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

[Peng Fan]

On Fri, Oct 30, 2015 at 04:23:49PM +0800, Peng Fan wrote:
>Hi Albert,
>
>Are you fine with this patch?
>
>I'd like the patch go through i.MX tree, since the other two patches
>needs this patch to work.

Ping..

Thanks,
Peng.

>
>Thanks,
>Peng.
>
>On Fri, Oct 23, 2015 at 10:13:03AM +0800, Peng Fan 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 at freescale.com>
>>Cc: Tom Warren <twarren at nvidia.com>
>>Cc: York Sun <yorksun at freescale.com>
>>Cc: Hans De Goede <hdegoede at redhat.com>
>>Cc: Ian Campbell <ijc at hellion.org.uk>
>>Cc: Albert Aribaud <albert.u.boot at aribaud.net>
>>Cc: Tom Rini <trini at konsulko.com>
>>Cc: Jan Kiszka <jan.kiszka at siemens.com>
>>Cc: Stefano Babic <sbabic at 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
>>
>>
>
>-- 

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