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Announcing the NetBSD Port Tier System

        Dear Users of NetBSD,

When the NetBSD project was conceived almost two decades ago, the
hardware scene was different than today.  There was a multitude of
hardware available for running Unix-like operating systems, and as
a key point all hardware had roughly equal capabilities.  The only
sensible choice at that time was to embrace portability.  NetBSD
got portability correct from the start, and other projects followed
in NetBSD's footsteps only years later.

Fast-forwarding to the present day, portability is still of paramount
importance to an operating system.  However, the thing that has
changed is that hardware no longer has roughly equal capabilities:
new hardware with new capabilities and requirements is constantly
being developed, while old hardware remains the same.

Historically, in NetBSD it has been seen that it is the responsibility
of a developer implementing new features to make sure all ports
are up-to-date and working after the change.  This responsibility
constitutes a sizable effort in cases like rearchitecting the kernel
to support modern locking and multiprocessor features, or during
a new toolchain import.

Effective immediately, the project is instating a three-level port
tier system which separates industrially relevant high-activity
ports for modern hardware from the rest.  Focus ports receive
official development priority while the maintenance of other
platforms is made the responsibility of the people using them.
This will allow NetBSD to more efficiently stay on the cutting edge
of the server, embedded and desktop systems of today and tomorrow.

In no way does this mean that NetBSD is abandoning support for old
hardware.  Support for ports such as vax, mac68k and pmax is still
more than welcome.  However, users of such ports are asked to take
a more active role in development, maintenance and feedback for
the platforms they know and love.

A port's tier is decided by the core team based on input from users
and developers.  The tier may change both up and down due to the
activity level of user/developer community and the current relevance
of the hardware supported by the port.  The official up-to-date
list is always available at:

For reading convenience, the current port tier ranking along with
the implications of the tiers is also presented below.

        Tier I: Focus -- support is part of NetBSD's strategy

* modern server, embedded and desktop hardware
* machine independent (MI) changes should benefit these ports
* MI changes must be tested on at least one of these ports
* it is the developer's responsibility to implement machine
  dependent (MD) support necessary for changes, fix build problems
  and aid in debugging with any platform-specific problems
* even within a port, common sense should be used
  (cf. the i386 port which still supports 486)
* regressions in the automated NetBSD test suite (/usr/tests)
  are not allowed

amd64 evbarm evbmips evbppc hpcarm i386 sparc64 xen

CPUs: arm i386 mips powerpc sparc64 x86_64

        Tier II: Organic -- evolving at its own pace

* dated hardware or low community activity
* generally speaking, the port boots and works, but keeping it working
  is the responsibility of the user community
  + this includes, but is not limited to, kernel changes and
    toolchain upgrades
* developers committing MI changes are still encouraged to keep
  ports up-to-date when it can be easily done
* MI architecture decisions may penalize organic ports if
  there is a benefit for focus ports
* if the port is not working at release time, a release is
  done without the port and the port is moved down to the
  life support tier

acorn26 acorn32 algor alpha amiga amigappc arc atari bebox
cats cesfic cobalt dreamcast emips evbsh3 ews4800mips hp300
hp700 hpcmips hpcsh ia64 ibmnws iyonix landisk luna68k mac68k
macppc mipsco mmeye mvme68k mvmeppc netwinder news68k
newsmips next68k ofppc pmax prep rs6000 sandpoint sbmips
sgimips sh3 shark sparc sun2 sun3 sun68k vax x68k zaurus

CPUs: alpha arm hppa m68010 m68k mips powerpc sh3 sparc vax

        Tier III: Life support -- severely incapacitated or broken

* organic ports get moved here if they do not complete a build
  for 6 months or are otherwise suspected to be broken
* it is the responsibility of the users of a organic port to show
  it is working, not the other way around
* movement to life support causes a mail to be sent out to the port
  mailing list and the portmaster
* port will be bumped up to organic when it is shown to be working
* if the port is not reported fixed within the next 6-12 months,
  it will be moved to the Attic

currently none

  - The Core Team

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