[U-Boot] [RFC PATCH 6/8] omap3_beagle: add nand_spl support

[John Rigby]

On Fri, Jan 7, 2011 at 11:33 PM, Aneesh V <aneesh at ti.com> wrote:
> Hi John,
>
> On Tuesday 28 December 2010 06:17 AM, John Rigby wrote:
>>
>> Signed-off-by: John Rigby<john.rigby at linaro.org>
>> +
>> +void board_init_f(unsigned long bootflag)
>> +{
>> +       nand_boot();
>> +}
>> +
>
> I see that you have added a call to nand_boot() in start.S too.
> Which is the intended one?
> If we jump to nand_boot() here bss will not be cleared, right?
>
> Also, I see potential issues in start.S that will prevent bss setup for
> PRELOADERs. I will correct these in my patch.
>
> Best regards,
> Aneesh
>

The call to nand_boot in board_init_f makes sense for platforms where
the spl code does not need to be relocated because it has been loaded
into SRAM by a mask boot rom.  The later nand_boot called from start.S
is for the traditional nand_spl case where you are typically running
in a 4K nand controller buffer so the code needs to be relocated to
dram after dram init.

Of course my only testing has been on OMAP3 which fits the first case.
 I'm not sure if the second case even matters.  The arm7 platforms I
know about all have rom boot loaders and large enough SRAM to run the
spl u-boot in (OMAP[34]) or have boot headers that can be used to init
dram before loading a full u-boot into dram (i.mx5[13]).

Also, I was thinking that BSS would not be used in PRELOADERs but of
the large SRAM case it certainly would be useful to have BSS.

This is all new territory since previously all platforms using
nand_spl were of the small sram variety.

John