Support for 64bit userspace.

[M. Warner Losh]

In message: <AANLkTikZKS8iuST1dp5yfo6P6kaif4b1YzsKAskk_wB=@mail.gmail.com>
            Juli Mallett <jmallett at freebsd.org> writes:
: Hi JC,
: 
: On Wed, Jul 28, 2010 at 16:32, Jayachandran C. <c.jayachandran at gmail.com> wrote:
: > On Wed, Jul 28, 2010 at 2:04 AM, Jayachandran C.
: > <c.jayachandran at gmail.com> wrote:
: >> Here's my initial work to get 64bit user space.  With this set of
: >> changes, I can boot to the single user shell with n64 /sbin/init and
: >> /bin/sh.  There are still issues to fix, and the dynamic loader is
: >> still not working, but I think this would be a good time to get some
: >> initial feedback.
: >
: > The dynamic loader seems to work after some straight-forward changes.
: > The only change is that the got[1] entry needs to be 64-bit.  The
: > changes are attached.
: >
: > There is still an occasional kernel panic in n64, which I need to
: > track down - but I think the changes other than pmap.c/pmap64.c are
: > ready for check in.  I would like some feedback on pmap64.c I can
: > clean it up for check in.
: 
: I'm uncomfortable with pmap.c and pmap64.c.  I don't get the
: impression that the ifdefs required to do both in the same file are
: really a great burden, but obviously my efforts are incomplete
: compared to yours.  It seems like there are very few operations that
: should care about how deep the page tables are and that macros and
: ifdefed inline functions are the way to go.  If you check it in as two
: files, I'll probably just go through and ifdef the deltas that can't
: be eliminated.  What do you think are the problem areas that justify
: having two different files?

Eventually, and by no means should this hold things up today, I'd like
to be able to run 32-bit and 64-bit programs on the same system...

Warner