imx: support i.MX8QM DMSSE20 a1 board

Add i.MX8QM DMSSE20 a1 board support

U-Boot 2023.04-00030-g7be2f547b2 (Apr 21 2023 - 11:11:43 +0200)

Model: Advantech iMX8QM DMSSE20
Board: DMS-SE20A1 8GB
Build: SCFW 549b1e18, SECO-FW c9de51c0, ATF 5782363
Boot:  USB
DRAM:  8 GiB
Core:  100 devices, 19 uclasses, devicetree: separate
MMC:   FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... OK
In:    serial@5a060000
Out:   serial@5a060000
Err:   serial@5a060000
Net:   eth0: ethernet@5b040000
Warning: ethernet@5b050000 (eth1) using random MAC address - 32:05:0c:f9:5e:10
, eth1: ethernet@5b050000
Hit any key to stop autoboot:  0

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
diff --git a/doc/board/advantech/imx8qm-dmsse20-a1.rst b/doc/board/advantech/imx8qm-dmsse20-a1.rst
new file mode 100644
index 0000000..b83e678
--- /dev/null
+++ b/doc/board/advantech/imx8qm-dmsse20-a1.rst
@@ -0,0 +1,58 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+NXP i.MX8QM DMSSE20-a1 board
+============================
+
+Quick Start
+-----------
+
+- Build the ARM Trusted firmware binary
+- Get scfw_tcm.bin and ahab-container.img
+- Get imx-mkimage
+- Build U-Boot
+- Flash the binary into the SD card
+- Boot
+
+Get and Build the ARM Trusted Firmware
+--------------------------------------
+
+.. code-block:: bash
+
+     $ git clone https://github.com/nxp-imx/imx-atf
+     $ cd imx-atf/
+     $ git checkout lf-5.10.72-2.2.0 -b lf-5.10.72-2.2.0
+     $ make PLAT=imx8qm bl31
+     $ cp build/imx8qm/release/bl31.bin $(builddir)
+
+Get scfw_tcm.bin and ahab-container.img
+---------------------------------------
+
+.. code-block:: bash
+
+     $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/imx-sc-firmware-1.11.0.bin
+     $ chmod +x imx-sc-firmware-1.11.0.bin
+     $ ./imx-sc-firmware-1.11.0.bin
+     $ wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/imx-seco-3.8.5.bin
+     $ chmod +x imx-seco-3.8.5.bin
+     $ ./imx-seco-3.8.5.bin
+
+Or use this to avoid running random scripts from the internet,
+but note that you must agree to the license the script displays:
+
+.. code-block:: bash
+
+     $ dd if=imx-sc-firmware-1.11.0.bin of=imx-sc-firmware-1.11.0.tar.bz2 bs=42757 skip=1
+     $ tar -xf imx-sc-firmware-1.11.0.tar.bz2
+     $ cp imx-sc-firmware-1.11.0/mx8qm-val-scfw-tcm.bin $(builddir)
+     $ dd if=imx-seco-3.8.5.bin of=imx-seco-3.8.5.tar.bz2 bs=43978 skip=1
+     $ tar -xf imx-seco-3.8.5.tar.bz2
+     $ cp imx-seco-3.8.5/firmware/seco/mx8qmb0-ahab-container.img $(builddir)
+
+Build U-Boot
+------------
+.. code-block:: bash
+
+     $ export ATF_LOAD_ADDR=0x80000000
+     $ export BL33_LOAD_ADDR=0x80020000
+     $ make imx8qm_dmsse20a1_defconfig
+     $ make