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

[Tim Harvey]

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.

Tim