[U-Boot] [PATCH V2 1/3] arm: discard relocation entry for secure section

[Peng Fan <b51431@freescale.com>]

Hi Albert,

On Tue, Oct 20, 2015 at 09:05:32AM +0200, Albert ARIBAUD wrote:
>Hello Peng,
>
>On Tue, 20 Oct 2015 13:59:53 +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 the relocation entries for code in secure section.
>
>Actually, I'll need you to do a slight change -- that's my fault, and
>karma even ensured that my own self of two years ago would be the one
>to come and kick me. See:
>
>http://lists.denx.de/pipermail/u-boot/2013-December/168652.html

Ok. Then arch/arm/cpu/armv8/u-boot.lds should also have such fix,
since lots sections are discarded in u-boot.lds for armv8.

>
>Which basically is about never discarding any section in the ELF file,
>and only copying a subset of the ELF sections into the binary file.
>
>So rather than discarding the secure relocation records, let's move
>them to another section as you had proposed, and thus change the line
>
>> +	/DISCARD/ : { *(.rel._secure*) }
>
>Into a
>
>	.rel._secure { *(.rel._secure*) }
>
>Placed right after the already present
>
>	.dynamic : { *(.dynamic*) }

It can not be placed after .dynamic, since the following is at front.
87         .rel.dyn : {
88                 *(.rel*)
89         }
So relocation entry from secure text will first placed into .rel.dyn section.

If not DISCARD, then I prefer to put ".rel.secure : { *(.rel._secure*) }"
at line 55 which is wrapped by CONFIG_ARMV7_NONSEC in arch/arm/cpu/u-boot.lds.

See following patch: