[U-Boot] [PATCH 12/12] imx: ventana: switch to SPL

[York Sun]

On 05/07/2014 01:27 PM, Tim Harvey wrote:
> On Wed, May 7, 2014 at 9:14 AM, York Sun <yorksun at freescale.com> wrote:
>> On 05/06/2014 04:35 PM, Tim Harvey wrote:
>>> On Tue, May 6, 2014 at 12:11 PM, Jeroen Hofstee <dasuboot at myspectrum.nl> wrote:
>>>> Hello Tim,
>>>>
>> <snip>
>>>>
>>>> Since Crt0.S already created gd on the stack before calling
>>>> board_init_f, can't the assignment of gd not simply be removed?
>>>> Is there anything special about gdata?
>>>>
>>>> Regards,
>>>> Jeroen
>>>>
>>>>
>>>
>>> Jeroen,
>>>
>>> That does make sense, but what I find is that York's ocmmit
>>> dec1861be90c948ea9fb771927d3d26a994d2e20 requires that gd be blanked
>>> and its not. This causes bus_i2c_init to skip its initialization
>>> because p->base is not zero.
>>>
>>> York, does this make sense? Your patch creates a dependence on
>>> gd->srdata being blank which isn't the case with the SRAM when booting
>>> from the IMX6 boot rom.
>>>
>>
>> GD should be cleared (zeroed). Then we don't have this problem. Whoever sets up
>> gd (board_int_f, cpu_init_f, or others) should make sure gd is cleared. Why
>> isn't it the case for IMX6 boot rom?
>>
>> York
>>
> 
> York,
> 
> crt0.S is mapping gd to where the SPL stack pointer is defined, which
> is where Freescale says its stack pointer is for its firmware BOOT
> ROM, so its initial data will be dependent on what the BOOT ROM did.
> 
> I think the right solution is to have crt0.S zero it out.
>

Either crt0.S, or somewhere before gd is used for the first time. Can it be done
in board_init_f()?

York