Approved by:	re (hrs, kensmith)

Integrate kbdmux(4) into syscons(4) and kbd code.

By default syscons(4) will look for the kbdmux(4) keyboard first, and then,
if not found, look for any keyboard.

Current kbd code is modified so if kbdmux(4) is the current keyboard, all
new keyboards are automatically added to the kbdmux(4).

Switch to kbdmux(4) can be done at boot time, by loading kbdmux module at
the loader prompt, or at runtime, by kldload'ing the kbdmux module and
releasing current active keyboard.

If, for whatever reason, kbdmux(4) is not required/desired then just do
not load it and everything should work as before. It is also possible to
kldunload kbdmux at runtime and syscons(4) will automatically switch to
the first available keyboard.

Approved by:	re (scottl)

When SC_DISABLE_KDBKEY or SC_DISABLE_REBOOT are not defined allow the
same behavior to be controlled by the sysctls, hw.syscons.kbd_kbdkey
and hw.syscons.kbd_reboot respectively.

PR:		kern/72728
Submitted by:	Luca Morettoni <morettoni at libero dot it>
Approved by:	re (scottl)

	ofw_syscons.c 1.9, s3_pci.c 1.10, scgfbrndr.c 1.23, scmouse.c 1.40,
	scvgarndr.c 1.20, scvidctl.c 1.37, syscons.c 1.439, syscons.h 1.85,
	tga.c 1.8, vesa.c 1.52, vga.c 1.35

Add a font width argument to vi_load_font_t, vi_save_font_t and vi_putm_t
and do some preparations for handling 12x22 fonts (currently lots of code
implies and/or hardcodes a font width of 8 pixels). This will be required
on sparc64 which uses a default font size of 12x22 in order to add font
loading and saving support as well as to use a syscons(4)-supplied mouse
pointer image.

Approved by:	re (scottl)

  scmouse.c, 1.39:  In set_mouse_pos(), try to avoid division by zero errors.

  scvidctl.c, 1.36:
	In sc_set_text_mode(), reset fontwidth if it is <= 0.
	Eliminates division by zero errors in syscons driver.

Approved by:	re (scottl)

  Prevent division by zero errors in sc_mouse_move()
  by explicitly setting sc->font_width, in the same
  places where sc->font_size is set, instead of
  relying on the default initialized value of 0 for sc->font_width.

PR:             kern/84836
Reported by:    Andrey V. Elsukov <bu7cher at yandex dot ru>
Approved by:	re (scottl)

kbdmux(4) keyboard multiplexer integration

o Add two new ioctl's KBADDKBD and KBRELKBD. These are used to add and remove
  keyboard to (and from) kbdmux(4) keyboard multiplexer;

o Introduce new kbd_find_keyboard2() function. It does exactly the same job
  as kbd_find_keyboard() function except it allows to specify starting index.
  This function can be used to iterate over keyboards array;

o Re-implement kbd_find_keyboard() as call to kbd_find_keyboard2() with starting
  index of zero;

o Make sure syscons(4) passed KBADDKBD and KBRELKBD ioctl's onto currently
  active keyboard.

These changes should not have any visible effect.

Approved by:	re (kensmith)

function pointer to the vga render dispatch table and initialized it with
vga_nop.  The problem is that vga_nop() is a varargs function, and the
table declares a non-varargs function pointer.  On amd64 (and I think ppc),
mixing varargs and non-varargs function pointers is fatal.

Change vga_nop() and gfb_nop() from varargs to non-varargs do-nothing
functions.  This stops the stack corruption that only happened on amd64.

Approved by:  re (scottl)

solution against the ioctl collisions.

Submitted by:	Antoine Brodin <antoine.brodin at laposte net>
PR:		kern/81867