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Abhay Salunke6c54c282005-09-06 15:17:14 -07001Purpose:
2Demonstrate the usage of the new open sourced rbu (Remote BIOS Update) driver
3for updating BIOS images on Dell servers and desktops.
4
5Scope:
6This document discusses the functionality of the rbu driver only.
7It does not cover the support needed from aplications to enable the BIOS to
8update itself with the image downloaded in to the memory.
9
10Overview:
11This driver works with Dell OpenManage or Dell Update Packages for updating
12the BIOS on Dell servers (starting from servers sold since 1999), desktops
13and notebooks (starting from those sold in 2005).
14Please go to http://support.dell.com register and you can find info on
15OpenManage and Dell Update packages (DUP).
Abhay Salunkee61c0e32005-09-16 19:28:04 -070016Libsmbios can also be used to update BIOS on Dell systems go to
17http://linux.dell.com/libsmbios/ for details.
Abhay Salunke6c54c282005-09-06 15:17:14 -070018
19Dell_RBU driver supports BIOS update using the monilothic image and packetized
20image methods. In case of moniolithic the driver allocates a contiguous chunk
21of physical pages having the BIOS image. In case of packetized the app
22using the driver breaks the image in to packets of fixed sizes and the driver
23would place each packet in contiguous physical memory. The driver also
24maintains a link list of packets for reading them back.
25If the dell_rbu driver is unloaded all the allocated memory is freed.
26
Abhay Salunkee61c0e32005-09-16 19:28:04 -070027The rbu driver needs to have an application (as mentioned above)which will
28inform the BIOS to enable the update in the next system reboot.
Abhay Salunke6c54c282005-09-06 15:17:14 -070029
30The user should not unload the rbu driver after downloading the BIOS image
31or updating.
32
33The driver load creates the following directories under the /sys file system.
34/sys/class/firmware/dell_rbu/loading
35/sys/class/firmware/dell_rbu/data
36/sys/devices/platform/dell_rbu/image_type
37/sys/devices/platform/dell_rbu/data
38
39The driver supports two types of update mechanism; monolithic and packetized.
40These update mechanism depends upon the BIOS currently running on the system.
41Most of the Dell systems support a monolithic update where the BIOS image is
42copied to a single contiguous block of physical memory.
43In case of packet mechanism the single memory can be broken in smaller chuks
44of contiguous memory and the BIOS image is scattered in these packets.
45
46By default the driver uses monolithic memory for the update type. This can be
Abhay Salunkee61c0e32005-09-16 19:28:04 -070047changed to packets during the driver load time by specifying the load
Abhay Salunke6c54c282005-09-06 15:17:14 -070048parameter image_type=packet. This can also be changed later as below
49echo packet > /sys/devices/platform/dell_rbu/image_type
Abhay Salunkee61c0e32005-09-16 19:28:04 -070050Also echoing either mono ,packet or init in to image_type will free up the
51memory allocated by the driver.
Abhay Salunke6c54c282005-09-06 15:17:14 -070052
53Do the steps below to download the BIOS image.
541) echo 1 > /sys/class/firmware/dell_rbu/loading
552) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
563) echo 0 > /sys/class/firmware/dell_rbu/loading
57
58The /sys/class/firmware/dell_rbu/ entries will remain till the following is
59done.
Abhay Salunkee61c0e32005-09-16 19:28:04 -070060echo -1 > /sys/class/firmware/dell_rbu/loading.
Abhay Salunke6c54c282005-09-06 15:17:14 -070061Until this step is completed the drivr cannot be unloaded.
Abhay Salunkee61c0e32005-09-16 19:28:04 -070062If an user by accident executes steps 1 and 3 above without executing step 2;
63it will make the /sys/class/firmware/dell_rbu/ entries to disappear.
64The entries can be recreated by doing the following
65echo init > /sys/devices/platform/dell_rbu/image_type
66NOTE: echoing init in image_type does not change it original value.
Abhay Salunke6c54c282005-09-06 15:17:14 -070067
68Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
69read back the image downloaded. This is useful in case of packet update
70mechanism where the above steps 1,2,3 will repeated for every packet.
71By reading the /sys/devices/platform/dell_rbu/data file all packet data
72downloaded can be verified in a single file.
73The packets are arranged in this file one after the other in a FIFO order.
74
75NOTE:
76This driver requires a patch for firmware_class.c which has the addition
77of request_firmware_nowait_nohotplug function to wortk
78Also after updating the BIOS image an user mdoe application neeeds to execute
79code which message the BIOS update request to the BIOS. So on the next reboot
80the BIOS knows about the new image downloaded and it updates it self.
81Also don't unload the rbu drive if the image has to be updated.
82