[PATCH 2/2] doc: board: toradex: add the Colibri VF50/VF61 page

[Mehmet Fide <mehmet.fide@gmail.com>]

From: Mehmet Fide <mehmet.fide@screeningeagle.com>

The other Toradex modules are documented here, the Vybrid ones were
not. Describe the build, the two ways of getting the image into NAND,
and the flashloader command of the WinCE-era bootloader that modules
from that era still carry.

Signed-off-by: Mehmet Fide <mehmet.fide@screeningeagle.com>
---
 doc/board/toradex/colibri_vf.rst | 70 ++++++++++++++++++++++++++++++++
 doc/board/toradex/index.rst      |  1 +
 2 files changed, 71 insertions(+)
 create mode 100644 doc/board/toradex/colibri_vf.rst

diff --git a/doc/board/toradex/colibri_vf.rst b/doc/board/toradex/colibri_vf.rst
new file mode 100644
index 00000000000..d2809bda2e8
--- /dev/null
+++ b/doc/board/toradex/colibri_vf.rst
@@ -0,0 +1,70 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+.. sectionauthor:: Mehmet Fide <mehmet.fide@screeningeagle.com>
+
+Colibri VF50/VF61 Modules
+=========================
+
+- SoM: https://www.toradex.com/computer-on-modules/colibri-arm-family/nxp-vybrid-vf5xx-vf6xx
+- Carrier boards: https://www.toradex.com/products/carrier-board/colibri-evaluation-board
+  and https://www.toradex.com/products/carrier-board/iris-carrier-board
+
+Quick Start
+-----------
+
+- Build U-Boot
+- Flash to NAND from a running U-Boot
+- Flash to NAND over recovery mode
+- Modules still carrying the WinCE bootloader
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+    $ export CROSS_COMPILE=arm-linux-gnueabi-
+    $ make colibri_vf_defconfig
+    $ make
+
+This produces ``u-boot.imx``, the image with the IVT for the Vybrid
+BootROM, ready to be written to the ``u-boot`` NAND partition.
+
+Flash to NAND from a running U-Boot
+-----------------------------------
+
+Load the image over TFTP or from a FAT formatted SD card and use the
+``update_uboot`` script from the default environment:
+
+.. code-block:: none
+
+    Colibri VFxx # fatload mmc 0:1 ${loadaddr} u-boot.imx
+    Colibri VFxx # run update_uboot
+    Colibri VFxx # reset
+
+Flash to NAND over recovery mode
+--------------------------------
+
+With nothing bootable in NAND, the Vybrid BootROM falls back to the
+serial downloader on the USB client port. The `imx_usb_loader
+<https://github.com/boundarydevices/imx_usb_loader>`_ tool can push
+``u-boot.imx`` straight into OCRAM and run it:
+
+.. code-block:: bash
+
+    $ imx_usb u-boot.imx
+
+From the running U-Boot, flash NAND as in the previous section.
+
+Modules still carrying the WinCE bootloader
+-------------------------------------------
+
+Modules that were shipped with the WinCE-era Toradex bootloader (eBoot)
+offer a ``flashloader`` command that writes a U-Boot image to NAND:
+
+.. code-block:: none
+
+    > flashloader u-boot.imx
+    > reboot
+
+The image must be linked at ``CONFIG_TEXT_BASE=0x3f408000``; the BootROM
+does not start an image linked at the bottom of the gfxRAM area, whether
+loaded through eBoot or from NAND.
diff --git a/doc/board/toradex/index.rst b/doc/board/toradex/index.rst
index 2a45bde6991..5bf2d052462 100644
--- a/doc/board/toradex/index.rst
+++ b/doc/board/toradex/index.rst
@@ -10,6 +10,7 @@ Toradex
    aquila-am69
    colibri_imx7
    colibri-imx8x
+   colibri_vf
    smarc-imx8mp
    smarc-imx95
    verdin-am62
-- 
2.54.0