Debian GNU/Linux 12 supports 9 major architectures and several variations of each architecture known as “flavors”.

This document covers installation for the 32-bit soft-float ARM architecture using the Linux kernel. If you are looking for information on any of the other Debian-supported architectures take a look at the Debian-Ports pages.

The ARM architecture has evolved over time and modern ARM processors provide features which are not available in older models. Debian therefore provides three ARM ports to give the best support for a very wide range of different machines:

Technically, all currently available ARM CPUs can be run in either endian mode (big or little), but in practice the vast majority use little-endian mode. All of Debian/arm64, Debian/armhf and Debian/armel support only little-endian systems.

ARM systems are much more heterogeneous than those based on the i386/amd64-based PC architecture, so the support situation can be much more complicated.

The ARM architecture is used mainly in so-called “system-on-chip” (SoC) designs. These SoCs are designed by many different companies with vastly varying hardware components even for the very basic functionality required to bring the system up. System firmware interfaces have been increasingly standardised over time, but especially on older hardware firmware/boot interfaces vary a great deal, so on these systems the Linux kernel has to take care of many system-specific low-level issues which would be handled by the mainboard's BIOS/UEFI in the PC world.

At the beginning of the ARM support in the Linux kernel, the hardware variety resulted in the requirement of having a separate kernel for each ARM system in contrast to the “one-fits-all” kernel for PC systems. As this approach does not scale to a large number of different systems, work was done to allow booting with a single ARM kernel that can run on different ARM systems. Support for newer ARM systems is now implemented in a way that allows the use of such a multiplatform kernel, but for several older systems a separate specific kernel is still required. Because of this, the standard Debian distribution only supports installation on a selected number of such older ARM systems, alongside the newer systems which are supported by the ARM multiplatform kernels (called “armmp”) in Debian/armhf.

The following platforms are supported by Debian/armel; they require platform-specific kernels.

You may be able to keep above listed devices running for some time, see the Release Notes for Debian 11.

Debian's support for graphical interfaces is determined by the underlying support found in X.Org's X11 system, and the kernel. Basic framebuffer graphics is provided by the kernel, whilst desktop environments use X11. Whether advanced graphics card features such as 3D-hardware acceleration or hardware-accelerated video are available, depends on the actual graphics hardware used in the system and in some cases on the installation of additional “firmware” blobs (see Section 2.2, “Devices Requiring Firmware”).

Nearly all ARM machines have the graphics hardware built-in, rather than being on a plug-in card. Some machines do have expansion slots which will take graphics cards, but that is a rarity. Hardware designed to be headless with no graphics at all is quite common. Whilst basic framebuffer video provided by the kernel should work on all devices that have graphics, fast 3D graphics invariably needs binary drivers to work. The situation is changing quickly but at the time of the bookworm release free drivers for nouveau (Nvidia Tegra K1 SoC) and freedreno (Qualcomm Snapdragon SoCs) are available in the release. Other hardware needs non-free drivers from 3rd parties.

Details on supported graphics hardware and pointing devices can be found at https://wiki.freedesktop.org/xorg/. Debian 12 ships with X.Org version 7.7.

Almost any network interface card (NIC) supported by the Linux kernel should also be supported by the installation system; drivers should normally be loaded automatically.

On 32-bit soft-float ARM, most built-in Ethernet devices are supported and modules for additional PCI and USB devices are provided.

Linux supports a large variety of hardware devices such as mice, printers, scanners, PCMCIA/CardBus/ExpressCard and USB devices. However, most of these devices are not required while installing the system.