Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

base: Remove support for the VTOC8 partitioning scheme

The removal of the sparc64 support in February 2020 obsoleted the
VTOC8 partitioning scheme as no other FreeBSD platform makes use
of it. Moreover, the code is bitrotting as nothing defines e. g.
LOADER_VTOC8_SUPPORT any more and, thus, should go now, too. With
this change, the following commits are reverted as far as VTOC8
is concerned and parts haven't already previously been deleted
along with prior sparc64 removals:
094fcb157d4c98211899cf09d06e2cf19149b7e0
a7d366e9589c95feda6f3bc78c59c6355d51f126
ba8d50d08b9df4e8213f9a6997ff6792ecebcd9b

The alignment example d9711c28efc4ec89ba5ea11f8fd63e9d0a7fc81b
added to the VTOC8 section of gpart.8 is folded into the MBR one.

This should finally conclude the deorbit of sparc64-specific bits.

We had joy, we had fun
we ran Unix on a Sun.
But that source and the song
of FreeBSD have all gone.

Credits to Michael Bueker for the original "Unix on a Sun" and Rod
McKuen for the "Seasons in the Sun" lyrics.

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

GEOM: Introduce partial confxml API

Traditionally the GEOM's primary channel of information from kernel to
user-space was confxml, fetched by libgeom through kern.geom.confxml
sysctl. It is convenient and informative, representing full state of
GEOM in a single XML document. But problems start to arise on systems
with hundreds of disks, where the full confxml size reaches many
megabytes, taking significant time to first write it and then parse.

This patch introduces alternative solution, allowing to fetch much
smaller XML document, subset of the full confxml, limited to 64KB and
representing only one specified geom and optionally its parents. It
uses existing GEOM control interface, extended with new "getxml" verb.
In case of any error, such as the buffer overflow, it just transparently
falls back to traditional full confxml. This patch uses the new API in
user-space GEOM tools where it is possible.

Reviewed by: imp
MFC after: 2 month
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D34529

gpart: Avoid geom_gettree() call in "bootcode -b".

geom_gettree() may be pretty expensive on large systems, and it is
not needed if only -b flag specified, that is processed by kernel.

MFC after: 1 month

GEOM: Introduce gctl_add_param() API.

Make gctl_add_param() API public, allowing more precise control over
parameter flags. Previously it was impossible to properly declare
write-only ASCII parameters, used for result reporting, they were
declared as read-write binary instead, that was not nice.

MFC after: 1 month

Add a “skip_dsn” option to g_part's bootcode verb to prevent g_part_mbr
from setting the volume serial number. This unbreaks older boot blocks
that don't support serial numbers, and allows boot0cfg to set the serial
number itself if requested by the user.

Submitted by: lev@, yuripv@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D17386

Normalize the g(eom,cache,part,...) build.

Rather then combining hardlink creation for the geom(8) binary with
shared library build, move libraries to src/lib/geom so they are
built and installed normally. Create a common Makefile.classes
which is included by both lib/geom/Makefile and sbin/geom/Makefile
so the symlink and libraries stay in sync.

The relocation of libraries allows libraries to be build for 32-bit
compat. This also reduces the number of non-standard builds in
the system.

This commit is not sufficent to run a 32-bit /sbin/geom on a 64-bit
system out of the box as it will look in the wrong place for libraries
unless GEOM_LIBRARY_PATH is set appropriatly in the environment.

Reviewed by: bdrewery
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15360