[PATCH] dell_rbu: new Dell BIOS update driver

Remote BIOS Update driver for updating BIOS images on Dell servers and
desktops.  See dell_rbu.txt for details.
Signed-off-by: Abhay Salunke <Abhay_Salunke@dell.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/dell_rbu.txt

+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.
+

drivers/firmware/Kconfig

@@ -58,4 +58,13 @@ config EFI_PCDP
 
 	  See <http://www.dig64.org/specifications/DIG64_HCDPv20_042804.pdf>
 
+config DELL_RBU
+	tristate "BIOS update support for DELL systems via sysfs"
+	select FW_LOADER
+	help
+	 Say m if you want to have the option of updating the BIOS for your
+	 DELL system. Note you need a Dell OpenManage or Dell Update package (DUP)
+	 supporting application to comunicate with the BIOS regarding the new
+	 image for the image update to take effect.
+	 See <file:Documentation/dell_rbu.txt> for more details on the driver.
 endmenu

drivers/firmware/Makefile

@@ -4,3 +4,4 @@
 obj-$(CONFIG_EDD)             	+= edd.o
 obj-$(CONFIG_EFI_VARS)		+= efivars.o
 obj-$(CONFIG_EFI_PCDP)		+= pcdp.o
+obj-$(CONFIG_DELL_RBU)          += dell_rbu.o