[U-Boot] [RFC PATCH] ARM: atmel: at91sam9m10g45ek: enable SPL

[Bo Shen]

Hi Heiko,

On 01/05/2015 03:59 PM, Heiko Schocher wrote:
>> +#ifdef CONFIG_SKIP_LOWLEVEL_INIT
>>   void spl_board_init(void)
>> +#else
>> +void s_init(void)
>> +#endif
>>   {
>>       struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
>
> ... and adding this "ifdefs" could be prevented ...
>
> What do you think?
>
> Ah! you wrote:
>
>  > As the boot from SD/MMC card with FAT file system, the BSS
>  > segment is too big to fit into SRAM, so, use the lds to put
>  > it into SDRAM. So, we need to initialize the SDRAM as soon
>  > as possible. Borrow the low level init code from
>  > <arm/arm/cpu/armv7/lowlevel_init.S> for this purpose.
>
> Hmm... maybe we can include this in the existing code? So we

The existed code is located in <arch/arm/cpu/armv7> directory, I think 
it is difficult to include it.

I think we can put it into <arch/arm/cpu/arm926ejs> directory, I am not 
sure it will help others. As other SoC has low level init code. Or, as 
the patch, put it into <arch/arm/cpu/arm926ejs/at91> directory for at91 
series only.

> have BSS for all at91 boards in RAM?

It depends, we still can put the BSS into SRAM use the common 
u-boot-spl.lds.
Only put BSS into SDRAM/DDR, when use u-boot-spl-arm9.lds.


> Or, if not possible, we should convert the existing boards into
> your framework ... if you can prepare such a patch I can test it
> on  the corvus, taurus and axm boards ...

If the upper method for low level initialize code is chosen, I will 
prepare such patch for the boards you mentioned.

> bye,
> Heiko

Best Regards,
Bo Shen