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2 Dell Remote BIOS Update driver (dell_rbu) 2 Dell Remote BIOS Update driver (dell_rbu)
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4 4
5 Purpose 5 Purpose
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7 7
8 Document demonstrating the use of the Dell Rem 8 Document demonstrating the use of the Dell Remote BIOS Update driver
9 for updating BIOS images on Dell servers and d 9 for updating BIOS images on Dell servers and desktops.
10 10
11 Scope 11 Scope
12 ===== 12 =====
13 13
14 This document discusses the functionality of t 14 This document discusses the functionality of the rbu driver only.
15 It does not cover the support needed from appl 15 It does not cover the support needed from applications to enable the BIOS to
16 update itself with the image downloaded in to 16 update itself with the image downloaded in to the memory.
17 17
18 Overview 18 Overview
19 ======== 19 ========
20 20
21 This driver works with Dell OpenManage or Dell 21 This driver works with Dell OpenManage or Dell Update Packages for updating
22 the BIOS on Dell servers (starting from server 22 the BIOS on Dell servers (starting from servers sold since 1999), desktops
23 and notebooks (starting from those sold in 200 23 and notebooks (starting from those sold in 2005).
24 24
25 Please go to http://support.dell.com register 25 Please go to http://support.dell.com register and you can find info on
26 OpenManage and Dell Update packages (DUP). 26 OpenManage and Dell Update packages (DUP).
27 27
28 Libsmbios can also be used to update BIOS on D 28 Libsmbios can also be used to update BIOS on Dell systems go to
29 https://linux.dell.com/libsmbios/ for details. 29 https://linux.dell.com/libsmbios/ for details.
30 30
31 Dell_RBU driver supports BIOS update using the 31 Dell_RBU driver supports BIOS update using the monolithic image and packetized
32 image methods. In case of monolithic the drive 32 image methods. In case of monolithic the driver allocates a contiguous chunk
33 of physical pages having the BIOS image. In ca 33 of physical pages having the BIOS image. In case of packetized the app
34 using the driver breaks the image in to packet 34 using the driver breaks the image in to packets of fixed sizes and the driver
35 would place each packet in contiguous physical 35 would place each packet in contiguous physical memory. The driver also
36 maintains a link list of packets for reading t 36 maintains a link list of packets for reading them back.
37 37
38 If the dell_rbu driver is unloaded all the all 38 If the dell_rbu driver is unloaded all the allocated memory is freed.
39 39
40 The rbu driver needs to have an application (a 40 The rbu driver needs to have an application (as mentioned above) which will
41 inform the BIOS to enable the update in the ne 41 inform the BIOS to enable the update in the next system reboot.
42 42
43 The user should not unload the rbu driver afte 43 The user should not unload the rbu driver after downloading the BIOS image
44 or updating. 44 or updating.
45 45
46 The driver load creates the following director 46 The driver load creates the following directories under the /sys file system::
47 47
48 /sys/class/firmware/dell_rbu/loading 48 /sys/class/firmware/dell_rbu/loading
49 /sys/class/firmware/dell_rbu/data 49 /sys/class/firmware/dell_rbu/data
50 /sys/devices/platform/dell_rbu/image_t 50 /sys/devices/platform/dell_rbu/image_type
51 /sys/devices/platform/dell_rbu/data 51 /sys/devices/platform/dell_rbu/data
52 /sys/devices/platform/dell_rbu/packet_ 52 /sys/devices/platform/dell_rbu/packet_size
53 53
54 The driver supports two types of update mechan 54 The driver supports two types of update mechanism; monolithic and packetized.
55 These update mechanism depends upon the BIOS c 55 These update mechanism depends upon the BIOS currently running on the system.
56 Most of the Dell systems support a monolithic 56 Most of the Dell systems support a monolithic update where the BIOS image is
57 copied to a single contiguous block of physica 57 copied to a single contiguous block of physical memory.
58 58
59 In case of packet mechanism the single memory 59 In case of packet mechanism the single memory can be broken in smaller chunks
60 of contiguous memory and the BIOS image is sca 60 of contiguous memory and the BIOS image is scattered in these packets.
61 61
62 By default the driver uses monolithic memory f 62 By default the driver uses monolithic memory for the update type. This can be
63 changed to packets during the driver load time 63 changed to packets during the driver load time by specifying the load
64 parameter image_type=packet. This can also be 64 parameter image_type=packet. This can also be changed later as below::
65 65
66 echo packet > /sys/devices/platform/de 66 echo packet > /sys/devices/platform/dell_rbu/image_type
67 67
68 In packet update mode the packet size has to b 68 In packet update mode the packet size has to be given before any packets can
69 be downloaded. It is done as below:: 69 be downloaded. It is done as below::
70 70
71 echo XXXX > /sys/devices/platform/dell 71 echo XXXX > /sys/devices/platform/dell_rbu/packet_size
72 72
73 In the packet update mechanism, the user needs 73 In the packet update mechanism, the user needs to create a new file having
74 packets of data arranged back to back. It can 74 packets of data arranged back to back. It can be done as follows:
75 The user creates packets header, gets the chun 75 The user creates packets header, gets the chunk of the BIOS image and
76 places it next to the packetheader; now, the p 76 places it next to the packetheader; now, the packetheader + BIOS image chunk
77 added together should match the specified pack 77 added together should match the specified packet_size. This makes one
78 packet, the user needs to create more such pac 78 packet, the user needs to create more such packets out of the entire BIOS
79 image file and then arrange all these packets 79 image file and then arrange all these packets back to back in to one single
80 file. 80 file.
81 81
82 This file is then copied to /sys/class/firmwar 82 This file is then copied to /sys/class/firmware/dell_rbu/data.
83 Once this file gets to the driver, the driver 83 Once this file gets to the driver, the driver extracts packet_size data from
84 the file and spreads it across the physical me 84 the file and spreads it across the physical memory in contiguous packet_sized
85 space. 85 space.
86 86
87 This method makes sure that all the packets ge 87 This method makes sure that all the packets get to the driver in a single operation.
88 88
89 In monolithic update the user simply get the B 89 In monolithic update the user simply get the BIOS image (.hdr file) and copies
90 to the data file as is without any change to t 90 to the data file as is without any change to the BIOS image itself.
91 91
92 Do the steps below to download the BIOS image. 92 Do the steps below to download the BIOS image.
93 93
94 1) echo 1 > /sys/class/firmware/dell_rbu/loadi 94 1) echo 1 > /sys/class/firmware/dell_rbu/loading
95 2) cp bios_image.hdr /sys/class/firmware/dell_ 95 2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
96 3) echo 0 > /sys/class/firmware/dell_rbu/loadi 96 3) echo 0 > /sys/class/firmware/dell_rbu/loading
97 97
98 The /sys/class/firmware/dell_rbu/ entries will 98 The /sys/class/firmware/dell_rbu/ entries will remain till the following is
99 done. 99 done.
100 100
101 :: 101 ::
102 102
103 echo -1 > /sys/class/firmware/dell_rbu 103 echo -1 > /sys/class/firmware/dell_rbu/loading
104 104
105 Until this step is completed the driver cannot 105 Until this step is completed the driver cannot be unloaded.
106 106
107 Also echoing either mono, packet or init in to 107 Also echoing either mono, packet or init in to image_type will free up the
108 memory allocated by the driver. 108 memory allocated by the driver.
109 109
110 If a user by accident executes steps 1 and 3 a 110 If a user by accident executes steps 1 and 3 above without executing step 2;
111 it will make the /sys/class/firmware/dell_rbu/ 111 it will make the /sys/class/firmware/dell_rbu/ entries disappear.
112 112
113 The entries can be recreated by doing the foll 113 The entries can be recreated by doing the following::
114 114
115 echo init > /sys/devices/platform/dell 115 echo init > /sys/devices/platform/dell_rbu/image_type
116 116
117 .. note:: echoing init in image_type does not 117 .. note:: echoing init in image_type does not change its original value.
118 118
119 Also the driver provides /sys/devices/platform 119 Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
120 read back the image downloaded. 120 read back the image downloaded.
121 121
122 .. note:: 122 .. note::
123 123
124 After updating the BIOS image a user mode a 124 After updating the BIOS image a user mode application needs to execute
125 code which sends the BIOS update request to 125 code which sends the BIOS update request to the BIOS. So on the next reboot
126 the BIOS knows about the new image download 126 the BIOS knows about the new image downloaded and it updates itself.
127 Also don't unload the rbu driver if the ima 127 Also don't unload the rbu driver if the image has to be updated.
128 128
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