Debian GNU/Linux 8 supports ten major architectures and several variations of each architecture known as “flavors”.

This document covers installation for the 32-bit hard-float ARMv7 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 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 systems are known to work with Debian/armhf using the multiplatform (armmp) kernel:

Generally, the ARM multiplatform support in the Linux kernel allows running debian-installer on armhf systems not explicitly listed above, as long as the kernel used by debian-installer has support for the target system's components and a device-tree file for the target is available. In these cases, the installer can usually provide a working installation, but it may not be able to automatically make the system bootable. Doing that in many cases requires device-specific information.

When using debian-installer on such systems, you may have to manually make the system bootable at the end of the installation, e.g. by running the required commands in a shell started from within debian-installer.

Multiprocessor support — also called “symmetric multiprocessing” or SMP — is available for this architecture. The standard Debian 8 kernel image has been compiled with SMP-alternatives support. This means that the kernel will detect the number of processors (or processor cores) and will automatically deactivate SMP on uniprocessor systems.

Having multiple processors in a computer was originally only an issue for high-end server systems but has become common in recent years nearly everywhere with the introduction of so called “multi-core” processors. These contain two or more processor units, called “cores”, in one physical chip.

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” images (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 jessie 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 http://xorg.freedesktop.org/. Debian 8 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 hard-float ARMv7, 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.