[U-Boot] powerpc/mpc85xx: Increase image size

[York Sun]

On 10/16/2013 02:23 PM, Scott Wood wrote:
> On Wed, 2013-10-16 at 13:44 -0700, York Sun wrote:
>> On 10/16/2013 01:41 PM, Scott Wood wrote:
>>> On Wed, 2013-10-16 at 13:38 -0700, York Sun wrote:
>>>> On 10/16/2013 01:33 PM, Scott Wood wrote:
>>>>> On Wed, 2013-10-16 at 13:32 -0700, York Sun wrote:
>>>>>> On 10/16/2013 01:29 PM, Scott Wood wrote:
>>>>>>> On Wed, 2013-10-16 at 13:22 -0700, York Sun wrote:
>>>>>>>> On 10/16/2013 12:37 PM, Scott Wood wrote:
>>>>>>>>> On Wed, 2013-10-16 at 10:41 -0700, York Sun wrote:
>>>>>>>>>> Are SPL and TPL boot methods immune from the size issue here?
>>>>>>>>>
>>>>>>>>> Sort of.  We still need to fit inside existing partition tables.
>>>>>>>>>
>>>>>>>>
>>>>>>>> PBL boot will be broken if the image size is bigger than 512KB, right?
>>>>>>>
>>>>>>> It has to be even smaller than that, to make room for early data.
>>>>>>>
>>>>>>
>>>>>> So if we go with 768KB, do we have to convert all PBL boot to SPL boot?
>>>>>
>>>>> Only the targets that need the extra space.
>>>>>
>>>>
>>>> We have T4, B4 and corenet_ds using PBL boot. They most likely will
>>>> exceed the 512KB soon, if not yet. It maybe easier to change all of them
>>>> togther, than one by one.
>>>
>>> There's no reason to change them all at once.  It doesn't make anything
>>> easier; it just means you have to do a bunch of testing all at once, and
>>> force a change in procedure for users on boards where it otherwise would
>>> not have been required.
>>
>> You are right here.
>>
>>>
>>> Plus, the 512K limit is for e500v2-based chips.  Newer chips have CPC
>>> for SRAM which is larger than 512K.
>>>
>>
>> Hmm? T4240 has 512KB CPC.
> 
> Each CPC is 512K, but there are three of them.  Is it possible to use
> more than one for SRAM, contiguously?

I think it is possible to use two CPC. The PBL boot method is hard-coded
to take 512KB u-boot.bin and generate u-boot.pbl. It surely can be
improved. My point is making a move for all concerned platforms may be
easier for maintenance.

York