- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r257669, r257672, r257673, r257676, r257678:

Call initarm_lastaddr() later in the init sequence, after establishing
static device mappings, rather than as the first of the initializations
that a platform can hook into. This allows a platform to allocate KVA
from the top of the address space downwards for things like static device
mapping, and return the final "last usable address" result after that and
other early init work is done.

Because some platforms were doing work in initarm_lastaddr() that needs to
be done early, add a new initarm_early_init() routine and move the early
init code to that routine on those platforms.

Make PTE_DEVICE a synonym for PTE_NOCACHE on armv4, to make it easier to
share the same code on both architectures.

Add new helper routines for arm static device mapping. The new code
allocates kva space from the top down for the device mappings and builds
entries in an internal table which is automatically used later by
arm_devmap_bootstrap(). The platform code just calls the new
arm_devmap_add_entry() function as many times as it needs to (up to 32
entries allowed; most platforms use 2 or 3 at most).

Remove imx local devmap code and use the essentially identical common
code that got moved from imx_machdep.c to arm/devmap.c.

MFC r257648, r257649, r257660:

Begin reducing code duplication in arm pmap.c and pmap-v6.c by factoring
out common code related to mapping device memory into a new devmap.c file.

Remove the growing duplication of code that used pmap_devmap_find_pa() and
then did some math with the returned results to generate a virtual address,
and likewise in reverse to get a physical address. Now there are a pair
of functions, arm_devmap_vtop() and arm_devmap_ptov(), to do that. The
bus_space_map() implementations are rewritten in terms of these.

Move remaining code and data related to static device mapping into the
new devmap.[ch] files. Emphasize the MD nature of these things by using
the prefix arm_devmap_ on the function and type names (already a few of
these things found their way into MI code, hopefully it will be harder to
do by accident in the future).

MFC r257595: Comments and style(9) only, no functional changes.

MFC r257199, r257200, r257217:

Remove all #include <machine/pmap.h> from arm code. It's already
included by vm/pmap.h, which is a prerequisite for arm/machine/pmap.h
so there's no reason to ever include it directly.

Remove #include <machine/frame.h> from all the arm code that doesn't
really need it. That would be almost everywhere it was included. Add
it in a couple files that really do need it and were previously getting
it by accident via another header.

Remove the last dregs of trapframe_t. It turns out only arm was using
this type, so remove it to make arm code more consistant with other
platforms.

MFC r257197:

Maximize available kva space by doing static device mapping from the top
of the address space downwards, and then returning the lowest mapped
device address from initarm_lastaddr(). Premap most of the device's
on-chip peripherals.

Maximize available kva space by doing static device mapping from the top
of the address space downwards, and then returning the lowest mapped
device address from initarm_lastaddr(). This adds over 500MB of kva
space compared to the old way of hardcoding the end address as 0xE0000000.

Also, pre-map most of the SoC's common memory-mapped devices using 1MB
section mappings so that all device access uses just a few TLB entries.
Graphics devices aren't mapped this way yet, but probably should be.

To provide this new functionality without pasting identical code into
multiple imxNN_machdep.c files, rework the imx machdep code so that
things common to the whole family of SoCs are in a new imx_machdep.c file.
The rewritten imxNN_machdep.c files contain just things specific to an
individual SoC.