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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.
Matt LaPlante3f6dee92006-10-03 22:45:33 +02007It does not cover the support needed from applications to enable the BIOS to
Abhay Salunke6c54c282005-09-06 15:17:14 -07008update 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
Matt LaPlante2fe0ae72006-10-03 22:50:39 +020019Dell_RBU driver supports BIOS update using the monolithic image and packetized
20image methods. In case of monolithic the driver allocates a contiguous chunk
Abhay Salunke6c54c282005-09-06 15:17:14 -070021of 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
Abhay Salunkead6ce872005-10-11 08:29:02 -070038/sys/devices/platform/dell_rbu/packet_size
Abhay Salunke6c54c282005-09-06 15:17:14 -070039
40The driver supports two types of update mechanism; monolithic and packetized.
41These update mechanism depends upon the BIOS currently running on the system.
42Most of the Dell systems support a monolithic update where the BIOS image is
43copied to a single contiguous block of physical memory.
Matt LaPlante6c28f2c2006-10-03 22:46:31 +020044In case of packet mechanism the single memory can be broken in smaller chunks
Abhay Salunke6c54c282005-09-06 15:17:14 -070045of contiguous memory and the BIOS image is scattered in these packets.
46
47By default the driver uses monolithic memory for the update type. This can be
Abhay Salunkee61c0e32005-09-16 19:28:04 -070048changed to packets during the driver load time by specifying the load
Abhay Salunke6c54c282005-09-06 15:17:14 -070049parameter image_type=packet. This can also be changed later as below
50echo packet > /sys/devices/platform/dell_rbu/image_type
Abhay Salunkead6ce872005-10-11 08:29:02 -070051
52In packet update mode the packet size has to be given before any packets can
53be downloaded. It is done as below
54echo XXXX > /sys/devices/platform/dell_rbu/packet_size
Matt LaPlante992caac2006-10-03 22:52:05 +020055In the packet update mechanism, the user needs to create a new file having
Abhay Salunkead6ce872005-10-11 08:29:02 -070056packets of data arranged back to back. It can be done as follows
57The user creates packets header, gets the chunk of the BIOS image and
Matt LaPlantea2ffd272006-10-03 22:49:15 +020058places it next to the packetheader; now, the packetheader + BIOS image chunk
59added together should match the specified packet_size. This makes one
Abhay Salunkead6ce872005-10-11 08:29:02 -070060packet, the user needs to create more such packets out of the entire BIOS
61image file and then arrange all these packets back to back in to one single
62file.
63This file is then copied to /sys/class/firmware/dell_rbu/data.
64Once this file gets to the driver, the driver extracts packet_size data from
65the file and spreads it accross the physical memory in contiguous packet_sized
66space.
67This method makes sure that all the packets get to the driver in a single operation.
68
69In monolithic update the user simply get the BIOS image (.hdr file) and copies
70to the data file as is without any change to the BIOS image itself.
Abhay Salunke6c54c282005-09-06 15:17:14 -070071
72Do the steps below to download the BIOS image.
731) echo 1 > /sys/class/firmware/dell_rbu/loading
742) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
753) echo 0 > /sys/class/firmware/dell_rbu/loading
76
77The /sys/class/firmware/dell_rbu/ entries will remain till the following is
78done.
Abhay Salunkee61c0e32005-09-16 19:28:04 -070079echo -1 > /sys/class/firmware/dell_rbu/loading.
Abhay Salunkead6ce872005-10-11 08:29:02 -070080Until this step is completed the driver cannot be unloaded.
81Also echoing either mono ,packet or init in to image_type will free up the
82memory allocated by the driver.
83
Abhay Salunkee61c0e32005-09-16 19:28:04 -070084If an user by accident executes steps 1 and 3 above without executing step 2;
85it will make the /sys/class/firmware/dell_rbu/ entries to disappear.
86The entries can be recreated by doing the following
87echo init > /sys/devices/platform/dell_rbu/image_type
88NOTE: echoing init in image_type does not change it original value.
Abhay Salunke6c54c282005-09-06 15:17:14 -070089
90Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
Abhay Salunkead6ce872005-10-11 08:29:02 -070091read back the image downloaded.
Abhay Salunke6c54c282005-09-06 15:17:14 -070092
93NOTE:
Abhay Salunkead6ce872005-10-11 08:29:02 -070094This driver requires a patch for firmware_class.c which has the modified
95request_firmware_nowait function.
Matt LaPlante992caac2006-10-03 22:52:05 +020096Also after updating the BIOS image a user mode application needs to execute
97code which sends the BIOS update request to the BIOS. So on the next reboot
98the BIOS knows about the new image downloaded and it updates itself.
99Also don't unload the rbu driver if the image has to be updated.
Abhay Salunke6c54c282005-09-06 15:17:14 -0700100