[PATCH 8/8] doc: add documentation for am6254atl SiP

[Bryan Brattlof]

On October 22, 2025 thus sayeth Anshul Dalal:
> Adds documentation for the newly added am6254atl EVM board along with
> build instructions.
> 
> The content is largely similar to instructions for AM62x with updated
> TFA and OPTEE build args to account for the changes to A53 and OPTEE's
> load address.
> 
> Signed-off-by: Anshul Dalal <anshuld at ti.com>
> ---
>  doc/board/ti/am6254atl_sk.rst | 313 ++++++++++++++++++++++++++++++++++++++++++
>  doc/board/ti/k3.rst           |   1 +
>  2 files changed, 314 insertions(+)
> 
> diff --git a/doc/board/ti/am6254atl_sk.rst b/doc/board/ti/am6254atl_sk.rst
> new file mode 100644
> index 0000000000000000000000000000000000000000..480c0b07cfa85ebae495593b40c6a34692b15cda
> --- /dev/null
> +++ b/doc/board/ti/am6254atl_sk.rst
> @@ -0,0 +1,313 @@
> +.. SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
> +.. sectionauthor:: Anshul Dalal <anshuld at ti.com>
> +
> +AM6254ATL SIP Platforms
> +=======================
> +
> +Introduction:
> +-------------
> +
> +The AM6254atl SIP (System In Package) provides existing :doc:`am62x_sk` with
> +512MiB of DDR integrated in a single packages.
> +
> +More details can be found in the Technical Reference Manual:
> +https://www.ti.com/lit/pdf/spruiv7
> +
> +Platform information:
> +
> +* https://www.ti.com/tool/SK-AM62-SIP
> +
> +Boot Flow:
> +----------
> +Below is the pictorial representation of boot flow:
> +
> +.. image:: img/boot_diagram_am62.svg
> +  :alt: Boot flow diagram
> +
> +- Here TIFS acts as master and provides all the critical services. R5/A53
> +  requests TIFS to get these services done as shown in the above diagram.
> +
> +Sources:
> +--------
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_boot_sources
> +    :end-before: .. k3_rst_include_end_boot_sources
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_boot_firmwares
> +    :end-before: .. k3_rst_include_end_tifsstub
> +
> +Build procedure:
> +----------------
> +0. Setup the environment variables:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_common_env_vars_desc
> +    :end-before: .. k3_rst_include_end_common_env_vars_desc
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_board_env_vars_desc
> +    :end-before: .. k3_rst_include_end_board_env_vars_desc
> +
> +Set the variables corresponding to this platform:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_common_env_vars_defn
> +    :end-before: .. k3_rst_include_end_common_env_vars_defn
> +.. prompt:: bash $
> +
> +  export UBOOT_CFG_CORTEXR=am6254atl_evm_r5_defconfig
> +  export UBOOT_CFG_CORTEXA=am6254atl_evm_a53_defconfig
> +  export TFA_BOARD=lite
> +  export TFA_EXTRA_ARGS="PRELOADED_BL33_BASE=0x81880000 BL32_BASE=0x80080000"
> +  export OPTEE_PLATFORM=k3-am62x
> +  export OPTEE_EXTRA_ARGS="CFG_TZDRAM_START=0x80080000"
> +
> +1. Trusted Firmware-A:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_build_steps_tfa
> +    :end-before: .. k3_rst_include_end_build_steps_tfa
> +
> +
> +2. OP-TEE:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_build_steps_optee
> +    :end-before: .. k3_rst_include_end_build_steps_optee
> +
> +3. U-Boot:
> +
> +* 3.1 R5:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_build_steps_spl_r5
> +    :end-before: .. k3_rst_include_end_build_steps_spl_r5
> +
> +* 3.1.1 Alternative build of R5 for DFU boot:
> +
> +As the SPL size can get too big when building with support for booting both
> +from local storage *and* DFU an extra config fragment should be used to enable
> +DFU support (and disable storage support)
> +
> +.. prompt:: bash $
> +
> +  export UBOOT_CFG_CORTEXR="${UBOOT_CFG_CORTEXR} am62x_r5_usbdfu.config"
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_build_steps_spl_r5
> +    :end-before: .. k3_rst_include_end_build_steps_spl_r5
> +
> +* 3.2 A53:
> +
> +.. include::  ../ti/k3.rst
> +    :start-after: .. k3_rst_include_start_build_steps_uboot
> +    :end-before: .. k3_rst_include_end_build_steps_uboot
> +
> +Target Images
> +-------------
> +
> +In order to boot we need tiboot3.bin, tispl.bin and u-boot.img.  Each SoC
> +variant (GP, HS-FS, HS-SE) requires a different source for these files.
> +
> + - GP
> +
> +        * tiboot3-am62x-gp-evm.bin from step 3.1
> +        * tispl.bin_unsigned, u-boot.img_unsigned from step 3.2

I doubt we will sell GP silicon in the SiP layout. It's probably best we 
remove this to avoid any confusion.

~Bryan