[PATCH 29/29] dell_rbu.txt: standardize document format
From: Mauro Carvalho Chehab
Date: Thu May 18 2017 - 21:26:54 EST
From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Documentation/dell_rbu.txt | 81 ++++++++++++++++++++++++++++++++--------------
1 file changed, 56 insertions(+), 25 deletions(-)
diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt
index d262e22bddec..0fdb6aa2704c 100644
@@ -1,18 +1,30 @@
-Demonstrate the usage of the new open sourced rbu (Remote BIOS Update) driver
+Usage of the new open sourced rbu (Remote BIOS Update) driver
+Document demonstrating the use of the Dell Remote BIOS Update driver.
for updating BIOS images on Dell servers and desktops.
This document discusses the functionality of the rbu driver only.
It does not cover the support needed from applications to enable the BIOS to
update itself with the image downloaded in to the memory.
This driver works with Dell OpenManage or Dell Update Packages for updating
the BIOS on Dell servers (starting from servers sold since 1999), desktops
and notebooks (starting from those sold in 2005).
Please go to http://support.dell.com register and you can find info on
OpenManage and Dell Update packages (DUP).
Libsmbios can also be used to update BIOS on Dell systems go to
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
would place each packet in contiguous physical memory. The driver also
maintains a link list of packets for reading them back.
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
@@ -30,28 +43,33 @@ 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 driver load creates the following directories under the /sys file system.
+The driver load creates the following directories under the /sys file system::
The driver supports two types of update mechanism; monolithic and packetized.
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
copied to a single contiguous block of physical memory.
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.
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
-parameter image_type=packet. This can also be changed later as below
-echo packet > /sys/devices/platform/dell_rbu/image_type
+parameter image_type=packet. This can also be changed later as below::
+ echo packet > /sys/devices/platform/dell_rbu/image_type
In packet update mode the packet size has to be given before any packets can
-be downloaded. It is done as below
-echo XXXX > /sys/devices/platform/dell_rbu/packet_size
+be downloaded. It is done as below::
+ echo XXXX > /sys/devices/platform/dell_rbu/packet_size
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
The user creates packets header, gets the chunk of the BIOS image and
@@ -60,41 +78,54 @@ 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
image file and then arrange all these packets back to back in to one single
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
the file and spreads it across the physical memory in contiguous packet_sized
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
to the data file as is without any change to the BIOS image itself.
Do the steps below to download the BIOS image.
1) echo 1 > /sys/class/firmware/dell_rbu/loading
2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
3) echo 0 > /sys/class/firmware/dell_rbu/loading
The /sys/class/firmware/dell_rbu/ entries will remain till the following is
-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.
Also echoing either mono, packet or init in to image_type will free up the
memory allocated by the driver.
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.
-The entries can be recreated by doing the following
-echo init > /sys/devices/platform/dell_rbu/image_type
-NOTE: echoing init in image_type does not change it original value.
+The entries can be recreated by doing the following::
+ echo init > /sys/devices/platform/dell_rbu/image_type
+.. 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
read back the image downloaded.
-This driver requires a patch for firmware_class.c which has the modified
-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
-the BIOS knows about the new image downloaded and it updates itself.
-Also don't unload the rbu driver if the image has to be updated.
+ This driver requires a patch for firmware_class.c which has the modified
+ request_firmware_nowait function.
+ 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
+ the BIOS knows about the new image downloaded and it updates itself.
+ Also don't unload the rbu driver if the image has to be updated.