Driver updating with linux

Updating drivers during installation

This section describes how to complete a driver update during the CentOS installation process.

This is an optional step of the installation process. CentOS Project recommends that you do not perform a driver update unless it is necessary.

Overview

CentOS supports drivers for many hardware devices but some newly-released drivers may not be supported. A driver update should only be performed if an unsupported driver prevents the installation from completing. Updating drivers during installation is typically only required to support a particular configuration. For example, installing drivers for a storage adapter card that provides access to your system’s storage devices.

Driver update disks may disable conflicting kernel drivers. In rare cases, unloading a kernel module may cause installation errors.

Types of driver update

Your hardware vendor or a trusted third party provides the driver update as an ISO image file. Once you receive the ISO image file, choose the type of driver update.

The recommended driver update method; a storage device (including a CD, DVD, or USB flash drive) labeled OEMDRV is physically connected to the system. If the OEMDRV storage device is present when the installation starts, it is treated as a driver update disk, and the installation program automatically loads its drivers.

The installation program prompts you to locate a driver update. You can use any local storage device with a label other than OEMDRV . The inst.dd boot option is specified when starting the installation. If you use this option without any parameters, the installation program displays all of the storage devices connected to the system, and prompts you to select a device that contains a driver update.

Manually specify a path to a driver update image or an RPM package. You can use any local storage device with a label other than OEMDRV , or a network location accessible from the installation system. The inst.dd=location boot option is specified when starting the installation, where location is the path to a driver update disk or ISO image. When you specify this option, the installation program attempts to load any driver updates found at the specified location. With manual driver updates, you can specify local storage devices, or a network location (HTTP, HTTPS or FTP server).

• You can use both inst.dd=location and inst.dd simultaneously, where location is the path to a driver update disk or ISO image. In this scenario, the installation program attempts to load any available driver updates from the location and also prompts you to select a device that contains the driver update.
• Initialize the network using the ip= option when loading a driver update from a network location.

On UEFI systems with the Secure Boot technology enabled, all drivers must be signed with a valid certificate. CentOS drivers are signed by one of CentOS Project’s private keys and authenticated by its corresponding public key in the kernel. If you load additional, separate drivers, verify that they are signed.

Preparing a driver update

This procedure describes how to prepare a driver update on a CD and DVD.

Prerequisites

• You received the driver update ISO image from your hardware vendor, or a trusted third-party vendor.
• You burned the driver update ISO image to a CD or DVD.

If only a single ISO image file ending in .iso is available on the CD or DVD, the burn process has not been successful. See your system’s burning software documentation for instructions on how to burn ISO images to a CD or DVD.

Procedure

1. Insert the driver update CD or DVD into your system’s CD/DVD drive, and browse it using the system’s file manager tool.
2. Verify that a single file rhdd3 is available. rhdd3 is a signature file that contains the driver description and a directory named rpms , which contains the RPM packages with the actual drivers for various architectures.

Performing an automatic driver update

This procedure describes how to perform an automatic driver update during installation.

Prerequisites

• You have placed the driver update image on a standard disk partition with an OEMDRV label or burnt the OEMDRV driver update image to a CD or DVD. Advanced storage, such as RAID or LVM volumes, may not be accessible during the driver update process.
• You have connected a block device with an OEMDRV volume label to your system, or inserted the prepared CD or DVD into your system’s CD/DVD drive before starting the installation process.

Procedure

1. Once you have completed the prerequisite steps, the drivers are automatically loaded when the installation program starts, and installed on the system during the installation process.

Performing an assisted driver update

This procedure describes how to perform an assisted driver update during installation.

Prerequisite

You have connected a block device without an OEMDRV volume label to your system and copied the driver disk image to this device, or you have prepared a driver update CD or DVD and inserted it into your system’s CD/DVD drive before starting the installation process.

If you burned an ISO image file to a CD or DVD but it does not have the OEMDRV volume label, you can use the inst.dd option with no arguments. The installation program provides an option to scan and select drivers from the CD or DVD. In this scenario, the installation program does not prompt you to select a driver update ISO image. Another scenario is to use the CD or DVD with the inst.dd=location boot option; this allows the installation program to automatically scan the CD or DVD for driver updates. For more information, see

Procedure

1. From the boot menu window, press the Tab key on your keyboard to display the boot command line.
2. Append the inst.dd boot option to the command line and press Enter to execute the boot process.
3. From the menu, select a local disk partition or a CD or DVD device. The installation program scans for ISO files, or driver update RPM packages.
4. Optional: Select the driver update ISO file.

This step is not required if the selected device or partition contains driver update RPM packages rather than an ISO image file, for example, an optical drive containing a driver update CD or DVD.

1. Use the number keys on your keyboard to toggle the driver selection.
2. Press c to install the selected driver. The selected driver is loaded and the installation process starts.

Performing a manual driver update

This procedure describes how to perform a manual driver update during installation.

Prerequisite

Place the driver update ISO image file on a USB flash drive or a web server, and connect it to your computer.

Procedure

1. From the boot menu window, press the Tab key on your keyboard to display the boot command line.
2. Append the inst.dd=location boot option to the command line, where location is a path to the driver update. Typically, the image file is located on a web server, for example, http://server.example.com/dd.iso, or on a USB flash drive, for example, /dev/sdb1 . It is also possible to specify an RPM package containing the driver update, for example http://server.example.com/dd.rpm.
3. Press Enter to execute the boot process. The drivers available at the specified location are automatically loaded and the installation process starts.

Additional resources

• For more information about the inst.dd boot option, see the upstream inst.dd boot option content.
• For more information about all boot options, see the upstream Boot Options content.

Disabling a driver

This procedure describes how to disable a malfunctioning driver.

Prerequisites

Procedure

1. From the boot menu, press the Tab key on your keyboard to display the boot command line.
2. Append the modprobe.blacklist=driver_name boot option to the command line.
3. Replace driver_name with the name of the driver or drivers you want to disable, for example:

Drivers disabled using the modprobe.blacklist= boot option remain disabled on the installed system and appear in the /etc/modprobe.d/anaconda-blacklist.conf file.

All CentOS Documentation content available under CC-BY-SA 3.0.

This page was built using a modified version of the Antora default UI. The source code for this UI is licensed under the terms of the MPL-2.0 license.

Источник

How does linux driver update work?

As far as I know no update on a linux machine requires a restart. Windows however needs to restart several times for a update to complete which is understandable because the hardware might be in use at the moment and a restart ensures that no software uses the driver. But how can an OS (or linux as an example) handle such a situation where you want to update a driver but it is currently in use?

2 Answers 2

Updates on Linux require a restart if they affect the kernel. Drivers are part of the kernel. It’s sometimes possible to upgrade a driver on Linux without rebooting, but that doesn’t happen often: the peripheral controller by the driver can’t be in use during the update, and the new driver version has to be compatible with the running kernel.

Upgrading a driver to a running system where the peripheral controlled by the driver is in use requires that the old driver leaves the peripheral in a state that the new driver is able to start with. The old and new driver must manage the handover of connections from clients as well. This is doable but difficult; how difficult depends on what the driver is driving. For example, a filesystem update without unmounting the filesystem requires the handover of some very complex data structures but is easy to cope with on the hardware side (just flush the buffers before the update, and start over with an empty cache). Conversely, an input driver only has to transmit a list of open descriptors or the like on the client side, but the hardware side requires that the new driver know what state the peripheral is in and must be managed carefully not to lose events.

Updating a driver on a live system is a common practice during development on operating systems where drivers can be dynamically loaded and unloaded, but usually not while the peripheral is in use. Updating a driver in production is not commonly done on OSes like Linux and Windows; I suppose it does get done on high-availability systems that I’m not familiar with.

Some drivers are not in the kernel (for example FUSE filesystems). This makes it easy to update them without updating the rest of the system, but it still requires that the driver not be in use (e.g. instances of the FUSE filesystem have to be unmounted and mounted again to make use of the new driver version).

Linux does have mechanisms to upgrade the kernel without restarting: Ksplice, Kpatch, KGraft. This is technically difficult as the updated version has to be compatible with the old version to a large extent; in particular, its data structures have to have exactly the same binary layout. A few distributions offer this service for security updates. These features are not (yet?) available in the mainline Linux kernel. On a mainline Linux kernel, a driver can be updated only if it’s loaded as a module and if the module can be unloaded and the new module is compatible with the running kernel.

Источник