Hi all,

          I didn't get any comment on this patch, so I try to re-submit.

My ARM board hanged at the initial "Calibrating delay loop" message.

After some inspection, I found out the problem to be with commit
adf8b37bafc1495393201a2ae4235846371870d0. This commit introduces stack
unwinding for ARM, and set it enabled by default. However, it seems to
not work with buggy or not-EABI compilers.

My suggestion is to keep the feature (which is fine) but change the
default setting of the option (see the attached patch).

Having this option enabled by default, in fact, means that the kernel
does not boot if the user has a wrong compiler. If so, inspecting the
reason of the hang may require too much time (especially for people not
familiar with this option).

Consider that people may not know that their problem is related to the
ARM_UNWIND option. Therefore, they may waste time bisecting just to
understand where their problem really is.

If we disable this option by default, users who know the real meaning of
the option will still be able of setting it to the proper value.

Any comment ?

Many thanks,

                   Claudio