[Buildroot] [PATCH v8 03/10] boot/uboot: add support for building the TI K3 DM into U-Boot

[Thomas Petazzoni]

Hello Andreas,

On Thu, 15 Jun 2023 19:23:52 -0500
Andreas Dannenberg via buildroot <buildroot at buildroot.org> wrote:

> Certain TI K3 devices such as AM62x and AM62Ax require a Device Manager
> (DM) firmnware to be made available to the U-Boot build, which will get
> packaged into the "tispl.bin" image tree blob during A53 SPL build.
> Without that DM firmware U-Boot will not be functional. To support this,
> add a config option called BR2_TARGET_UBOOT_NEEDS_TI_K3_DM to enable
> this feature, and another option BR2_TARGET_UBOOT_TI_K3_DM_SOC to allow
> setting the name of the SOC which needs to match the corresponding
> folder name in the ti-linux-firmware Git repository.
> 
> Signed-off-by: Andreas Dannenberg <dannenberg at ti.com>

I've also applied this patch to our next branch, with some changes. The
main one being that the U-Boot package is no longer responsible for
downloading the ti-dm firmware, it is now done by the separate
ti-k3-boot-firmware package.

> diff --git a/boot/uboot/Config.in b/boot/uboot/Config.in
> index 085397d03d..7e1dd44196 100644
> --- a/boot/uboot/Config.in
> +++ b/boot/uboot/Config.in
> @@ -240,6 +240,23 @@ config BR2_TARGET_UBOOT_NEEDS_OPTEE_TEE
>  	  U-Boot, and that the TEE variable pointing to OPTEE's
>  	  tee.elf, is passed during the Buildroot build.
>  
> +config BR2_TARGET_UBOOT_NEEDS_TI_K3_DM
> +	bool "U-Boot needs TI K3 Device Manager (DM)"
> +	help
> +	  Some TI K3 devices need the Device Manager (DM) firmware
> +	  to be available for the U-Boot build. Currently supports FW
> +	  from Git tag 08.06.00.006 by default.
> +
> +	  https://git.ti.com/cgit/processor-firmware/ti-linux-firmware/tree/ti-dm?h=ti-linux-firmware
> +
> +config BR2_TARGET_UBOOT_TI_K3_DM_SOC
> +	string "TI K3 Device Manager (DM) SOC Type"
> +	depends on BR2_TARGET_UBOOT_NEEDS_TI_K3_DM
> +	help
> +	  Name of the TI K3 Device Manager (DM) SOC. This needs to
> +	  match one of the SOC-specific folders in within the ti-dm
> +	  folder of the ti-linux-firmware Git repository.

Changed to:

+config BR2_TARGET_UBOOT_NEEDS_TI_K3_DM
+       bool "U-Boot needs TI K3 Device Manager (DM)"
+       # We use the SoC selection defined for the ti-k3-image-gen
+       # package
+       depends on BR2_TARGET_TI_K3_IMAGE_GEN
+       depends on BR2_TARGET_TI_K3_IMAGE_GEN_SOC_AM62AX || BR2_TARGET_TI_K3_IMAGE_GEN_SOC_AM62X
+       help
+         Some TI K3 devices need the Device Manager (DM) firmware to
+         be available for the U-Boot build.
+
+if BR2_TARGET_UBOOT_NEEDS_TI_K3_DM
+
+config BR2_TARGET_UBOOT_TI_K3_DM_SOCNAME
+       string
+       default "am62axx" if BR2_TARGET_TI_K3_IMAGE_GEN_SOC_AM62AX
+       default "am62xx"  if BR2_TARGET_TI_K3_IMAGE_GEN_SOC_AM62X
+
+endif

Basically my idea here is to avoid replicating the selection of SoC,
which we have already defined in the ti-k3-image-gen configuration. So
we piggy-back on the options of this package to determine the SoC we're
working with.

> diff --git a/boot/uboot/uboot.mk b/boot/uboot/uboot.mk
> index 4eae8e95c3..48af69bd26 100644
> --- a/boot/uboot/uboot.mk
> +++ b/boot/uboot/uboot.mk
> @@ -184,6 +184,22 @@ UBOOT_DEPENDENCIES += optee-os
>  UBOOT_MAKE_OPTS += TEE=$(BINARIES_DIR)/tee.elf
>  endif
>  
> +ifeq ($(BR2_TARGET_UBOOT_NEEDS_TI_K3_DM),y)
> +# Currently supports the FW from Git tag 08.06.00.006 by default
> +TI_K3_DM_VERSION = 340194800a581baf976360386dfc7b5acab8d948
> +TI_K3_DM_SITE = https://git.ti.com/processor-firmware/ti-linux-firmware/blobs/raw/$(TI_K3_DM_VERSION)/ti-dm/$(BR2_TARGET_UBOOT_TI_K3_DM_SOC)
> +TI_K3_DM_SOURCE = ipc_echo_testb_mcu1_0_release_strip.xer5f
> +# This is not really nice but disable the hash check for the DM FW file. Main
> +# reason is all those DM FW files for different SoCs have the same(!) name in
> +# the Git repository they reside in, so it would be more difficult to distinguish
> +# between them for hash checking purposes. To work around this let's just
> +# rely and trust the official Git repo at ti.com is known-good which is also
> +# accessed through a secure transport.
> +BR_NO_CHECK_HASH_FOR += $(TI_K3_DM_SOURCE)
> +UBOOT_EXTRA_DOWNLOADS = $(TI_K3_DM_SITE)/$(TI_K3_DM_SOURCE)
> +UBOOT_MAKE_OPTS += DM=$(UBOOT_DL_DIR)/$(TI_K3_DM_SOURCE)
> +endif

Simplified to:

+ifeq ($(BR2_TARGET_UBOOT_NEEDS_TI_K3_DM),y)
+UBOOT_TI_K3_DM_SOCNAME = $(call qstrip,$(BR2_TARGET_UBOOT_TI_K3_DM_SOCNAME))
+UBOOT_DEPENDENCIES += ti-k3-boot-firmware
+UBOOT_MAKE_OPTS += DM=$(BINARIES_DIR)/ti-dm/$(UBOOT_TI_K3_DM_SOCNAME)/ipc_echo_testb_mcu1_0_release_strip.xer5f
+endif

Best regards,

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