Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Disconnect sun4v architecture from the three.

Some files keep the SUN4V tags as a code reference, for the future,
if any rewamped sun4v support wants to be added again.

Reviewed by: marius
Tested by: sbruno
Approved by: re

Bypass isa_probe_children(9) and directly call bus_generic_attach(9)
in order to avoid the invasive probes done by identify-routines of
ISA drivers, which may access unassigned addresses or those of
unrelated devices and thus in turn can trigger master/target aborts
as revealed by r182108 and ahc(4). I think that this is also the
cause of the hang previously seen on B100 blades during boot.
Bypassing isa_probe_children(9) also avoids adding ISA hints, which
just can be wrong for sparc64.

Reported by: gavin

- Remove redundant inclusion of opt_global.h.
- Use __FBSDID in autoconf.c.

MFC after: 3 days

remove 13 (largely) redundant files and switch to the sparc64/sparc64 version

Reviewed by: jb (mentor rwatson)

Create nexus in configure_first() instead of in configure(). This
makes sure that sysinit tasks that run after configure_first(),
but before configure() have a nexus to hang devices off.

Call cninit_finish() from configure_final().

Split configure() into 3 separate steps like we do on other
architectures. This makes it possible to insert hooks before and
after the device attachment step.

Run configure at SI_SUB_THIRD instead of SI_SUB_ANY like other
architectures.

Remove unneeded opt headers.

Noticed by: benno

Moved nfs_diskless setup code from autoconf.c to nfsclient/nfs_diskless.c
so that it is MI. Allow nfs_mountroot to return an error if the nfs_diskless
struct is not valid, rather than panicing later on. Call nfs_setup_diskless()
from nfs_mountroot if NFS_ROOT is defined, like bootpc_init(). Removed legacy
root mount support for sparc64, and enabled NFS_ROOT by default.

Centralize the "bootdev" and "dumpdev" variables. They are still pretty
bogus all things considered, but at least now they don't camouflage as
being MD variables.

Add partial support for NFS_ROOT for sparc64 (only supported in in
connection with BOOTP_NFSROOT right now).

Add a nexus device for sparc64, which uses the OpenFirmware to attach UPA
devices (mostly host bridges) and handles interrupt allocation and setup.

Remove call to cninit_finish().

The author isn't a [UC] Regents. Correct the copyright language.

Flesh out the sparc64 port considerably. This contains:
- mostly complete kernel pmap support, and tested but currently turned
off userland pmap support
- low level assembly language trap, context switching and support code
- fully implemented atomic.h and supporting cpufunc.h
- some support for kernel debugging with ddb
- various header tweaks and filling out of machine dependent structures

Add skeleton machine dependent headers and c files for a port of freebsd
to a new architecture. This is the base of the sparc64 port, but contains
limited machine dependent code, and can be used a base for ports. Included
are:
- standard machine dependent headers, tweaked for a 64 bit, big endian
architecture, including empty versions of all the machine dependent
structures
- a machine independent atomic.h, which can be used until a port has
support for interrupts and the operations really need to be atomic
- stub versions of all the machine dependent functions, which panic
when called and print out the name of the function that needs to
be implemented. functions which are normally in assembly files are
not included, but this should reduce the number of different undefined
references on the first few compiles from hundreds to 5 or 6
Given minimal startup code and console support it should be trivial to
make this compile and run the first few sysinits on almost any architecture.

Requested by: alfred, imp, jhb