[U-Boot] [PATCH] arm: rmobile: Support build with gcc-4.6 or later

[Nobuhiro Iwamatsu]

Hi,

Thnak you for your comment.

2012/7/6 Tetsuyuki Kobayashi <koba at kmckk.co.jp>:
> Hello, Iwamatsu-san
>
> (2012/07/06 9:06), Nobuhiro Iwamatsu wrote:
>> Latest rmobile code was tested by using old gcc (gcc-4.4).
>> When we use gcc-4.6 (or later), the build is made, but does not work.
>> This solves a problem not to work by add -march=armv5 to compiple option
>> when we built in gcc-4.6 (or later).
>> I tested by linaro's compiler version 2012.04-20120426.
>
> Yes. I know recent gcc causes problem because of unaligned access.
> There are 2 different proposals, but neither accepted.
>
> [PATCH] arm: enable unaligned access on ARMv7
> http://lists.denx.de/pipermail/u-boot/2012-June/125754.html
>
> [PATCH] arm: armv7: add compile option -mno-unaligned-access if available
> http://lists.denx.de/pipermail/u-boot/2012-July/127260.html
>
> This patch is the third one.
>
>> --- a/arch/arm/cpu/armv7/rmobile/lowlevel_init.S
>> +++ b/arch/arm/cpu/armv7/rmobile/lowlevel_init.S
>> @@ -49,8 +49,6 @@ wait_interrupt:
>>       str     r2, [r1]
>>
>>   wait_loop:
>> -     wfi
>> -
>>       ldr             r2, [r1, #0xC]
>>       str             r2, [r1, #0x10]
>
> I know "wfi" instruction causes compile error in -march=armv5.
> Without this, it works but not so good because 2nd CPU wastes cycles.
>
> I wonder, is there any cheat such as ".word 0x...." (putting instruction code directly)
> or something.

I see.  I'll fix.

Thanks,
  Nobuhiro

-- 
Nobuhiro Iwamatsu