Official installation images do not include non-free firmware. The most common method to load such firmware is from some removable medium such as a USB stick. Alternatively, unofficial installation images containing non-free firmware can be found at https://cdimage.debian.org/cdimage/unofficial/non-free/cd-including-firmware/. To prepare a USB stick (or other medium like a hard drive partition), the firmware files or packages must be placed in either the root directory or a directory named /firmware of the file system on the medium. The recommended file system to use is FAT as that is most certain to be supported during the early stages of the installation.

Tarballs and zip files containing current packages for the most common firmware are available from:

Just download the tarball or zip file for the correct release and unpack it to the file system on the medium.

If the firmware you need is not included in the tarball, you can also download specific firmware packages from the (non-free section of the) archive. The following overview should list most available firmware packages but is not guaranteed to be complete and may also contain non-firmware packages:

It is also possible to copy individual firmware files to the medium. Loose firmware could be obtained for example from an already installed system or from a hardware vendor.

Any firmware loaded during the installation will be copied automatically to the installed system. In most cases this will ensure that the device that requires the firmware will also work correctly after the system is rebooted into the installed system. However, if the installed system runs a different kernel version from the installer there is a slight chance that the firmware cannot be loaded due to version skew.

If the firmware was loaded from a firmware package, debian-installer will also install this package for the installed system and will automatically add the non-free section of the package archive in APT's sources.list. This has the advantage that the firmware should be updated automatically if a new version becomes available.

If loading the firmware was skipped during the installation, the relevant device will probably not work with the installed system until the firmware (package) is installed manually.

	Note
	If the firmware was loaded from loose firmware files, the firmware copied to the installed system will not be automatically updated unless the corresponding firmware package (if available) is installed after the installation is completed.

Depending on how the installation was performed, it might be that the need for some firmware was not detected during installation, that the relevant firmware was not available, or that one chose not to install some firmware at that time. In some cases, a successful installation can still end up in a black screen or a garbled display when rebooting into the installed system. When that happens, the following workarounds can be tried:

Once logged in into the installed system, it is possible to automate the detection of missing firmware, and to perform the required steps to enable them following this procedure:

Usually, rebooting is the simplest way to make sure all kernel modules are properly initialized; that's particularly important when one has booted the system with the nomodeset option as an interim measure.

	Note
	Installing firmware packages is very likely to require enabling the non-free section of the package archive. As of Debian GNU/Linux 11.0, running the isenkram-autoinstall-firmware command will do that automatically by creating a dedicated file (/etc/apt/sources.list.d/isenkram-autoinstall-firmware.list), pointing at a generic mirror.