[U-Boot] [PATCH 3/4] arm: debug: import debug files from Linux 3.16

[Przemyslaw Marczak]

Hello Masahiro,

On 08/26/2014 05:26 AM, Masahiro Yamada wrote:
> Hi Przemyslaw,
>
>
> On Mon, 25 Aug 2014 11:03:13 +0200
> Przemyslaw Marczak <p.marczak at samsung.com> wrote:
>
>> Hello Masahiro,
>> I tried to test this on Trats2(Exynos4412) with required files from the linux and the code doesn't build.
>>
>> On 08/17/2014 08:16 AM, Masahiro Yamada wrote:
>>> U-Boot does not have arch/arm/kernel, include/uapi directories,
>>> This commit copies files as follows:
>>>
>>> +		.text
>>> +
>>> +/*
>>> + * Some debugging routines (useful if you've got MM problems and
>>> + * printk isn't working).  For DEBUGGING ONLY!!!  Do not leave
>>> + * references to these in a production kernel!
>>> + */
>>> +
>>> +#if !defined(CONFIG_DEBUG_SEMIHOSTING)
>>> +#include CONFIG_DEBUG_LL_INCLUDE
>>> +#endif
>>> +
>>> +#ifdef CONFIG_MMU
>>
>> This config: "CONFIG_MMU" is nowhere defined in the u-boot.
>
> Yes, CONFIG_MMU is never defined in U-Boot,
> therefore, the code inside #ifdef CONFIG_MMU  ... #endif  is never enabled.
>
>
>
>> U-boot uses (n)def CONFIG_SYS_DCACHE_OFF - for enable/disable the mmu in ARM.
>
> CONFIG_SYS_DCACHE_OFF has nothing to do with this debug function.
>
>
>> But when I do the change like this:
>> -#ifdef CONFIG_MMU
>> +#ifndef CONFIG_SYS_DCACHE_OFF
>>
>> Then I got the data abort, after use a printch(). But without this change the printch() function works fine (after the uart init).
>
> Please do not change this part.
> On U-Boot, virt addr is always the same as phys addr,
> so use the code for non CONFIG_MMU.

Ok, I see.

>
>
>
>>> +		.macro	addruart_current, rx, tmp1, tmp2
>>> +		addruart	\tmp1, \tmp2, \rx
>>> +		mrc		p15, 0, \rx, c1, c0
>>> +		tst		\rx, #1
>>> +		moveq		\rx, \tmp1
>>> +		movne		\rx, \tmp2
>>> +		.endm
>>> +
>>> +#else /* !CONFIG_MMU */
>>> +		.macro	addruart_current, rx, tmp1, tmp2
>>> +		addruart	\rx, \tmp1
>> Generates build error:
>> This asm macro: "addruart" gets 3 arguments but in this place got only two. After fix - works fine.
>> It's strange, no one use this in the kernel before?
>
>
> I guess you imported arch/arm/include/debug/exynos.S
>
>
> In Linux, unfortunately, the number of arguments of this macro is different
> between CONFIG_MMU and non CONFIG_MMU.
>
> (Fox ex, addruart in arch/arm/include/debug/efm32.S in Linux gives only two arguments.)
>
>
>
>
>
> Could you modify as follows and try it again, please?
>
>
>   --- a/arch/arm/lib/debug.S
>   +++ b/arch/arm/lib/debug.S
>   @@ -33,7 +33,7 @@
>
>    #else /* !CONFIG_MMU */
>                   .macro  addruart_current, rx, tmp1, tmp2
>   -               addruart        \rx, \tmp1
>   +               addruart        \rx, \tmp1, \tmp2

Yes, I fixed it by the same way before and it works fine with that change.

>                   .endm
>
>    #endif /* CONFIG_MMU */
>
>
>
>
> If it works, I will post v2.
>
>
>
> Best Regards
> Masahiro Yamada
>
>
>> And moreover I think that functions declarations are welcome for this code.
>>
>> Best regards,
>> -- Przemyslaw Marczak
>> Samsung R&D Institute Poland
>> Samsung Electronics
>> p.marczak at samsung.com

Best Regards,
-- 
Przemyslaw Marczak
Samsung R&D Institute Poland
Samsung Electronics
p.marczak at samsung.com