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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).
16
17Dell_RBU driver supports BIOS update using the monilothic image and packetized
18image methods. In case of moniolithic the driver allocates a contiguous chunk
19of physical pages having the BIOS image. In case of packetized the app
20using the driver breaks the image in to packets of fixed sizes and the driver
21would place each packet in contiguous physical memory. The driver also
22maintains a link list of packets for reading them back.
23If the dell_rbu driver is unloaded all the allocated memory is freed.
24
25The rbu driver needs to have an application which will inform the BIOS to
26enable the update in the next system reboot.
27
28The user should not unload the rbu driver after downloading the BIOS image
29or updating.
30
31The driver load creates the following directories under the /sys file system.
32/sys/class/firmware/dell_rbu/loading
33/sys/class/firmware/dell_rbu/data
34/sys/devices/platform/dell_rbu/image_type
35/sys/devices/platform/dell_rbu/data
36
37The driver supports two types of update mechanism; monolithic and packetized.
38These update mechanism depends upon the BIOS currently running on the system.
39Most of the Dell systems support a monolithic update where the BIOS image is
40copied to a single contiguous block of physical memory.
41In case of packet mechanism the single memory can be broken in smaller chuks
42of contiguous memory and the BIOS image is scattered in these packets.
43
44By default the driver uses monolithic memory for the update type. This can be
45changed to contiguous during the driver load time by specifying the load
46parameter image_type=packet. This can also be changed later as below
47echo packet > /sys/devices/platform/dell_rbu/image_type
48
49Do the steps below to download the BIOS image.
501) echo 1 > /sys/class/firmware/dell_rbu/loading
512) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
523) echo 0 > /sys/class/firmware/dell_rbu/loading
53
54The /sys/class/firmware/dell_rbu/ entries will remain till the following is
55done.
56echo -1 > /sys/class/firmware/dell_rbu/loading
57
58Until this step is completed the drivr cannot be unloaded.
59
60Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
61read back the image downloaded. This is useful in case of packet update
62mechanism where the above steps 1,2,3 will repeated for every packet.
63By reading the /sys/devices/platform/dell_rbu/data file all packet data
64downloaded can be verified in a single file.
65The packets are arranged in this file one after the other in a FIFO order.
66
67NOTE:
68This driver requires a patch for firmware_class.c which has the addition
69of request_firmware_nowait_nohotplug function to wortk
70Also after updating the BIOS image an user mdoe application neeeds to execute
71code which message the BIOS update request to the BIOS. So on the next reboot
72the BIOS knows about the new image downloaded and it updates it self.
73Also don't unload the rbu drive if the image has to be updated.
74