docs(marvell): document UART image downloading

For A3K there are two different tools for booting Armada37x0 platform
over UART, one from Marvell and second from CZ.NIC. For A8K there is
just one my own mvebu64boot tool.

Add documentation how to build these tools and how to download TF-A
image over UART to boot TF-A without flashing it to non-volatile
storage.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: Ifa03584010a9c40496a34e6d5b9f3b78cb2cc89b

docs/plat/marvell/armada/uart-booting.rst

@@ -0,0 +1,103 @@
+TF-A UART Booting Instructions for Marvell Platforms
+====================================================
+
+This section describes how to temporary boot the Trusted Firmware-A (TF-A) project over UART
+without flashing it to non-volatile storage for Marvell's platforms.
+
+See :ref:`TF-A Build Instructions for Marvell Platforms` how to build ``mrvl_uart`` and
+``mrvl_flash`` targets used in this section.
+
+Armada37x0 UART image downloading
+---------------------------------
+
+There are two options how to download UART image into any Armada37x0 board.
+
+Marvell Wtpdownloader
+~~~~~~~~~~~~~~~~~~~~~
+
+Marvell Wtpdownloader works only with UART images stored in separate files and supports only upload
+speed with 115200 bauds. Target ``mrvl_uart`` produces GZIPed TAR archive ``uart-images.tgz.bin``
+with either three files ``TIM_ATF.bin``, ``wtmi_h.bin`` and ``boot-image_h.bin`` for non-secure
+boot or with four files ``TIM_ATF_TRUSTED.bin``, ``TIMN_ATF_TRUSTED.bin``, ``wtmi_h.bin`` and
+``boot-image_h.bin`` when secure boot is enabled.
+
+Compilation:
+
+.. code:: shell
+
+    > git clone https://github.com/MarvellEmbeddedProcessors/A3700-utils-marvell.git
+    > make -C A3700-utils-marvell/wtptp/src/Wtpdownloader_Linux -f makefile.mk
+
+It produces executable binary ``A3700-utils-marvell/wtptp/src/Wtpdownloader_Linux/WtpDownload_linux``
+
+To download images from ``uart-images.tgz.bin`` archive unpack it and for non-secure boot variant run:
+
+.. code:: shell
+
+    > stty -F /dev/ttyUSB<port#> clocal
+    > WtpDownload_linux -P UART -C <port#> -E -B TIM_ATF.bin -I wtmi_h.bin -I boot-image_h.bin
+
+After that immediately start terminal on ``/dev/ttyUSB<port#>`` to see boot output.
+
+CZ.NIC mox-imager
+~~~~~~~~~~~~~~~~~
+
+CZ.NIC mox-imager supports all Armada37x0 boards (not only Turris MOX as name suggests). It works
+with either with separate files from ``uart-images.tgz.bin`` archive (like Marvell Wtpdownloader)
+produced by ``mrvl_uart`` target or also with ``flash-image.bin`` file produced by ``mrvl_flash``
+target, which is the exactly same file as used for flashing. So when using CZ.NIC mox-imager there
+is no need to build separate files for UART flashing like in case with Marvell Wtpdownloader.
+
+CZ.NIC mox-imager moreover supports higher upload speeds up to the 6000000 bauds (which seems to
+be limit of Armada37x0 SoC) which is much higher and faster than Marvell Wtpdownloader.
+
+Compilation:
+
+.. code:: shell
+
+    > git clone https://gitlab.nic.cz/turris/mox-imager.git
+    > make -C mox-imager
+
+It produces executable binary ``mox-imager/mox-imager``
+
+To download single file image built by ``mrvl_flash`` target at the highest speed, run:
+
+.. code:: shell
+
+    > mox-imager -D /dev/ttyUSB<port#> -E -b 6000000 -t flash-image.bin
+
+To download images from ``uart-images.tgz.bin`` archive built by ``mrvl_uart`` target for
+non-secure boot variant (like Wtpdownloader) but at the highest speed, first unpack
+``uart-images.tgz.bin`` archive and then run:
+
+.. code:: shell
+
+    > mox-imager -D /dev/ttyUSB<port#> -E -b 6000000 -t TIM_ATF.bin wtmi_h.bin boot-image_h.bin
+
+CZ.NIC mox-imager after successful download will start its own mini terminal (option ``-t``) to
+not loose any boot output. It also prints boot output which is sent either by image files or by
+bootrom during transferring of image files. This mini terminal can be quit by CTRL-\\ + C keypress.
+
+
+A7K/8K/CN913x UART image downloading
+------------------------------------
+
+A7K/8K/CN913x uses same image ``flash-image.bin`` for both flashing and booting over UART.
+For downloading image over UART it is possible to use mvebu64boot tool.
+
+Compilation:
+
+.. code:: shell
+
+    > git clone https://github.com/pali/mvebu64boot.git
+    > make -C mvebu64boot
+
+It produces executable binary ``mvebu64boot/mvebu64boot``
+
+To download ``flash-image.bin`` image run:
+
+.. code:: shell
+
+    > mvebu64boot -t -b flash-image.bin /dev/ttyUSB0
+
+After successful download it will start own mini terminal (option ``-t``) like CZ.NIC mox-imager.

docs/plat/marvell/index.rst

@@ -6,6 +6,7 @@ Marvell
    :caption: Contents
 
    armada/build
+   armada/uart-booting
    armada/porting
    armada/misc/mvebu-a8k-addr-map
    armada/misc/mvebu-amb