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-rw-r--r--Documentation/boards/bcm2835.rst10
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@@ -30,5 +30,15 @@ Raspberry Pi
6. Turn board's power on.
+VideoCore firmware creates a device tree based on the entries in ``config.txt``. This file is available to the Barebox environment in the file ``/vc.dtb``. For example, to boot a kernel shipped with Raspbian::
+
+ bootm -o /vc.dtb /boot/kernel7.img
+
+VideoCore device tree also contains the kernel command-line that is constructed from ``cmdline.txt`` and other parameters internally determined by the VideoCore firmware. Normally in Barebox this command-line gets overwritten on boot by the Linux bootargs (see :ref:`booting_linux`).
+
+The original command-line from VideoCore device tree is available to the Barebox environment in the ``vc.bootargs`` global variable. For example, to append it to the Linux bootargs::
+
+ global linux.bootargs.vc="$global.vc.bootargs"
+
.. _Raspberry Pi firmware: https://codeload.github.com/raspberrypi/firmware/zip/80e1fbeb78f9df06701d28c0ed3a3060a3f557ef
.. _documentation for config.txt: https://www.raspberrypi.org/documentation/configuration/config-txt/