[PATCH] configs: add support for stm32mp157c-dk2 board

[Patrick DELAUNAY <patrick.delaunay@st.com>]

Hi

> From: Arnaud Ferraris <arnaud.ferraris@collabora.com>
> Sent: mercredi 22 avril 2020 15:19
> 
> This config is based on stm32mp15_basic_defconfig and adds the necessary
> options to be able to boot a STM32MP157C-DK2 dev board.
> 
> Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
> ---
>  configs/stm32mp157c-dk2_defconfig | 131
> ++++++++++++++++++++++++++++++
>  1 file changed, 131 insertions(+)
>  create mode 100644 configs/stm32mp157c-dk2_defconfig
>

For information, stm32mp157c-dk2 board is already supported by stm32mp15_basic_defconfig
without the need of a specific defconfig (I am using it every day).

You just need to specify the used devictree with the generic Makefile parameter
DEVICE_TREE=stm32mp157c-dk2

For support details: ./doc/board/st/stm32mp1.rst
Or https://wiki.st.com/stm32mpu/wiki/STM32MP15_U-Boot

example

      # make stm32mp15_basic_defconfig
      # make DEVICE_TREE=stm32mp157c-dk2 all

Or

      # export KBUILD_OUTPUT=../build/stm32mp15_basic
      # export DEVICE_TREE= stm32mp157c-dk2
      # make stm32mp15_basic_defconfig
      # make all

CONFIG_DEFAULT_DEVICE_TREE only provide the default device tree used
when DEVICE_TREE is absent.

What it is the need to this new defconfig ?
U-Boot size optimization for DK2 only ?

PS: If something is missing in stm32mp15_basic_defconfig/stm32mp15_trusted_defconfig
       it should be added in this generic target common for all ST supported boards.

Regards

Patrick