what would take to allow binary upgrade to amd64?

[Dylan Cochran]

On Sun, May 30, 2010 at 4:30 PM, Eitan Adler <lists at eitanadler.com> wrote:
> On Sun, May 30, 2010 at 10:52 PM, Rob Farmer <rfarmer at predatorlabs.net> wrote:
>> On Sun, May 30, 2010 at 11:51 AM, Eitan Adler <lists at eitanadler.com> wrote:
>>> I know that attempting to change from i386 to amd64 is is not possible
>>
>> The proper procedure for such an upgrade is as follows:
> ....
>>
>> If the thought of reformatting your system is scary, because you don't
>> have backups or aren't sure they are comprehensive or work, then solve
>> that problem, rather than trying to invent workarounds to cover for
>> bad system administration. It will serve you much better in the long
>> run.
> This isn't my question. I know how to currently perform the upgrade.
>
> My question is
> a) is it possible in theory to allow binary upgrades to be done?
> and b) if yes how much work would it take?

In theory, yes, it is possible; in practice, in limited scope, it is
practical to do so. I have done it, and have the ability to do so at
will.

As for widespread use, the COMPAT_FREEBSD32 option needs to be fixed
first, because as it stands now a 64bit kernel with a 32bit userland
is not complete, for example, on 8.0, a 32bit ifconfig cannot set an
ip address on an interface, because of ioctl incompatibility. This
prevents the intermediate step of running a 32bit userland with a
64bit kernel (though it can be sidestepped by segregating the
architecture specific parts of the userland).

Full 32bit support on 64bit kernels has other, more widespread
benefits then an after install sidegrade. Work is already moving in
this direction, as it's a natural progression for architecture
support.