Possible values for `uname -m`

Question

The uname(1) command-line utility has a -m option which prints the "machine hardware name".

On Linux, this field comes from the machine member of struct utsname, as populated by the uname(2) system call.

Many other language APIs return this information:

• Python: os.uname() and platform.machine()
• PHP: php_uname()

What are the possible values for the "machine" field?

Answer 1

Linux

(v4.12 - 2017-July)

Let's refer to the source of the newuname system call.

Tracking this down is complicated by the fact that Linux has UTS namespaces, but the init_uts_ns machine field is initialized by the UTS_MACHINE macro, which is defined per-architecture.

Further complicating matters, machine can be overridden via override_architecture(), if the process is running under a 32-bit "compat" personality, to COMPAT_UTS_MACHINE.

UTS_MACHINE defaults in Makefile to the same thing as ARCH. However, many platforms have separate sub-architectures under the same arch directory, so they set UTS_MACHINE themselves

With the list of directories in arch/ and a little grep-ing of the Linux kernel sources (git grep 'UTS_MACHINE\s*:=' and git grep COMPAT_UTS_MACHINE), we can arrive at this list:

• alpha

• arc

• arm

• aarch64_be (arm64)
• aarch64 (arm64)
• armv8b (arm64 compat)

• armv8l (arm64 compat)

• blackfin

• c6x
• cris
• frv
• h8300
• hexagon
• ia64
• m32r
• m68k
• metag
• microblaze
• mips (native or compat)
• mips64 (mips)
• mn10300
• nios2
• openrisc
• parisc (native or compat)
• parisc64 (parisc)
• ppc (powerpc native or compat)
• ppc64 (powerpc)
• ppcle (powerpc native or compat)
• ppc64le (powerpc)
• s390 (s390x compat)
• s390x
• score
• sh
• sh64 (sh)
• sparc (native or compat)
• sparc64 (sparc)
• tile
• unicore32
• i386 (x86)
• i686 (x86 compat)
• x86_64 (x64)
• xtensa