|Demonstrate the usage of the new open sourced rbu (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.
|Dell_RBU driver supports BIOS update using the monolithic image and packetized
|image methods. In case of monolithic the driver allocates a contiguous chunk
|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
|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 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
|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
|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
|places it next to the packetheader; now, the packetheader + BIOS image chunk
|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
|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.
|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.