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Re: ARMv4-support in armel/squeeze?

+++ Christoph Biedl [2010-12-19 19:55 +0100]:
> Hi,
> there's an ARMv4 based box running Debian lenny, I'd like to upgrade
> to squeeze. As the system doesn't boot a newly created armel file
> system ("Kernel panic - not syncing: Attempted to kill init!" after
> rootfs has been mounted) I was wondering whether this CPU
> is still supported.
> Now reading the wiki over and over again I become more and more
> confused:
> * According to <http://wiki.debian.org/ArmEabiPort>:
> | Arm will be dropped in etch+2, assuming that the above gcc changes
> | to support armv4 CPUs in armel prove practical. If we cannot support
> | armv4 in armel then arm will remain around until we drop
> | v4/StrongARM support, i.e. the port falls into general disuse.
> As arm has been dropped in squeeze => YES
> * According to <http://wiki.debian.org/ArmEabiProblems>:
> | nwutil: Hardware utilities for NetWinder hardware, based on the
> | StrongARM SA-110, which is armv4 and hence not supported in armel.
> => NO
> Which of these documents need an amendment? 

Niether is wrong, really. Arm has stayed around until we drop
strongarm/v4 support. That's now (well, very soon indeed). armel does
not support v4, only v4t, but arm is being dropped anyway (and armhf
is well on the way to being introduced). arm will stay around for
another 18 months or so as 'oldstable', and then v4 machines will be
pretty-much unsupported in Debian unless someone steps up to support

This is unfortunate for people still running v4 hardware (strongarm,
pretty much - do have something else which is v4?), but continuing to
support v4 hardware imposes significant overhead on people running
later hardware. There is plenty of pressure to move to v5-or-later
(i.e. drop v4t too). Ubuntu has already moved to v7 or later only.

Debian has always tried hard to support as much hardware as possible,
but it does (often, and in this case) affect newer hardware so at some
point one has to let hardware drop off the bottom. Does the
popularity-contest info record any CPU details? It would be helpful
for having some idea of the mix currently in use.

I believe that the v4-support in the toolchain was eventually done,
but I'm not sure if it's mainlined, and we definately haven't changed
the default Debian build. Can someone who knows/recalls the details
tell us what the cost of building armel for v4 would be, and if it is
actually possible currently? If anyone wants to see this hapen badly
enough they need to find the patches, check it works, and argue the
toss here about what Debian should do about supporting old hardware.

We will be disucssing which arm flavours Debian
builds/maintains/defaults-to at the Debain Arm/Embedded sprint in
February. The more info we have before then to make decisions, the

It's very difficult to support people with reliable old Netwinders at
one end, and others who want to use all the shiny stuff on their new
arm netbooks/tablets at the other witout building 6 different arm
distros. What an appropriate compromise is, is currently a hot topic.
I guess you just opened it up for more input. 

Principal hats:  Linaro, Emdebian, Wookware, Balloonboard, ARM

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