[U-Boot] [PATCH 1/3] ARmv7: Add a soc_init hook to start.S

[Hans de Goede]

Hi,

On 22-01-15 17:20, Tom Rini wrote:
> On Wed, Jan 21, 2015 at 09:03:25PM +0100, Hans de Goede wrote:
>
>> On some SoCs / ARMv7 CPU cores we need to do some setup before enabling the
>> icache, etc. Add a soc_init hook with a weak default which just calls
>> cpu_init_cp15.
>>
>> This way different implementations can be provided to do some extra work
>> before or after cpu_init_cp15, or completely replacing cpu_init_cp15.
>>
>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>> ---
>>   arch/arm/cpu/armv7/start.S | 18 +++++++++++++++++-
>>   1 file changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
>> index fdc05b9..9882b20 100644
>> --- a/arch/arm/cpu/armv7/start.S
>> +++ b/arch/arm/cpu/armv7/start.S
>> @@ -64,7 +64,7 @@ reset:
>>
>>   	/* the mask ROM code should have PLL and others stable */
>>   #ifndef CONFIG_SKIP_LOWLEVEL_INIT
>> -	bl	cpu_init_cp15
>> +	bl	soc_init
>>   	bl	cpu_init_crit
>>   #endif
>
> I like the direction here.  And I want to make sure I get the sunxi
> direction right here too (as I agree with the need / desire for boot0 +
> U-Boot to be a valid combination).  I think we can take this a step
> farther.  cpu_init_crit (on armv7) is basically a call to s_init().
>
> For am33xx (and I bet but need to do and test omap3+) we can, with
> Simon's patch to let us move stack to DDR a tiny bit later, in the SPL
> case make s_init empty, which just leaves us with (with your patch)
> soc_init.  Is there some way we can put all of this together in a
> function?

You mean essentially call s_init here and have s_init call cpu_init_cp15
I guess we could do that, but it would require auditing all existing armv7
users of s_init. This may require me to rethink how / when I do timer &
gpio init etc. for u-boot.bin on sunxi, but that should not be a (big)
problem.

Regards,

Hans