board: phytec: phycore-imx93: Add phyBOARD-Segin-i.MX93 support

Add initial support for the PHYTEC phyBOARD-Segin-i.MX93 board based on
the PHYTEC phyCORE-i.MX93 SoM.

Supported features:
- 1GB LPDDR4 RAM
- eMMC
- external SD
- FEC Ethernet
- debug UART
- watchdog

Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Tested-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Yannic Moog <y.moog@phytec.de>

doc/board/phytec/imx93-phyboard-segin.rst

@@ -0,0 +1,61 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+phyBOARD-Segin-i.MX93
+=====================
+
+U-Boot for the phyBOARD-Segin-i.MX93.
+
+Quick Start
+-----------
+
+- Get and Build the ARM Trusted firmware
+- Get the DDR firmware
+- Get ahab-container.img
+- Build U-Boot
+
+Get and Build the ARM Trusted firmware
+--------------------------------------
+
+Note: srctree is U-Boot source directory
+Get ATF from: https://github.com/nxp-imx/imx-atf/
+branch: lf_v2.8
+
+.. code-block:: bash
+
+   $ unset LDFLAGS
+   $ make PLAT=imx93 bl31
+   $ cp build/imx93/release/bl31.bin $(srctree)
+
+Get the DDR firmware
+--------------------
+
+.. code-block:: bash
+
+   $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.21.bin
+   $ chmod +x firmware-imx-8.21.bin
+   $ ./firmware-imx-8.21.bin
+   $ cp firmware-imx-8.21/firmware/ddr/synopsys/lpddr4*.bin $(srctree)
+
+Get ahab-container.img
+---------------------------------------
+
+.. code-block:: bash
+
+   $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-sentinel-0.10.bin
+   $ chmod +x firmware-sentinel-0.10.bin
+   $ ./firmware-sentinel-0.10.bin
+   $ cp firmware-sentinel-0.10/mx93a0-ahab-container.img $(srctree)
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+   $ make imx93-phyboard-segin_defconfig
+   $ make
+
+Burn the flash.bin to MicroSD card offset 32KB:
+
+.. code-block:: bash
+
+   $ dd if=flash.bin of=/dev/sd[x] bs=1024 seek=32 conv=notrunc

doc/board/phytec/index.rst

@@ -7,6 +7,7 @@ PHYTEC
    :maxdepth: 2
 
    imx8mm-phygate-tauri-l
+   imx93-phyboard-segin
    phycore-am62x
    phycore-imx8mm
    phycore-imx8mp