- 
> 1.8.4
> 
> 

Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net>

Amicalement,
-- 
Albert.