Documentation/admin-guide/dell_rbu.rst
Source file repositories/reference/linux-study-clean/Documentation/admin-guide/dell_rbu.rst
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- System
- Linux kernel
- Corpus path
Documentation/admin-guide/dell_rbu.rst- Extension
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- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
=========================================
Dell Remote BIOS Update driver (dell_rbu)
=========================================
Purpose
=======
Document demonstrating the use of the Dell 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
https://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::
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.