[U-Boot] [Patch v2 1/2] common/board_f: Preserve global data for mpc85xx and mpc86xx

[York Sun]

On 04/30/2014 05:11 PM, Scott Wood wrote:
> On Wed, 2014-04-30 at 17:05 -0700, York Sun wrote:
>> On 04/30/2014 05:02 PM, Scott Wood wrote:
>>> On Wed, 2014-04-30 at 17:01 -0700, York Sun wrote:
>>>>>>> BTW, I see x86 also skips "gd = new_gd" in board_init_r(), so I wonder
>>>>>>> what is going on with gd on x86, and whether it makes sense to lump it
>>>>>>> in with CONFIG_SYS_EARLY_GD.
>>>>>>>
>>>>>>
>>>>>> Maybe x86 maintainers can chime in? If we define such macro, it should probably
>>>>>> sit right above board_init_f() so it can be seen easily. There is no other place
>>>>>> it is needed, yet.
>>>>>
>>>>> I was thinking it would be set the same way other CONFIG symbols are
>>>>> set.
>>>>>
>>>>
>>>> That will be in include/common.h for cross-platform macros.
>>>
>>> No, it's in the particular board files (or better, arch/subarch files
>>> included by board files) that need this.  The point is to not have a big
>>> ifdef list, rather than to just move the big ifdef list.
>>>
>>
>> I got your idea. You are suggesting to define this macro in each arch which it
>> needs to preserve gd. So we won't have a list. It is neat but may be easy to miss.
> 
> It's how other such things are handled.  We'd have a giant mess if we
> had lists of targets strewn throughout the codebase.
> 

This will be a negative logic,

#ifndef CONFIG_SYS_EARLY_GD
	gd_t data;

	gd =  &data;
	zero_global_data();
#endif

York