75 lines
3.5 KiB
Text
75 lines
3.5 KiB
Text
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Purpose:
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Demonstrate the usage of the new open sourced rbu (Remote BIOS Update) driver
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for updating BIOS images on Dell servers and desktops.
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Scope:
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This document discusses the functionality of the rbu driver only.
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It does not cover the support needed from aplications to enable the BIOS to
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update itself with the image downloaded in to the memory.
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Overview:
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This driver works with Dell OpenManage or Dell Update Packages for updating
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the BIOS on Dell servers (starting from servers sold since 1999), desktops
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and notebooks (starting from those sold in 2005).
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Please go to http://support.dell.com register and you can find info on
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OpenManage and Dell Update packages (DUP).
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Dell_RBU driver supports BIOS update using the monilothic image and packetized
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image methods. In case of moniolithic the driver allocates a contiguous chunk
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of physical pages having the BIOS image. In case of packetized the app
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using the driver breaks the image in to packets of fixed sizes and the driver
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would place each packet in contiguous physical memory. The driver also
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maintains a link list of packets for reading them back.
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If the dell_rbu driver is unloaded all the allocated memory is freed.
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The rbu driver needs to have an application which will inform the BIOS to
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enable the update in the next system reboot.
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The user should not unload the rbu driver after downloading the BIOS image
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or updating.
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The driver load creates the following directories under the /sys file system.
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/sys/class/firmware/dell_rbu/loading
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/sys/class/firmware/dell_rbu/data
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/sys/devices/platform/dell_rbu/image_type
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/sys/devices/platform/dell_rbu/data
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The driver supports two types of update mechanism; monolithic and packetized.
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These update mechanism depends upon the BIOS currently running on the system.
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Most of the Dell systems support a monolithic update where the BIOS image is
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copied to a single contiguous block of physical memory.
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In case of packet mechanism the single memory can be broken in smaller chuks
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of contiguous memory and the BIOS image is scattered in these packets.
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By default the driver uses monolithic memory for the update type. This can be
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changed to contiguous during the driver load time by specifying the load
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parameter image_type=packet. This can also be changed later as below
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echo packet > /sys/devices/platform/dell_rbu/image_type
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Do the steps below to download the BIOS image.
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1) echo 1 > /sys/class/firmware/dell_rbu/loading
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2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data
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3) echo 0 > /sys/class/firmware/dell_rbu/loading
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The /sys/class/firmware/dell_rbu/ entries will remain till the following is
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done.
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echo -1 > /sys/class/firmware/dell_rbu/loading
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Until this step is completed the drivr cannot be unloaded.
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Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
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read back the image downloaded. This is useful in case of packet update
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mechanism where the above steps 1,2,3 will repeated for every packet.
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By reading the /sys/devices/platform/dell_rbu/data file all packet data
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downloaded can be verified in a single file.
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The packets are arranged in this file one after the other in a FIFO order.
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NOTE:
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This driver requires a patch for firmware_class.c which has the addition
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of request_firmware_nowait_nohotplug function to wortk
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Also after updating the BIOS image an user mdoe application neeeds to execute
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code which message the BIOS update request to the BIOS. So on the next reboot
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the BIOS knows about the new image downloaded and it updates it self.
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Also don't unload the rbu drive if the image has to be updated.
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