mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-30 16:13:54 +08:00
992caacf11
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'N'-'P'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
101 lines
4.9 KiB
Plaintext
101 lines
4.9 KiB
Plaintext
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 applications 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).
|
|
Libsmbios can also be used to update BIOS on Dell systems go to
|
|
http://linux.dell.com/libsmbios/ for details.
|
|
|
|
Dell_RBU driver supports BIOS update using the monolithic image and packetized
|
|
image methods. In case of monolithic 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 (as mentioned above)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
|
|
/sys/devices/platform/dell_rbu/packet_size
|
|
|
|
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 chunks
|
|
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 packets 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
|
|
|
|
In packet update mode the packet size has to be given before any packets can
|
|
be downloaded. It is done as below
|
|
echo XXXX > /sys/devices/platform/dell_rbu/packet_size
|
|
In the packet update mechanism, the user needs to create a new file having
|
|
packets of data arranged back to back. It can be done as follows
|
|
The user creates packets header, gets the chunk of the BIOS image and
|
|
places it next to the packetheader; now, the packetheader + BIOS image chunk
|
|
added together should match the specified packet_size. This makes one
|
|
packet, the user needs to create more such packets out of the entire BIOS
|
|
image file and then arrange all these packets back to back in to one single
|
|
file.
|
|
This file is then copied to /sys/class/firmware/dell_rbu/data.
|
|
Once this file gets to the driver, the driver extracts packet_size data from
|
|
the file and spreads it accross the physical memory in contiguous packet_sized
|
|
space.
|
|
This method makes sure that all the packets get to the driver in a single operation.
|
|
|
|
In monolithic update the user simply get the BIOS image (.hdr file) and copies
|
|
to the data file as is without any change to the BIOS image itself.
|
|
|
|
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 driver cannot be unloaded.
|
|
Also echoing either mono ,packet or init in to image_type will free up the
|
|
memory allocated by the driver.
|
|
|
|
If an user by accident executes steps 1 and 3 above without executing step 2;
|
|
it will make the /sys/class/firmware/dell_rbu/ entries to disappear.
|
|
The entries can be recreated by doing the following
|
|
echo init > /sys/devices/platform/dell_rbu/image_type
|
|
NOTE: echoing init in image_type does not change it original value.
|
|
|
|
Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
|
|
read back the image downloaded.
|
|
|
|
NOTE:
|
|
This driver requires a patch for firmware_class.c which has the modified
|
|
request_firmware_nowait function.
|
|
Also after updating the BIOS image a user mode application needs to execute
|
|
code which sends the BIOS update request to the BIOS. So on the next reboot
|
|
the BIOS knows about the new image downloaded and it updates itself.
|
|
Also don't unload the rbu driver if the image has to be updated.
|
|
|