[U-Boot] [PATCH v2 3/4] ARM: use r9 for gd

[Jeroen Hofstee]

On 08/17/2013 11:40 AM, Jeroen Hofstee wrote:
> On 08/14/2013 08:25 PM, Jeroen Hofstee wrote:
>> To be more EABI compliant and as a preparation for building
>> with clang, use the platform-specific r9 register for gd
>> instead of r8.
>>
>> note: The FIQ is not updated since it is not used in u-boot,
>> and under discussion for the time being.
>>
>> The following checkpatch warning is ignored:
>> WARNING: Use of volatile is usually wrong: see
>> Documentation/volatile-considered-harmful.txt
>>
>> cc: Albert ARIBAUD <albert.u.boot at aribaud.net>
>> Signed-off-by: Jeroen Hofstee <jeroen at myspectrum.nl>
>> ---
>>   arch/arm/config.mk                 |  2 +-
>>   arch/arm/include/asm/global_data.h |  2 +-
>>   arch/arm/lib/crt0.S                | 16 ++++++++--------
>>   3 files changed, 10 insertions(+), 10 deletions(-)
>>
>
> This patch assumes only crt0.S sets the register used for
> gd in asm. I just noticed cpu/armv7/lowlevel_init.S does set gd
> manually, so all users of the common board.c are likely
> bricked with the patch as is. Looking into it....

Looking into this, it seems lowlevel_init.S could simply be removed
by placing the call to s_init at a better spot. As Tom pointed out,
this is already being discussed at [1]. As that is a topic of its own
I intend to simply change lowlevel_init.S to us r9 in this patchset.

Regards,
Jeroen

[1] 
http://u-boot.10912.n7.nabble.com/PATCH-1-3-arm-spl-Fix-SPL-booting-for-OMAP3-td156990.html