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diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt new file mode 100644 index 00000000000..bcfa5c35036 --- /dev/null +++ b/Documentation/dell_rbu.txt @@ -0,0 +1,74 @@ +Purpose: +Demonstrate the usage of the new open sourced rbu (Remote BIOS Update) driver +for updating BIOS images on Dell servers and desktops. + +Scope: +This document discusses the functionality of the rbu driver only. +It does not cover the support needed from aplications to enable the BIOS to +update itself with the image downloaded in to the memory. + +Overview: +This driver works with Dell OpenManage or Dell Update Packages for updating +the BIOS on Dell servers (starting from servers sold since 1999), desktops +and notebooks (starting from those sold in 2005). +Please go to http://support.dell.com register and you can find info on +OpenManage and Dell Update packages (DUP). + +Dell_RBU driver supports BIOS update using the monilothic image and packetized +image methods. In case of moniolithic the driver allocates a contiguous chunk +of physical pages having the BIOS image. In case of packetized the app +using the driver breaks the image in to packets of fixed sizes and the driver +would place each packet in contiguous physical memory. The driver also +maintains a link list of packets for reading them back. +If the dell_rbu driver is unloaded all the allocated memory is freed. + +The rbu driver needs to have an application which will inform the BIOS to +enable the update in the next system reboot. + +The user should not unload the rbu driver after downloading the BIOS image +or updating. + +The driver load creates the following directories under the /sys file system. +/sys/class/firmware/dell_rbu/loading +/sys/class/firmware/dell_rbu/data +/sys/devices/platform/dell_rbu/image_type +/sys/devices/platform/dell_rbu/data + +The driver supports two types of update mechanism; monolithic and packetized. +These update mechanism depends upon the BIOS currently running on the system. +Most of the Dell systems support a monolithic update where the BIOS image is +copied to a single contiguous block of physical memory. +In case of packet mechanism the single memory can be broken in smaller chuks +of contiguous memory and the BIOS image is scattered in these packets. + +By default the driver uses monolithic memory for the update type. This can be +changed to contiguous during the driver load time by specifying the load +parameter image_type=packet. This can also be changed later as below +echo packet > /sys/devices/platform/dell_rbu/image_type + +Do the steps below to download the BIOS image. +1) echo 1 > /sys/class/firmware/dell_rbu/loading +2) cp bios_image.hdr /sys/class/firmware/dell_rbu/data +3) echo 0 > /sys/class/firmware/dell_rbu/loading + +The /sys/class/firmware/dell_rbu/ entries will remain till the following is +done. +echo -1 > /sys/class/firmware/dell_rbu/loading + +Until this step is completed the drivr cannot be unloaded. + +Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to +read back the image downloaded. This is useful in case of packet update +mechanism where the above steps 1,2,3 will repeated for every packet. +By reading the /sys/devices/platform/dell_rbu/data file all packet data +downloaded can be verified in a single file. +The packets are arranged in this file one after the other in a FIFO order. + +NOTE: +This driver requires a patch for firmware_class.c which has the addition +of request_firmware_nowait_nohotplug function to wortk +Also after updating the BIOS image an user mdoe application neeeds to execute +code which message the BIOS update request to the BIOS. So on the next reboot +the BIOS knows about the new image downloaded and it updates it self. +Also don't unload the rbu drive if the image has to be updated. + |