[Buildroot] [PATCH 1/2] boot/arm-trusted-firmware: Update FIP image generation with BL33_CFG option

[Thomas Petazzoni]

Hello Köry,

On Fri,  9 Jul 2021 11:49:24 +0200
Kory Maincent <kory.maincent at bootlin.com> wrote:

> Update the FIP image generation by adding the BL33_CFG parameter.
> This is needed for the ST version of ATF.
> 
> Signed-off-by: Kory Maincent <kory.maincent at bootlin.com>
> ---
>  boot/arm-trusted-firmware/Config.in               | 9 +++++++++
>  boot/arm-trusted-firmware/arm-trusted-firmware.mk | 4 ++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/boot/arm-trusted-firmware/Config.in b/boot/arm-trusted-firmware/Config.in
> index 7e46a10270..80f6161597 100644
> --- a/boot/arm-trusted-firmware/Config.in
> +++ b/boot/arm-trusted-firmware/Config.in
> @@ -133,6 +133,15 @@ config BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_BL33_IMAGE
>  	  Name of the U-Boot BL33 image to include in ATF, it must
>  	  have been installed to BINARIES_DIR by the U-Boot package.
>  
> +config BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_BL33_IMAGE_CFG
> +	string "U-Boot BL33 image devicetree name"
> +	default ""
> +	help
> +	  Name of the U-Boot BL33 image devicetree to include in ATF.
> +	  It must have been installed to BINARIES_DIR by the U-Boot
> +	  package.
> +	  Needed for the stm32mp1 platform.
> +
>  endif
>  
>  config BR2_TARGET_ARM_TRUSTED_FIRMWARE_EDK2_AS_BL33
> diff --git a/boot/arm-trusted-firmware/arm-trusted-firmware.mk b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> index 1f08f5dabb..9fc8b51a80 100644
> --- a/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> +++ b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
> @@ -92,6 +92,10 @@ endif
>  ifeq ($(BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_AS_BL33),y)
>  ARM_TRUSTED_FIRMWARE_UBOOT_BIN = $(call qstrip,$(BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_BL33_IMAGE))
>  ARM_TRUSTED_FIRMWARE_MAKE_OPTS += BL33=$(BINARIES_DIR)/$(ARM_TRUSTED_FIRMWARE_UBOOT_BIN)
> +ARM_TRUSTED_FIRMWARE_UBOOT_BIN_CFG = $(call qstrip,$(BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_BL33_IMAGE_CFG))
> +ifneq ($(ARM_TRUSTED_FIRMWARE_UBOOT_BIN_CFG),)
> +ARM_TRUSTED_FIRMWARE_MAKE_OPTS += BL33_CFG=$(BINARIES_DIR)/$(ARM_TRUSTED_FIRMWARE_UBOOT_BIN_CFG)
> +endif

What I don't like about this is that (for now) this BL33_CFG variable
is specific to the ST fork of TF-A. If we start adding support for all
the random variables that vendor-specific forks create, it's soon going
to be a nightmare.

Instead of this, could you try to add something like:

BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES="BL33_CFG=$(BINARIES_DIR)/your-dtb.dtb"

and see if that works ?

Best regards,

Thomas
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com