sys: Remove $FreeBSD$: one-line .c pattern

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

sys/kbio.h: make pre-unicode keymap support optional

FreeBSD-9 had introduced support for the full set of Unicode
characters to the parsing and processing of keymap character tables.

This support has been extended to cover the table for accented
characters that are reached via dead key combinations in FreeBSD-13.2.

New ioctls have been introduced to support both the pre-Unicode and
the Unicode formats and keyboard drivers have been extended to support
those ioctls.

This commit makes the ABI compatibility functions in the kernel
optional and dependent on COMPAT_FREEBSD13 in -CURRENT.

The kbdcontrol command in -CURRENT and 13-STABLE (before 13.2) has
been made ABI compatible with old kernels to allow a new world to be
run on an old kernel (that does not have full Unicode support for
keymaps).

This commit is not to merged back to 12-STABLE or 13-STABLE. It is
part of review D38465, which has been split into 3 separate commits
due to different MFC and life-time requirements of either commit.

Approved by: imp
Differential Revision: https://reviews.freebsd.org/D38465

Support Unicode characters in keymap dead key tables

Support for Unicode characters had been added to the keyboard code,
but there are keymaps that have accented characters accessed via dead
key combinations, and those were still restricted to 8 bit codes.

This update to kbd.c adds support for Unicode characters and
compatibility code that allows a kbdcontrol command built from kbio.h
without these patches to work on a new kernel.

Compatibility code that allows a new kbdcontrol binary running on an
old kernel to load and display the dead key map will be committed in a
separate commit.

Reviewed by: imp, brooks
Approved by: brooks
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D38381

evdev: Extend EVIOCGRAB ioctl scope to cover kbd interface

of various keyboard drivers.
EVIOCGRAB ioctl execution on /dev/input/event# device node gains
exclusive access to this device to caller. It is used mostly for
development purposes and remote control software. See e.g.
https://reviews.freebsd.org/D30020 which is the reason of creation
of this change.
Keyboard grabbing is disabled in KDB and during panics.

MFC with: 4a0db5e2920c
Tested by: corvink
Differential revision: https://reviews.freebsd.org/D30542

hv_kbd: Fix build with EVDEV_SUPPORT kernel option disabled.

Reported by: olivier
MFC with: e4643aa4c4ff

hv_kbd: Add support for K_XLATE and K_CODE modes for gen 2 VMs

That fixes disabled keyboard input after Xorg server has been stopped.

Reviewed by: whu
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D28171

hv_kbd: Add evdev protocol support for gen 2 VMs

Reviewed by: whu
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D28170

Revert r355806: kbd drivers: don't double register keyboard drivers

r356087 made it rather innocuous to double-register built-in keyboard
drivers; we now set a flag to indicate that it's been registered and only
act once on a registration anyways. There is no misleading here, as the
follow-up kbd_delete_driver will actually remove the driver as needed now
that the linker set isn't also consulted after kbdinit.

kbd drivers: don't double register keyboard drivers

Keyboard drivers are generally registered via linker set. In these cases,
they're also available as kmods which use KPI for registering/unregistering
keyboard drivers outside of the linker set.

For built-in modules, we still fire off MOD_LOAD and maybe even MOD_UNLOAD
if an error occurs, leading to registration via linker set and at MOD_LOAD
time.

This is a minor optimization at best, but it keeps the internal kbd driver
tidy as a future change will merge the linker set driver list into its
internal keyboard_drivers list via SYSINIT and simplify driver lookup by
removing the need to consult the linker set.

kbd: provide default implementations of get_fkeystr/diag

Most keyboard drivers are using the genkbd implementations as it is;
formally use them for any that aren't set and make
genkbd_get_fkeystr/genkbd_diag private.

keyboard switch definitions: standardize on c99 initializers

A future change will provide default implementations for some of these where
it makes sense and most of them are already using the genkbd
implementation (e.g. get_fkeystr, diag).

kbd drivers: use kbdd_* indirection for diag invocation

These invocations were directly calling enkbd_diag(), rather than
indirection back through kbdd_diag/kbdsw. While they're functionally
equivent, invoking kbdd_diag where feasible (i.e. not in a diag
implementation) makes it easier to visually identify locking needs in these
other drivers.

hyperv/kbd: Channel read expects non-NULL channel argument.

MFC after: now
Sponsored by: Microsoft

hyperv/kbd: Add support for synthetic keyboard.

Synthetic keyboard is the only supported keyboard on GEN2 Hyper-V.

Submitted by: Hongjiang Zhang <honzhan microsoft com>
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D10196