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Commit 58ef0e5b authored May 17, 2017 by Mauro Carvalho Chehab Committed by Jonathan Corbet Jul 14, 2017

dell_rbu.txt: standardize document format



Each text file under Documentation follows a different
format. Some doesn't even have titles!

Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx.

Currently, the document is completely unformatted. Add
titles, do indentation, mark literal blocks.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

parent 998ff0b5

Documentation/dell_rbu.txt

+56 −25

Original line number	Original line	Diff line number	Diff line
	Purpose:		=============================================================
	Demonstrate the usage of the new open sourced rbu (Remote BIOS Update) driver		Usage of the new open sourced rbu (Remote BIOS Update) driver
			=============================================================

			Purpose
			=======

			Document demonstrating the use of the Dell Remote BIOS Update driver.
	for updating BIOS images on Dell servers and desktops.		for updating BIOS images on Dell servers and desktops.

	Scope:		Scope
			=====

	This document discusses the functionality of the rbu driver only.		This document discusses the functionality of the rbu driver only.
	It does not cover the support needed from applications to enable the BIOS to		It does not cover the support needed from applications to enable the BIOS to
	update itself with the image downloaded in to the memory.		update itself with the image downloaded in to the memory.

	Overview:		Overview
			========

	This driver works with Dell OpenManage or Dell Update Packages for updating		This driver works with Dell OpenManage or Dell Update Packages for updating
	the BIOS on Dell servers (starting from servers sold since 1999), desktops		the BIOS on Dell servers (starting from servers sold since 1999), desktops
	and notebooks (starting from those sold in 2005).		and notebooks (starting from those sold in 2005).

	Please go to http://support.dell.com register and you can find info on		Please go to http://support.dell.com register and you can find info on
	OpenManage and Dell Update packages (DUP).		OpenManage and Dell Update packages (DUP).

	Libsmbios can also be used to update BIOS on Dell systems go to		Libsmbios can also be used to update BIOS on Dell systems go to
	http://linux.dell.com/libsmbios/ for details.		http://linux.dell.com/libsmbios/ for details.

	@@ -22,6 +34,7 @@ of physical pages having the BIOS image. In case of packetized the app
	using the driver breaks the image in to packets of fixed sizes and the driver		using the driver breaks the image in to packets of fixed sizes and the driver
	would place each packet in contiguous physical memory. The driver also		would place each packet in contiguous physical memory. The driver also
	maintains a link list of packets for reading them back.		maintains a link list of packets for reading them back.

	If the dell_rbu driver is unloaded all the allocated memory is freed.		If the dell_rbu driver is unloaded all the allocated memory is freed.

	The rbu driver needs to have an application (as mentioned above)which will		The rbu driver needs to have an application (as mentioned above)which will
	@@ -30,7 +43,8 @@ inform the BIOS to enable the update in the next system reboot.
	The user should not unload the rbu driver after downloading the BIOS image		The user should not unload the rbu driver after downloading the BIOS image
	or updating.		or updating.

	The driver load creates the following directories under the /sys file system.		The driver load creates the following directories under the /sys file system::

	/sys/class/firmware/dell_rbu/loading		/sys/class/firmware/dell_rbu/loading
	/sys/class/firmware/dell_rbu/data		/sys/class/firmware/dell_rbu/data
	/sys/devices/platform/dell_rbu/image_type		/sys/devices/platform/dell_rbu/image_type
	@@ -41,17 +55,21 @@ The driver supports two types of update mechanism; monolithic and packetized.
	These update mechanism depends upon the BIOS currently running on the system.		These update mechanism depends upon the BIOS currently running on the system.
	Most of the Dell systems support a monolithic update where the BIOS image is		Most of the Dell systems support a monolithic update where the BIOS image is
	copied to a single contiguous block of physical memory.		copied to a single contiguous block of physical memory.

	In case of packet mechanism the single memory can be broken in smaller chunks		In case of packet mechanism the single memory can be broken in smaller chunks
	of contiguous memory and the BIOS image is scattered in these packets.		of contiguous memory and the BIOS image is scattered in these packets.

	By default the driver uses monolithic memory for the update type. This can be		By default the driver uses monolithic memory for the update type. This can be
	changed to packets during the driver load time by specifying the load		changed to packets during the driver load time by specifying the load
	parameter image_type=packet. This can also be changed later as below		parameter image_type=packet. This can also be changed later as below::

	echo packet > /sys/devices/platform/dell_rbu/image_type		echo packet > /sys/devices/platform/dell_rbu/image_type

	In packet update mode the packet size has to be given before any packets can		In packet update mode the packet size has to be given before any packets can
	be downloaded. It is done as below		be downloaded. It is done as below::

	echo XXXX > /sys/devices/platform/dell_rbu/packet_size		echo XXXX > /sys/devices/platform/dell_rbu/packet_size

	In the packet update mechanism, the user needs to create a new file having		In the packet update mechanism, the user needs to create a new file having
	packets of data arranged back to back. It can be done as follows		packets of data arranged back to back. It can be done as follows
	The user creates packets header, gets the chunk of the BIOS image and		The user creates packets header, gets the chunk of the BIOS image and
	@@ -60,39 +78,52 @@ added together should match the specified packet_size. This makes one
	packet, the user needs to create more such packets out of the entire BIOS		packet, the user needs to create more such packets out of the entire BIOS
	image file and then arrange all these packets back to back in to one single		image file and then arrange all these packets back to back in to one single
	file.		file.

	This file is then copied to /sys/class/firmware/dell_rbu/data.		This file is then copied to /sys/class/firmware/dell_rbu/data.
	Once this file gets to the driver, the driver extracts packet_size data from		Once this file gets to the driver, the driver extracts packet_size data from
	the file and spreads it across the physical memory in contiguous packet_sized		the file and spreads it across the physical memory in contiguous packet_sized
	space.		space.

	This method makes sure that all the packets get to the driver in a single operation.		This method makes sure that all the packets get to the driver in a single operation.

	In monolithic update the user simply get the BIOS image (.hdr file) and copies		In monolithic update the user simply get the BIOS image (.hdr file) and copies
	to the data file as is without any change to the BIOS image itself.		to the data file as is without any change to the BIOS image itself.

	Do the steps below to download the BIOS image.		Do the steps below to download the BIOS image.

	1) echo 1 > /sys/class/firmware/dell_rbu/loading		1) echo 1 > /sys/class/firmware/dell_rbu/loading
	2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data		2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
	3) echo 0 > /sys/class/firmware/dell_rbu/loading		3) echo 0 > /sys/class/firmware/dell_rbu/loading

	The /sys/class/firmware/dell_rbu/ entries will remain till the following is		The /sys/class/firmware/dell_rbu/ entries will remain till the following is
	done.		done.

			::

	echo -1 > /sys/class/firmware/dell_rbu/loading		echo -1 > /sys/class/firmware/dell_rbu/loading

	Until this step is completed the driver cannot be unloaded.		Until this step is completed the driver cannot be unloaded.

	Also echoing either mono, packet or init in to image_type will free up the		Also echoing either mono, packet or init in to image_type will free up the
	memory allocated by the driver.		memory allocated by the driver.

	If a user by accident executes steps 1 and 3 above without executing step 2;		If a user by accident executes steps 1 and 3 above without executing step 2;
	it will make the /sys/class/firmware/dell_rbu/ entries disappear.		it will make the /sys/class/firmware/dell_rbu/ entries disappear.
	The entries can be recreated by doing the following
			The entries can be recreated by doing the following::

	echo init > /sys/devices/platform/dell_rbu/image_type		echo init > /sys/devices/platform/dell_rbu/image_type
	NOTE: echoing init in image_type does not change it original value.
			.. note:: echoing init in image_type does not change it original value.

	Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to		Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
	read back the image downloaded.		read back the image downloaded.

	NOTE:		.. note::

	This driver requires a patch for firmware_class.c which has the modified		This driver requires a patch for firmware_class.c which has the modified
	request_firmware_nowait function.		request_firmware_nowait function.

	Also after updating the BIOS image a user mode application needs to execute		Also after updating the BIOS image a user mode application needs to execute
	code which sends the BIOS update request to the BIOS. So on the next reboot		code which sends the BIOS update request to the BIOS. So on the next reboot
	the BIOS knows about the new image downloaded and it updates itself.		the BIOS knows about the new image downloaded and it updates itself.