Re: Devicetree spec: Specifying /cpus/cpu@* unit address format?

--F/G3fJTJhrM6n45B
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Fri, Apr 03, 2026 at 06:06:17PM +0800, Vivian Wang wrote:
> (Also posted at: https://github.com/devicetree-org/devicetree-specificati=
on/issues/86 )
>=20
> Hi all,
>=20
> Presently, there seems to be some confusion in the community about the
> format of unit addresses for "/cpus/cpu@*" nodes for a CPU with ID > 9, e=
=2Eg.
>=20
> =A0 =A0 cpu@??? {
> =A0 =A0 =A0 =A0 reg =3D <10>;
> =A0 =A0 =A0 =A0 /* reg =3D <0xa>; */ /* This should be equivalent */
> =A0 =A0 }
>=20
>=20
> Should this be a decimal "cpu@10", or hexadecimal "cpu@a"? I can't find
> any explicit specification.

It should be hex.  That's a general convention for unit addresses.
Before flattened trees, OF essentially never used decimal
representations of things.

--=20
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

--F/G3fJTJhrM6n45B
Content-Type: application/pgp-signature; name=signature.asc

-----BEGIN PGP SIGNATURE-----
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=Fs1W
-----END PGP SIGNATURE-----

--F/G3fJTJhrM6n45B--