Note that subdirectories correspond to DEB_HOST_ARCH_CPU. Therefore, amd64 is
used for kfreebsd-amd64, i386 for kfreebsd-i386 and hurd-i386, and arm for
armel and armhf.

Here is how some information on where and how the various archdefs were
generated (other details are in README.source):

- amd64: ATLAS 3.10.1 / karaba.cepremap.org / wheezy / 2013-06-04
- arm:
  + GENERIC32.tar.bz2 (for armel): ATLAS 3.10.1 / vamana.villemot.name (Raspberry Pi) / sid / 2013-07-01
  + GENERIC32FPV3D16MAC.tar.bz2 (for armhf): ATLAS 3.10.3 / asachi.debian.org / sid / 2017-08-10
- arm64: ATLAS 3.10.3 / asachi.debian.org / sid / 2016-08-05
- i386: from ATLAS 3.10.1 tarball
- ia64: ATLAS 3.10.1 / merulo.debian.org / sid / 2013-06-08
- m68k: created by John Paul Adrian Glaubitz (see https://bugs.debian.org/945913)
- mipsel: ATLAS 3.10.1 / eder.debian.org / sid / 2013-06-07
- mips64el: ATLAS 3.10.2 / etler.debian.org / sid / 2015-11-08
- powerpc: ATLAS 3.10.1 / partch.debian.org / sid / 2013-06-06
- ppc64: ATLAS 3.10.3 / pizzetti.debian.org / sid / 2017-08-10
- ppc64el: ATLAS 3.10.3 / plummer.debian.org / sid / 2016-08-05
- riscv64: created by Manuel A. Fernandez Montecelo (see https://bugs.debian.org/897128)
- s390x:
  + IBMz964.tar.bz2: ATLAS 3.10.1 / zelenka.debian.org / sid / 2013-06-06
  + IBMz1264.tar.bz2: created by Dimitri John Ledkov for Ubuntu
- sparc64: ATLAS 3.10.3 / notker.debian.net / sid / 2017-08-13
