[U-Boot] [PATCH 11/24] sunxi: introduce extra config option for boot0 header

[Andre Przywara <andre.przywara@arm.com>]

Hi Maxime,

thanks for having a look!

On 21/11/16 07:27, Maxime Ripard wrote:
> Hi Andre,
> 
> On Sun, Nov 20, 2016 at 02:57:05PM +0000, Andre Przywara wrote:
>> The ENABLE_ARM_SOC_BOOT0_HOOK option is a generic option shared with
>> other boards. To allow alternative code to be inserted, we create
>> another, now function specific config symbol on top of it to simplify
>> later additions. No functional change at this time.
>>
>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>> ---
>>  board/sunxi/Kconfig           | 9 +++++++++
>>  configs/pine64_plus_defconfig | 2 +-
>>  2 files changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
>> index e1d4ab1..0cd57a2 100644
>> --- a/board/sunxi/Kconfig
>> +++ b/board/sunxi/Kconfig
>> @@ -133,6 +133,15 @@ config MACH_SUN8I
>>  	bool
>>  	default y if MACH_SUN8I_A23 || MACH_SUN8I_A33 || MACH_SUN8I_H3 || MACH_SUN8I_A83T
>>  
>> +config RESERVE_ALLWINNER_BOOT0_HEADER
>> +	bool "reserve space for Allwinner boot0 header"
>> +	select ENABLE_ARM_SOC_BOOT0_HOOK
>> +	---help---
>> +	Prepend a 1536 byte (empty) header to the U-Boot image file, to be
>> +	filled with magic values post build. The Allwinner provided boot0
>> +	blob relies on this information to load and execute U-Boot.
>> +	Only needed on 64-bit Allwinner boards so far when using boot0.
>> +
> 
> Is there a reason you can think of to disable it?

We need it only for booting from boot0, so this series actually makes
this whole thing obsolete. Since - apart from enlarging the U-Boot
(proper) image by 1.5KB - it doesn't hurt, though, my idea was to keep
it in as an option for some time until we are confident that boot0 is no
longer needed.

> If not, you should consider making this enabled by default, so that we
> don't enable it in all the defconfig for no particular reason.

I can change the logic, make the Kconfig entry "default y if ARM64", and
any defconfig could then choose to say "# RESERVE_... is not set".

Does that make more sense to you?

What was your major concern about this? Having pointless options in
various defconfigs?

Cheers,
Andre.