Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r316636,r316642,r316675,r316733,r316737,r316741,r316827,r316830,r316865,r316878:

Fix removal of the keyboard cursor image in text mode, especially
in the vga renderer. Removal used stale attributes and didn't try to
merge with the current attribute for cut marking, so special rendering
of cut marking was lost in many cases. The gfb renderer is too broken
to support special rendering of cut marking at all, so this change is
supposed to be just a style fix for it. Remove all traces of the
saveunder method which was used to implement this bug.

Fix drawing of the cursor image in text mode, only in the vga
renderer. This used a stale attribute from the frame buffer instead
of from the saveunder, but did merge with the current attribute for
cut marking so it caused less obvious bugs (subtle misrendering for
the character under the cursor).

The saveunder method may be good in simpler drivers, but in syscons
the 'under' is already saved in a better way in the vtb. Just redraw
it from there, with visible complications for cut marking and
invisible complications for mouse cursors. Almost all drawing
requests are passed a flag 'flip' which currently means to flip to
reverse video for characters in the cut marking region, but should
mean that the the characters are in the cut marking regions so should
be rendered specially, preferably using something better than reverse
video. The gfb renderer always ignores this flag. The vga renderer
ignored it for removal of the text cursor -- the saveunder gave the
stale rendering at the time the cursor was drawn. Mouse cursors need
even more complicated methods. They are handled by drawing them last
and removing them first. Removing them usually redraws many other
characters with the correct cut marking (but transiently loses the
keyboard cursor, which is redrawn soon). This tended to hide the
saveunder bug for forward motions of the keyboard cursor. But slow
backward motions of the keyboard cursor always lost the cut marking,
and fast backwards motions lost in for about 4 in every 5 characters,
depending on races with the scrn_update() timeout handler. This is
because the forward motions are usually into the region redrawn for
the mouse cursor, while backwards motions rarely are.

Text cursor drawing in the vga renderer used also used a
possibly-stale copy of the character and its attribute. The vga
render has the "optimization" of sometimes reading characters from the
screen instead of from the vtb (this was not so good even in 1990 when
main memory was only a few times faster than video RAM). Due to care
in update orders, the character is never stale, but its attribute
might be (just the cut marking part, again due to care in order).

gfb doesn't have the scp->scr pointer used for the "optimization", and
vga only uses this pointer for text mode. So most cases have to
refresh from the vtb, and we can be sure that the ordering of vtb
updates and drawing is as required for this to work.

------------------------------------------------------------------------
r316642 | bde | 2017-04-08 10:00:39 +0000 (Sat, 08 Apr 2017) | 36 lines

Quick fix for removal of the mouse cursor in vga direct graphics modes
(that is, in all supported 8, 15, 16 and 24-color modes). Moving the
mouse cursor while holding down a button (giving cut marking) left a
trail of garbage from misremoved mouse cursors (usually colored
rectangles and not cursor shapes). Cases with a button not held down
worked better and may even have worked.

No renderer support for removing (software) mouse cursors is needed
(and many renderers don't have any), since sc_remove_mouse_image()
marks for update the region containing the image and usually much
more. The mouse cursor can be (partially) over as many as 4 character
cells, and removing it in only the 1-4 cells occupied by it would be
best for efficiency and for avoiding flicker. However,
sc_remove_mouse_image() can only mark a single linear region and
usually marks a full row of cells and 1 more to be sure to cover the
4 cells. It always does this, so using the special rendering method
just wastes even more time and gives even more flicker. The special
methods will be removed soon.

The general method always works. vga_pxlmouse_direct() appeared to
defer to it by returning immediately if !on. However,
vga_pxlmouse_direct() actually did foot-shooting using a disguised
saveunder method. Normal order near a mouse move is:
(1) remove the mouse cursor in the renderer (optional)
(2) remove the mouse cursor again and refresh the screen over the
mouse cursor and much more from the vtb. When the mouse has
actually moved and a button is down, many attributes in this
region are changed to be up to date with the new cut marking
(3) draw the keyboard cursor again if it was clobbered by the update
(4) draw the mouse cursor image in its new position.
The bug was to remove the mouse cursor again in step (4), before the
drawing it again in (4), using a saveunder that was valid in step (1)
at best. The quick fix is to use the saveunder in step (1) and not
in step (4). Using it in step (4) also used it before it was
initialized, initially and after mode and screen switches.

------------------------------------------------------------------------
r316675 | bde | 2017-04-10 06:19:09 +0000 (Mon, 10 Apr 2017) | 29 lines

Special rendering methods for removing mouse cursors cannot be removed
like I hoped, since they are needed for removing parts over the border.
Continue fixing bugs in them.

In the vga planar mode renderer, remove removal of the part of the
image over the text window. This was hard-coded for nearly 8x16 fonts
and in practice didn't remove enough for 8x8 fonts. This used the
wrong attribute over cutmarked regions. The caller refreshes with the
correct attribute later, so the attribute bug only caused flicker.
The caller uses the same hard-coding, so the refreshes fix up all the
spots with the wrong attribute, but keep missing the missed spots.
This still gives trails of bits of cursors for cursor motions in the
affected configurations (mainly depth 4 modes with 8x8) fonts. 8x14
fonts barely escape the problem since although the cursor is drawn
as 16x16, its active part is only 9x13 and the active part fits in
the hard-coded 2x2 character cell window for 8x14 fonts. 8x8 fonts
need a 2x3 window.

In the fb non-sparc64 renderer, the buggy image removal was buggier
and was already avoided by returning before it. Remove it completely
and fix nearby style bugs. It was essentially the same as for the vga
planar mode renderer (obfuscated by swapping x and y). This was buggier
since fb should handle more types of hardware so the hard-coding is
wronger.

The remaining fb image removal is also buggier. It never supported
software cursors drawn into the border, and the hardware cursor is
probably broken by other bugs to be fixed soon.

------------------------------------------------------------------------
r316733 | bde | 2017-04-12 16:21:55 +0000 (Wed, 12 Apr 2017) | 45 lines

Fix clobbering of the default attribute and the screen position in
scteken_init(). Move the internals of scteken_sync() into a local
function to help do this.

scteken_init() reset or adjusted the default attribute and screen
position at least 3 and 5 times, respectively. Warm init shouldn't
do any more than reset the "input" state.
(scterm-sc.c (which still works after minor editing), only resets
the escape state and the saved cursor position, and then does a
nearly-null sync of the current color.)

This mainly broke mode changes, and was most noticeable when the
background color is not teken's default (usually black). Then the
screen gets cleared in the wrong color. vidcontrol restores the
default normal attribute and tries to restore the default reverse
attribute. vidcontrol doesn't clear the screen again after restoring
the attribute(s), and it is too late to do it there without flicker.
Now the default normal attribute is restored before the change affects
the rendering.

When the foreground color is not teken's default, clearing with the
wrong attributes gave strange cursor colors for some cursor types.

The default reverse attribute is not restored since it is unsupported.

2/3 of the clobbering was from 2 resetting window resizing calls. The
second one is needed to restore the size, but must not reset. Window
resizing also sanitizes the cursor position, and after the main reset
resets the window size, the cursor row would often be adjusted from
24 to 23 if it were not already reset to 0. scteken_sync() is good
for restoring the window size and the cursor position in the correct
order, but was unusable at init time since scp->ts is not always
initialized then. Adjust to use its internals.

I didn't notice any problems from the cursor reset. The cursor should
be reset, and a previous fix was to reset it consistently a little
later.

Doing nothing for warm init works almost as well, if not better. It
is not very useful to reset the escape state for mode changes, since
the reset is especially likely to be null then. The escape state is
most likely to be non-initial and corrupted by its most normal uses
-- sloppy non-atomic output where a context switch or just mixing
stdout with stderr splits up escape sequences.

------------------------------------------------------------------------
r316737 | bde | 2017-04-12 18:52:06 +0000 (Wed, 12 Apr 2017) | 23 lines

Fix removal of mouse image by the vga planar renderer in the right border
in unusual cases. Optimize and significantly clean up removal in this
renderer. Optimize removal in the vga direct renderer.

Removal only needs to be done in the border (the part with pixels) in
both cases. The planar renderer used the condition scp->xoff > 0 to
test whether a right border exists. This actually tests for a left
border, and when the total horizontal border is 8 pixels, rounding gives
only a right border. This was the unusual broken case. An example
is easy to configure using something like "vidcontrol -f 8x16 iso-8x16
-g 79x25 MODE_27".

Optimize the planar case a little by only removing 9x13 active pixels
out of 16x16. Optimize it a lot by not doing anything if there is no
overlap with the border. Don't unroll the main loop or hard-code so
many assumptions about font sizes in it. On my Haswell system, graphics
memory and i/o accesses takes about 520 cycles each so optimizations from
unrolling are in the noise.

Optimize the direct case to not do anything if there is no overlap with
the border. Do a sanity check on the saveunder's coordinates. This
requires a previous change to pass non-rounded coordinates.

------------------------------------------------------------------------
r316741 | bde | 2017-04-12 20:18:38 +0000 (Wed, 12 Apr 2017) | 24 lines

Improve drawing of the vga planar mode mouse image a little. Unobfuscate
the method a lot.

Reduce the AND mask to the complement of the cursor's frame, so that area
inside the frame is not drawn first in black and then in lightwhite. The
AND-OR method is only directly suitable for the text mouse image, since
it doesn't go to the hardware there. Planar mode Mouse cursor drawing
takes 10-20 usec on my Haswell system (approx. 100 graphics accesses
at 130 nsec each), so the transient was not visible.

The method used the fancy read mode 1 and its color compare and color
don't care registers with value 0 in them so that all colors matched.
All that this did was make byte reads of frame buffer memory return 0xff,
so that the x86 case could obfuscate read+write as "and". The read must
be done for its side effect on the graphics controller but is not used,
except it must return 0xff to avoid affecting the write when the write
is obfuscated as a read-modify-write "and". Perhaps that was a good
optimization for 8088 CPUs where each extra instruction byte took as
long as a byte memory access.

Just use read+write after removing the fancy read mode. Remove x86
ifdefs that did the "and". After removing the "and" in the non-x86
part of the ifdefs, fix 4 of 6 cases where the shift was wrong.

------------------------------------------------------------------------
r316827 | bde | 2017-04-14 12:03:34 +0000 (Fri, 14 Apr 2017) | 19 lines

Further unobfuscate the method of drawing the mouse cursor in vga planar
mode.

Don't manually unroll the 2 inner loops. On Haswell, doing so gave a
speedup of about 0.5% (about 4 cycles per iteration out of 1400), but
hard-coded a limit of width 9 and made better better optimizations
harder to see. gcc-4.2.1 -O does the unrolling anyway, unless tricked
with a volatile hack. gcc's unrolling is not very good and gives a
a speedup of about half as much (about 2 cycles per iteration). (All
timing on i386.)

Manual unrolling was only feasible because the inner loop only iterates
once or twice. Usually twice, but a dynamic check is needed to decide,
and was not moved from the second-innermost loop manually or by gcc.
This commit basically adds another dynamic check in the inner loop.

Cursor widths of 10-17 require 3 iterations in the inner loop and this
is not so easy to unroll -- even gcc stops at 2.

------------------------------------------------------------------------
r316830 | bde | 2017-04-14 14:00:13 +0000 (Fri, 14 Apr 2017) | 13 lines

Optimize drawing of the mouse cursor in vga planar mode almost as
much as possible, by avoiding null ANDs and ORs to the frame buffer.

Mouse cursors are fairly sparse, especially for their frame. Pixels
are written in groups of 8 in planar mode and the per-group sparseness
is not as large, but it still averages about 40% with the current
9x13 mouse cursor. The average drawing time is reduced by about this
amount (from 22 usec constant to 12.5 usec average on Haswell).

This optimization is relatively larger with larger cursors. Width 10
requires 6 frame buffer accesses per line instead of 4 if not done
sparsely, but rarely more than 4 if done sparsely.

------------------------------------------------------------------------
r316865 | bde | 2017-04-14 17:02:24 +0000 (Fri, 14 Apr 2017) | 10 lines

Adjust shifting so that cursor widths up to 17 (was 9) work in vga planar
mode.

Direct mode always supported widths up to 32, except for its hard-coded
16s matching the pixmap size. Text mode is still limited to 9 its 2x2
character cell method and missing adjustments for the gap between
characters, if any.

Cursor heights can be almost anything in graphics modes.

MFC r316136:

The switch to kernel terminal context needs to update more than the cursor
position. Especially the screen size, and potentially everything except
the input state and attributes. Do this by changing the cursor position
setting method to a general syncing method.

Use proper constructors instead of copying to create kernel terminal
contexts. We really want clones and not new instances, but there is
no method for cloning and there is nothing in the active instance that
needs to be cloned exactly.

Add proper destructors for kernel terminal contexts. I doubt that the
destructor code has every been reached, but if it was then it leaked the
memory of the clones.

Remove freeing of statically allocated memory for the non-kernel terminal
context for the same terminal as the kernel. This is in the nearly
unreachable code. This used to not happen because delicate context
swapping made the user context use the dynamic memory and kernel
context the static memory. I didn't restore this swapping since it
would have been unnatural to have all kernel contexts except 1 dynamic.

The constructor for terminal context has bad layering for reasons
related to the bug. It has to return static memory early before
malloc() works. Callers also can't allocate memory until after the
first constructor selects an emulator and tells upper layers the size
of its context. After that, the cloning hack required the cloning
code to allocate the memory, but for all other constructors it would
be better for the terminal layer to allocate and deallocate the
memory in all cases.

Zero the memory when allocating terminal contexts dynamically.

MFC r315984:

Restore switching to a separate kernel terminal "input" state and extend
it to a separate state for each CPU.

Terminal "input" is user or kernel output. Its state includes the current
parser state for escape sequences and multi-byte characters, and some
results of previous parsing (mainly attributes), and in teken the cursor
position, but not completed output. This state must be switched for kernel
output since the kernel can preempt anything, including itself, and this
must not affect the preempted state more than necessary. Since vty0 is
shared, it is necessary to affect the frame buffer and cursor position and
history, but escape sequences must not be affected and attributes for
further output must not be affected.

This used to work. The syscons terminal state contained mainly the parser
state for escape sequences and attributes, but not the cursor position,
and was switched. This was first broken by SMP and/or preemptive kernels.
Then there should really be a separate state for each thread, and one more
for ddb, or locking to prevent preemption. Serialization of printf() helps.
But it is arcane that full syscons escape sequences mostly work in kernel
printf(), and I have never seen them used except by me to test this fix.
They worked perfectly except for the races, since "input" from the kernel
was not special in any way.

This was broken to use teken. The general switch was removed, and the
kernel normal attribute was switched specially. The kernel reverse
attribute (config option SC_CONS_REVERSE_ATTR) became unused, and is
still unusable because teken doesn't support default reverse attributes
(it used to only be used via the ANSI escape sequence to set reverse
video).

The only new difficulty for using teken seems to be that the cursor
position is in the "input" state, so it must be updated in the active
input state for each half of the switch. Do this to complete the
restoration.

The per-CPU state is mainly to make per-CPU coloring work cleanly, at
a cost of some space. Each CPU gets its own full set of attribute
(not just the current attribute) maintained in the usual way. This
also reduces races from unserialized printf()s. However, this gives
races for serialized printf()s that otherwise have none. Nothing
prevents the CPU doing the a printf() changing in the middle of an
escape sequence.

MFC r315003,r315065,r315066:

Rename scteken_revattr() to scteken_sc_to_te_attr(). scteken_revattr()
looked like it might handle reverse attributes, but it actually handles
conversion of attributes in the direction indicated by the new name.
Reverse attributes are just broken.

Rename scteken_attr() to scteken_te_to_sc_attr(). scteken_attr() looked
like it might give teken attributes, but it actually gives sc attributes.

Change scteken_te_to_sc_attr() to return int instead of unsigned int.
u_char would be enough, and it promotes to int, and syscons uses int
or u_short for its attributes everywhere else (u_short holds a shifted
form and it promotes to int too).

Add a scteken_set_cursor() (sc to teken) method and use it to fix
some cases of initialization and resetting of the teken cursor position.
(This bad name is consistent with others, but it is too easy to confuse
with scteken_cursor() which goes in the opposite direction.)

The following cases were broken:
- for booting without a syscons console, the teken and sc positions for
ttyv0 were (0, 0), but are supposed to be somewhere in the middle of
the screen (after carefully preserved BIOS and loader messages) (at
least if there is no mode switch that loses the messages).
- after mode switches, the screen is cleared and the cursor is supposed to
be moved to (0, 0), but it was only moved there for sc.

The following case was hacked to work:
- for booting with a syscons console, it was arranged that scteken_init()
for the console could see a nonzero cursor position and adjust, although
this broke the sc seeing it in the non-console case above.

Fix the attribute for scteken_clear() (change it back from the user
user default normal attribute to the current attribute).

This change only fixes a logic error. scterm_clear() used to be
used for terminal reset, but teken uses a general fill function for
that, leaving scterm_clear() only used for initialization and mode
change, when using the user default attribute is correct. It is not
really a terminal function, but needs to sync its changes with the
terminal layer. Syncing of the attribute is currently broken for
terminal reset, but works for initialization and mode change.

MFC r314641,r314646,r314997,r315390:

Colorize syscons kernel console output according to a table indexed
by the CPU number.

This was originally for debugging near-deadlock conditions where
multiple CPUs either deadlock or scramble each other's output trying
to report the problem, but I found it interesting and sometimes
useful for ordinary kernel messages. Ordinary kernel messages
shouldn't be interleaved, but if they are then the colorization
makes them readable even if the interleaving is for every character
(provided the CPU printing each message doesn't change).

The default colors are 8-15 starting at 15 (bright white on black)
for CPU 0 and repeating every 8 CPUs. This works best with 8 CPUs.
Non-bright colors and nonzero background colors need special
configuration to avoid unreadable and ugly combinations so are not
configured by default. The next bright color after 15 is 8 (bright
black = dark gray) is not very readable but is the only other color
used with 2 CPUs. After that the next bright color is 9 (bright
blue) which is not much brighter than bright black, but is used with
3+ CPUs. Other bright colors are brighter.

Colorization is configured by default so that it gets tested. It can
only be turned off by configuring SC_KERNEL_CONS_ATTR to anything other
than FG_WHITE. After booting, all colors can be changed using the
syscons.kattr sysctl. This is a SYSCTL_OPAQUE, and no utility is
provided to change it (sysctl only displays it).

The default colors work in all VGA modes that I could test. In 2-color
graphics modes, all 8 bright colors are displayed as bright white, so
the colorization has no effect, but anything with a nonzero background
gives white on white unless the foreground is zero. I don't have an
mono or VGA grayscale hardware to test on. Support for mono mode seems
to have never worked right in syscons (I think bright white gives white
underline with either bold or bright), but VGA grayscale should work
better than 2-color graphics.

Implement ec_putc() (emergency kernel [syscons] console putc()) and use
it in emergency in sc_cnputc().

Locking fixes in sc_cnputc() previously turned off normal output in
near-deadlock conditions and added deferred output which might never
be completed. Emergency output goes to the frame buffer using
sufficiently atomic non-blocking writes if the console is in text
mode (in graphics mode, nothing is done, modulo races setting the
graphics mode bit). Screen updates overwrite the emergency output
if the emergency condition clears enough to reach them.

ec_putc() also works for "early" console output in normal x86 text
mode as soon as this mode is initialized (if ever). This uses a
hard-coded x86 frame buffer address before cninit() and a hopefully
MI address after cninit(). But non-x86 is more likely to not support
text mode, when ec_putc() will be null. ec_putc() has no dependencies
of syscons before cninit(), and only has them later to track syscons'
mode changes. This commit doesn't attach ec_putc() for early use.

To test emergency use, put a breakpoint in central syscons output code
like sc_puts() and do some user output. The system used to race or
deadlock in ddb output soon after entry to ddb. The locking fixes
deferred the output until after leaving ddb, so ddb was unusable and
you had to try typing c[ontinue] blindly until it exited, or better use
a serial console in parallel. Now the output goes to a window in the
middle 2/3 of the screen. Scrolling is circular and there is no cursor,
but otherwise ec_putc() provides full dumb terminal functionality and
very fast output that hides artificates from dumb overwrites.

MFC r305121,r305231:

Add some locking to sc_cngetc().

Keyboard input needs Giant locking, and that is not possible to do
correctly here. Use mtx_trylock() and proceed unlocked as before if
we can't acquire Giant (non-recursively), except in kdb mode don't
even try to acquire Giant. Everything here is a hack, but it often
works. Even if mtx_trylock() succeeds, this might be a LOR.

Keyboard input also needs screen locking, to handle screen updates
and switches. Add this, using the same simplistic screen locking
as for sc_cnputc().

Giant must be acquired before the screen lock, and the screen lock
must be dropped when calling the keyboard driver (else it would get a
harmless LOR if it tries to acquire Giant). It was intended that sc
cn open/close hide the locking calls, and they do for i/o functions
functions except for this complication.

Non-console keyboard input is still only Giant-locked, with screen
locking in some called functions. This is correct for the keyboard
parts only.

When Giant cannot be acquired properly, atkbd and kbdmux tend to race
and work (they assume that the caller acquired Giant properly and don't
try to acquire it again or check that it has been acquired, and the
races rarely matter), while ukbd tends to deadlock or panic (since it
does the opposite, and has other usb threads to deadlock with).

The keyboard (Giant) locking here does very little, but the screen
locking completes screen locking for console mode except for not
detecting or handling deadlock.

The log message for the previous commit didn't mention the most the
important detail that sc_cngetc() now opens and closes the keyboard
on every call again. This was moved from sc_cngetc() to scn_cngrab/
ungrab() in r228644, but the change wasn't quite complete. After
fixes for nesting in kbdd_poll() in ukbd and kbdmux, these opens
and closes should have no significant effect if done while grabbed.
They fix unusual cases when cngetc() is called while not grabbed.

This commit is the main fix for screen locking in sc_cnputc():
detect deadlock or likely-deadlock and handle it by buffering the
output atomically and printing it later if the deadlock condition
clears (and sc_cnputc() is called).

The most common deadlock is when the screen lock is held by ourself.
Then it would be safe to acquire the lock recursively if the console
driver is calling printf() in a safe context, but we don't know when
that is. It is not safe to ignore the lock even in kdb or panic mode.
But ignore it in panic mode. The only other known case of deadlock
is when another thread holds the lock but is running on a stopped CPU.
Detect that case approximately by using trylock and retrying for 1000
usec. On a 4 GHz CPU, 100 usec is almost long enough -- screen switches
take slightly longer than that. Not retrying at all is good enough
except for stress tests, and planned future versions will extend the
timeout so that the stress tests work better.

To see the behaviour when deadlock is detected, single step through
sctty_outwakeup() (or sc_puts() to start with deadlock). Another
(serial) console is needed to the buffered-only output, but the
keyboard works in this context to continue or step out of the
deadlocked region. The buffer is not large enough to hold all the
output for this.

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r304804:

Less-quick fix for locking fixes in r172250. r172250 added a second
syscons spinlock for the output routine alone. It is better to extend
the coverage of the first syscons spinlock added in r162285. 2 locks
might work with complicated juggling, but no juggling was done. What
the 2 locks actually did was to cover some of the missing locking in
each other and deadlock less often against each other than a single
lock with larger coverage would against itself. Races are preferable
to deadlocks here, but 2 locks are still worse since they are harder
to understand and fix.

Prefer deadlocks to races and merge the second lock into the first one.

Extend the scope of the spinlocking to all of sc_cnputc() instead of
just the sc_puts() part. This further prefers deadlocks to races.

Extend the kdb_active hack from sc_puts() internals for the second lock
to all spinlocking. This reduces deadlocks much more than the other
changes increases them. The s/p,10* test in ddb gets much further now.
Hide this detail in the SC_VIDEO_LOCK() macro. Add namespace pollution
in 1 nested #include and reduce namespace pollution in other nested
#includes to pay for this.

Move the first lock higher in the witness order. The second lock was
unnaturally low and the first lock was unnaturally high. The second
lock had to be above "sleepq chain" and/or "callout" to avoid spurious
LORs for visual bells in sc_puts(). Other console driver locks are
already even higher (but not adjacent like they should be) except when
they are missing from the table. Audio bells also benefit from the
syscons lock being high so that audio mutexes have chance of being
lower. Otherwise, console drviver locks should be as low as possible.
Non-spurious LORs now occur if the bell code calls printf() or is
interrupted (perhaps by an NMI) and the interrupt handler calls
printf(). Previous commits turned off many bells in console i/o but
missed ones done by the teken layer.

MFC r304773,r304800:

Flesh out the state and flags args to sccnopen(). Set state flags to
indicate (potentially partial) success of the open. Use these to
decide what to close in sccnclose(). Only grab/ungrab use open/close
so far.

Add a per-sc variable to count successful keyboard opens and use
this instead of the grab count to decide if the keyboad state has
been switched.

Start fixing the locking by using atomic ops for the most important
counter -- the grab level one. Other racy counting will eventually
be fixed by normal mutex or kdb locking in most cases.

Use a 2-entry per-sc stack of states for grabbing. 2 is just enough
to debug grabbing, e.g., for gets(). gets() grabs once and might not
be able to do a full (or any) state switch. ddb grabs again and has
a better chance of doing a full state switch and needs a place to
stack the previous state. For more than 3 levels, grabbing just
changes the count. Console drivers should try to switch on every i/o
in case lower levels of nesting failed to switch but the current level
succeeds, but then the switch (back) must be completed on every i/o
and this flaps the state unless the switch is null. The main point
of grabbing is to make it null quite often. Syscons grabbing also
does a carefully chosen screen focus that is not done on every i/o.

Add a large comment about grabbing.

Restore some small lost comments.

MFC r304173,r304181,r304186:

Fix restoring the kbd_mode part of the keyboard state in grab/ungrab.
Simply change the mode to K_XLATE using a local variable and use the
grab level as a flag to tell screen switches not to change it again,
so that we don't need to switch scp->kbd_mode. We did the latter,
but didn't have the complications to update the keyboard mode switch
for every screen switch. sc->kbd_mode remains at its user setting
for all scp's and ungrabbing restores to it.

Restructure the grabbing functions into mere wrappers of new open and
close functions. Scattered calls to sc_cnputc() and sc_cngetc() were
broken by turning the semi-reentrant inline context-switching code in
these functions into the grabbing functions. cncheckc() calls for
panic dumps are the main broken case. The grabbing functions have
special behaviour (mainly screen switching in sc_cngrab()) which makes
them unsuitable as replacements for the inline code.

Clean up the new sc cn open and close functions (old sc cn grab and ungrab
functions). Mainly, spell sc as itself instead of as scp->sc.

MFC r304165,r304166:

Like scr_lock, the grab count needs to be per-physical-device to work.

This bug corrupted the grab count on both vtys if the ungrabbed vty is
different from the console, and failed to restore the keyboard state
on the ungrabbed vty, but not restoring the latter usually left the
keyboard mode part of it uncorrupted at 1 (K_XLATE), while after this
fix the keyboard mode part is usually corrupted to 0 (K_RAW).

While here, rename the grab count from 'grabbed' to grab_level.

MFC r304153:

Quick fix for locking fixes in r172250. The lock added there was per-
virtual-device, but needs to be per-physical-device so that it protects
shared data. Usually, scp->sc->write_in_progress got corrupted first
and further corruption was limited when this variable was left at nonzero
with no write in progress.

Attempt to fix missing lock destruction in r162285. Put it with the
lock destruction for r172250 after moving the latter. Both might be
unreachable.

To demonstrate the bug, find a buggy syscall or sysctl that calls
printf(9) and run this often. Run hd /dev/zero >/dev/ttyvN for any
N != 0. The console spam goes to ttyv0 and the non-console spam goes
to ttyvN, so the lock provided no protection (but it helped for
N == 0).

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Fix comment introduced in r262480: it's 1920x1200, not 1980x1200.

PR: kern/180558
MFC after: 5 days

Increase maximum number of columns to support 1980x1200 displays.

In my specific case, this fixes the problem of my PowerMac G5 displaying a
4:3 console on a 16:10 display with black bars on the left and right.

PR: kern/180558
Reviewed by: nwhitehorn
MFC after: 5 days

MFcalloutng (r244249, r244306 by mav):
- Switch syscons from timeout() to callout_reset_flags() and specify that
precision is not important there -- anything from 20 to 30Hz will be fine.
- Reduce syscons "refresh" rate to 1-2Hz when console is in graphics mode
and there is nothing to do except some polling for keyboard. Text mode
refresh would also be nice to have adaptive, but this change at least
should help laptop users who running X.

Sponsored by: Google Summer of Code 2012, iXsystems inc.
Tested by: flo, marius, ian, markj, Fabian Keil

Convert files to UTF-8

syscons: provide a first iteration of cngrab/cnungrab implementation

- put underlying keyboard(s) into the polling mode for the whole
duration of the grab, instead of the previous behavior of going into
and out of the polling mode around each polling attempt
- ditto for setting K_XLATE mode and enabling a disabled keyboard

Inspired by: bde
MFC after: 2 months

syscons: make sc_puts static as it is used only privately

Perhaps sc_puts should also be renamed to scputs to follow the implied
naming conventions in the file...

MFC after: 2 weeks

Add support for alternative break-to-debugger to syscons(4). While most
keyboards allow console break sequences (such as ctrl-alt-esc) to be
entered, alternative break can prove useful under virtualisation and
remote console systems where entering control sequences can be
difficult or unreliable.

MFC after: 3 weeks
Approved by: re (bz)

Move VT switching hack for suspend/resume from bus drivers to syscons.c
using event handlers. A different version was

Submitted by: Taku YAMAMOTO (taku at tackymt dot homeip dot net)

Suspend screen updates when the video controller is powered down.

Improve VESA mode switching via loader tunable `hint.sc.0.vesa_mode'.
The most notable change is history buffer is fully saved/restored now.

Yet another attempt to make palette loading more safer:

- Add a separate palette data for 8-bit DAC mode when SC_PIXEL_MODE is set
and fill it up with default gray-scale palette data for text. Now we don't
have to set `hint.sc.0.vesa_mode' to get the default palette data.
- Add a new adapter flag, V_ADP_DAC8 to track whether the controller is
using 8-bit palette format and load correct palette when switching modes.
- Set 8-bit DAC mode only for non-VGA compatible graphics mode.

Allow Syscons terminal emulators to provide function key strings.

xterm and cons25 have some incompatibilities when it comes to escape
sequences for special keys, such as F1 to F12, home, end, etc. Add a new
te_fkeystr() that can be used to override the strings.

scterm-sck won't do anything with this, but scterm-teken will use
teken_get_sequences() to obtain the proper sequence.

Add support for VT200-style mouse input.

Right now if applications want to use the mouse on the command line,
they use sysmouse(4) and install a signal handler in the kernel to
deliver signals when mouse events arrive. This conflicts with my plan to
change to TERM=xterm, so implement proper VT200-style mouse input.

Because mouse input is now streamed through the TTY, it means you can
now SSH to another system on the console and use the mouse there as
well. The disadvantage of the VT200 mouse protocol, is that it doesn't
seem to generate events when moving the cursor. Only when pressing and
releasing mouse buttons.

There are different protocols as well, but this one seems to be most
commonly supported.

Reported by: Paul B. Mahol <onemda gmail com>
Tested with: vim(1)

Extend the usage of sc(4)'s hint variable 'flag'. Bit 0x80 now means
"set vesa mode" and higher 16bits of the flag would be the desired mode.

One can now set, for instance, hint.sc.0.flags=0x01680180, which means
that the system should set VESA mode 0x168 upon boot.

Submitted by: paradox <ddkprog yahoo com>, swell k at gmail.com with
some minor changes.

Make a 1:1 mapping between syscons stats and terminal emulators.

After I imported libteken into the source tree, I noticed syscons didn't
store the cursor position inside the terminal emulator, but inside the
virtual terminal stat. This is not very useful, because when you
implement more complex forms of line wrapping, you need to keep track of
more state than just the cursor position.

Because the kernel messages didn't share the same terminal emulator as
ttyv0, this caused a lot of strange things, like kernel messages being
misplaced and a missing notification to resize the terminal emulator for
kernel messages never to be resized when using vidcontrol.

This patch just removes kernel_console_ts and adds a special parameter
to te_puts to determine whether messages should be printed using regular
colors or the ones for kernel messages.

Reported by: ache
Tested by: nyan, garga (older version)

Replace syscons terminal renderer by a new renderer that uses libteken.

Some time ago I started working on a library called libteken, which is
terminal emulator. It does not buffer any screen contents, but only
keeps terminal state, such as cursor position, attributes, etc. It
should implement all escape sequences that are implemented by the
cons25 terminal emulator, but also a fair amount of sequences that are
present in VT100 and xterm.

A lot of random notes, which could be of interest to users/developers:

- Even though I'm leaving the terminal type set to `cons25', users can
do experiments with placing `xterm-color' in /etc/ttys. Because we
only implement a subset of features of xterm, this may cause
artifacts. We should consider extending libteken, because in my
opinion xterm is the way to go. Some missing features:

- Keypad application mode (DECKPAM)
- Character sets (SCS)

- libteken is filled with a fair amount of assertions, but unfortunately
we cannot go into the debugger anymore if we fail them. I've done
development of this library almost entirely in userspace. In
sys/dev/syscons/teken there are two applications that can be helpful
when debugging the code:

- teken_demo: a terminal emulator that can be started from a regular
xterm that emulates a terminal using libteken. This application can
be very useful to debug any rendering issues.

- teken_stress: a stress testing application that emulates random
terminal output. libteken has literally survived multiple terabytes
of random input.

- libteken also includes support for UTF-8, but unfortunately our input
layer and font renderer don't support this. If users want to
experiment with UTF-8 support, they can enable `TEKEN_UTF8' in
teken.h. If you recompile your kernel or the teken_demo application,
you can hold some nice experiments.

- I've left PC98 the way it is right now. The PC98 platform has a custom
syscons renderer, which supports some form of localised input. Maybe
we should port PC98 to libteken by the time syscons supports UTF-8?

- I've removed the `dumb' terminal emulator. It has been broken for
years. It hasn't survived the `struct proc' -> `struct thread'
conversion.

- To prevent confusion among people that want to hack on libteken:
unlike syscons, the state machines that parse the escape sequences are
machine generated. This means that if you want to add new escape
sequences, you have to add an entry to the `sequences' file. This will
cause new entries to be added to `teken_state.h'.

- Any rendering artifacts that didn't occur prior to this commit are by
accident. They should be reported to me, so I can fix them.

Discussed on: current@, hackers@
Discussed with: philip (at 25C3)

Integrate the new MPSAFE TTY layer to the FreeBSD operating system.

The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.

If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).

The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan

Mark the syscons video spin mutex as recursable since it is currently
recursed in a few places.

MFC after: 1 week

Remove explicit calls to keyboard methods with their respective variants
implemented with macros. This patch improves code readability. Reasoning
behind kbdd_* is a "keyboard discipline".

List of macros is supposed to be complete--all methods of keyboard_switch
should have their respective macros from now on.

Functionally, this code should be no-op. My intention is to leave current
behaviour of code as is.

Glanced at by: rwatson
Reviewed by: emax, marcel
Approved by: cognet

Serialize output routine of terminal emulator (te_puts()) by a lock.
- The output routine of low level console is not protected by any lock
by default.
- Increment and decrement of sc->write_in_progress are not atomic and
this may cause console hang.
- We also have many other states used by emulator that should be protected
by the lock.
- This change does not fix interspersed messages which PRINTF_BUFR_SIZE
kernel option should fix.

Approved by: re (bmah)
MFC after: 1 week

Introduce a spinlock for synchronizing access to the video output hardware
in syscons. This replaces a simple access semaphore that was assumed to be
protected by Giant but often was not. If two threads that were otherwise
SMP-safe called printf at the same time, there was a high likelyhood that
the semaphore would get corrupted and result in a permanently frozen video
console. This is similar to what is already done in the serial console
drivers.

Remove various bits of conditional Alpha code and fixup a few comments.

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.
This API breakage is committed now so it can be MFC'ed in time for 6.0
and later on upcoming framebuffer drivers destined for use on sparc64
and which are expected to rely on using font loading internally and on
a syscons(4)-supplied mouse pointer image can be easily MFC'ed to
RELENG_6 rather than requiring a backport.

Tested on: i386, sparc64, make universe
MFC after: 1 week

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>
MFC after: 2 days

Add VESA mode support for syscons, which enables the support of 15, 16,
24, and 32 bit modes. To use that, syscons(4) must be built with
the compile time option 'options SC_PIXEL_MODE', and VESA support (a.k.a.
vesa.ko) must be either loaded, or be compiled into the kernel.

Do not return EINVAL when the mouse state is changed to what it already is,
which seems to cause problems when you have two mice attached, and
applications are not likely obtain useful information through the EINVAL
caused by showing the mouse pointer twice.

Teach vidcontrol(8) about mode names like MODE_<NUMBER>, where <NUMBER> is
the video mode number from the vidcontrol -i mode output. Also, revert the
video mode if something fails.

Obtained from: DragonFlyBSD
Discussed at: current@ with patch attached [1]
PR: kern/71142 [2]
Submitted by: Xuefeng DENG <dsnofe at msn com> [1],
Cyrille Lefevre <cyrille dot lefevre at laposte dot net> [2]

On sparc64 use 'syscons' rather than 'sc' for SC_DRIVER_NAME so
syscons(4) and its pseudo-devices don't get confused (including by
other device drivers) with the system controller devices which are
also termed 'sc' in the OFW tree (and which we probably want to
interface with hwpmc(4) one day).

Change a directory layout for pc98.
- Move MD files into <arch>/<arch>.
- Move bus dependent files into <arch>/<bus>.
Rename some files to more suitable names.

Repo-copied by: peter
Discussed with: imp

Avoid casts as lvalues.

Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".

Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.

- Add a font width field to struct scr_stat. Use this instead of '8'.
- Use the values in the video info for the font size and width instead
of second guessing.

Add sparc64 ifdefs.

Add a VT_LOCKSWITCH ioctl that disallows vty switching. Something
like this can be emulated by VT_SETMODEing to VT_PROCESS and never
releasing the vty, but this has a number of problems, most notably
that a process must stay resident for the lock to be in effect.

Reviewed by: roam, sheldonh

Turn on TGA support.

Submitted by: Andrew M. Miklic <AndrwMklc@cs.com>

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Fix some malformed macro concatenation that gcc-3 has objections about.

Refine cursor type/shape control escape sequences and
ioctls. We can now add ve, vi and vs capabilities to
cons25 in termcap.

Discussed with and tested by: ache

Fix dependencies between kernel options:
- When both SC_PIXEL_MODE and SC_NO_FONT_LOADING are defined,
quietly drop SC_NO_FONT_LOADING, because the pixel(raster)
console requires font.
- When SC_NO_FONT_LOADING is defined, force SC_ALT_MOUSE_IMAGE.
Without font, the arrow-shaped mouse cursor cannot be drawn.
- Fiddle and simplify some internal macros.
MFC after: 2 weeks

Remove the resume method. It is not necessary any more, because
keyboard drivers have it now...
MFC after: 4 weeks

Don't free buffers we didn't allocate.
MFC after: 2 weeks

With this commit, I hereby pronounce gensetdefs past its use-by date.

Replace the a.out emulation of 'struct linker_set' with something
a little more flexible. <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.

The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).

The macros declare a strongly typed set. They return elements with the
type that you declare the set with, rather than a generic void *.

For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>). Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.

For a.out, we use the old linker_set struct.

NOTE: the item lists are no longer null terminated. This is why
the code impact is high in certain areas.

The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.

linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.

Reviewed by: eivind

Make the beep duration independent of HZ.

PR: 25201
Submitted by: Akio Morita amorita@meadow.scphys.kyoto-u.ac.jp
MFC after: 1 week

Implement keyboard paste

PR: 25499
Submitted by: Gaspar Chilingarov <nm@web.am>

Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by: msmith and others

Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by: phk
Reviewed by: phk
Approved by: mdodd

Unbreak LINT.

- Fix SC_ALT_MOUSE_IMAGE; don't blink the mouse cursor.
- Fix non-destructive, underline text cursor.

Unconditionally define sc_paste().

Fix wrong usage of FONT_NONE. It was not meant to be set in
scp->font_size in the first place. It is redundant now and is
removed.

Found by: bde

This is the 3rd stage of syscons code reorganization.

- Split terminal emulation code from the main part of the driver so
that we can have alternative terminal emulator modules if we like in
the future. (We are not quite there yet, though.)

- Put sysmouse related code in a separate file, thus, simplifying the
main part of the driver.

As some files are added to the source tree, you need to run config(8)
before you compile a new kernel next time.

You shouldn't see any functional change by this commit; this is only
internal code reorganization.

Make the mouse cursor char code configurable via the CONS_MOUSECTL
ioctl.

By popular demand.

This patch clears the way for removing a number of tty related
fields in struct cdevsw:

d_stop moved to struct tty.
d_reset already unused.
d_devtotty linkage now provided by dev_t->si_tty.

These fields will be removed from struct cdevsw together with
d_params and d_maxio Real Soon Now.

The changes in this patch consist of:

initialize dev->si_tty in *_open()
initialize tty->t_stop
remove devtotty functions
rename ttpoll to ttypoll
a few adjustments to these changes in the generic code
a bump of __FreeBSD_version
add a couple of FreeBSD tags

- Hang the scr_stat struct from dev_t.
- Remove sc_get_scr_stat(). It's not necessary anymore.
- Call ttymalloc() to allocate the struct tty for each vty, rather than
statically declaring an array of struct tty. We still need a statically
allocated struct tty for the first vty which is used for the kernel
console I/O, though.
- Likewise, call ttymalloc() for /dev/sysmouse and /dev/consolectl.
- Delete unnecessary test on the pointer struct tty *tp in some functions.
- Delete unused code in scmouse.c.

WARNING: this change requires you to recompile screen savers!

- Preserve the content of the back scroll buffer when changing the
video mode.

Requested by: a lot of people.
PR: kern/13764

$Id$ -> $FreeBSD$

Convert DEVFS hooks in (most) drivers to make_dev().

Diskslice/label code not yet handled.

Vinum, i4b, alpha, pc98 not dealt with (left to respective Maintainers)

Add the correct hook for devfs to kern_conf.c

The net result of this excercise is that a lot less files depends on DEVFS,
and devtoname() gets more sensible output in many cases.

A few drivers had minor additional cleanups performed relating to cdevsw
registration.

A few drivers don't register a cdevsw{} anymore, but only use make_dev().

First small steps at merging DEVFS and PHK's Dev_t stuff.

- Fixed memory leak in sc_alloc_history_buffer().
- Correctly observe the variable `extra_history_size' when changing
the size of history (scroll back) buffer.
- Added sc_free_history_buffer().

Pointed out by: des

Fix ESC[P (delete N chars) and ESC[@ (insert N chars). These deletion
and insertion should affect the line the cursor is on only.

This change should have been committed together with syscons.c rev 1.308.
(I forgot to do so, when I committed syscons.c :-(

Pointed out by: sos

The second phase of syscons reorganization.

- Split syscons source code into manageable chunks and reorganize
some of complicated functions.

- Many static variables are moved to the softc structure.

- Added a new key function, PREV. When this key is pressed, the vty
immediately before the current vty will become foreground. Analogue
to PREV, which is usually assigned to the PrntScrn key.
PR: kern/10113
Submitted by: Christian Weisgerber <naddy@mips.rhein-neckar.de>

- Modified the kernel console input function sccngetc() so that it
handles function keys properly.

- Reorganized the screen update routine.

- VT switching code is reorganized. It now should be slightly more
robust than before.

- Added the DEVICE_RESUME function so that syscons no longer hooks the
APM resume event directly.

- New kernel configuration options: SC_NO_CUTPASTE, SC_NO_FONT_LOADING,
SC_NO_HISTORY and SC_NO_SYSMOUSE.
Various parts of syscons can be omitted so that the kernel size is
reduced.

SC_PIXEL_MODE
Made the VESA 800x600 mode an option, rather than a standard part of
syscons.

SC_DISABLE_DDBKEY
Disables the `debug' key combination.

SC_ALT_MOUSE_IMAGE
Inverse the character cell at the mouse cursor position in the text
console, rather than drawing an arrow on the screen.
Submitted by: Nick Hibma (n_hibma@FreeBSD.ORG)

SC_DFLT_FONT
makeoptions "SC_DFLT_FONT=_font_name_"
Include the named font as the default font of syscons. 16-line,
14-line and 8-line font data will be compiled in. This option replaces
the existing STD8X16FONT option, which loads 16-line font data only.

- The VGA driver is split into /sys/dev/fb/vga.c and /sys/isa/vga_isa.c.

- The video driver provides a set of ioctl commands to manipulate the
frame buffer.

- New kernel configuration option: VGA_WIDTH90
Enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60. These
modes are mot always supported by the video card.
PR: i386/7510
Submitted by: kbyanc@freedomnet.com and alexv@sui.gda.itesm.mx.

- The header file machine/console.h is reorganized; its contents is now
split into sys/fbio.h, sys/kbio.h (a new file) and sys/consio.h
(another new file). machine/console.h is still maintained for
compatibility reasons.

- Kernel console selection/installation routines are fixed and
slightly rebumped so that it should now be possible to switch between
the interanl kernel console (sc or vt) and a remote kernel console
(sio) again, as it was in 2.x, 3.0 and 3.1.

- Screen savers and splash screen decoders
Because of the header file reorganization described above, screen
savers and splash screen decoders are slightly modified. After this
update, /sys/modules/syscons/saver.h is no longer necessary and is
removed.

Centralize and reorganize a few macros.

syscons
- Bring down the splash screen when a vty is opened for the first
time.
- Make sure the splash screen/screen saver is stopped before
switching vtys.
- Read and save initial values in the BIOS data area early.
VESA BIOS may change BIOS data values when switching modes.
- Fix missing '&' operator.
- Move ISA specific part of driver initialization to syscons_isa.c.

atkbd
- kbdtables.h is now in /sys/dev/kbd.

all
- Adjust for forthcoming alpha port. Submitted by: dfr

The first stage of console driver reorganization: activate new
keyboard and video card drivers.

Because of the changes, you are required to update your kernel
configuration file now!

The files in sys/dev/syscons are still i386-specific (but less so than
before), and won't compile for alpha and PC98 yet.

syscons still directly accesses the video card registers here and
there; this will be rectified in the later stages.

Yet another round of fixes for the VESA support code.

- Express various sizes in bytes, rather than Kbytes, in the video
mode and adapter information structures.
- Fill 0 in the linear buffer size field if the linear frame buffer
is not available.
- Remove SW_VESA_USER ioctl. It is still experimetal and was not meant
to be released.
- Fix missing cast operator.
- Correctly handle pointers returned by the VESA BIOS. The pointers
may point to the area either in the BIOS ROM or in the buffer supplied
by the caller.
- Set the destructive cursor at the right moment.

Fix destructive cursor shape after text mode switch.
This is only for standard modes, I don't check vesa modes yet.

- Use `u_long cmd' ioctl arg.
- Fix some external function declaration.
Submitted by: bde

Fix and update for VESA BIOS support in syscons.

- Handle pixel (raster text) mode properly.
- Clear screen and paint border right.
- Paint text attribute (colors).
- Fix off-by-one errors.
- Add some sanity checks.
- Fix some function prototypes.
- Add some comment lines.
- Define generic text mode numbers so that the user can just give
"80x25", "80x60", "132x25"..., rather than "VGA_xxx", to `vidcontrol'
to change the current video mode. `vidoio.c' and `vesa.c' will map
these numbers to real video mode numbers appropriate and available
with the given video hardware. I believe this will be useful to make
syscons more portable across archtectures.

Add VESA support to syscons.

Kazu writes:

The VESA support code requires vm86 support. Make sure your kernel
configuration file has the following line.
options "VM86"
If you want to statically link the VESA support code to the kernel,
add the following option to the kernel configuration file.
options "VESA"

The vidcontrol command now accepts the following video mode names:
VESA_132x25, VESA_132x43, VESA_132x50, VESA_132x60, VESA_800x600

The VESA_800x600 mode is a raster display mode. The 80x25 text will
be displayed on the 800x600 screen. Useful for some laptop computers.

vidcontrol accepts the new `-i <info>' option, where <info> must be
either `adapter' or `mode'. When the `-i adapter' option is given,
vidcontrol will print basic information (not much) on the video
adapter. When the `-i mode' option is specified, vidcontrol will
list video modes which are actually supported by the video adapter.

Submitted by: Kazutaka YOKOTA yokota@FreeBSD.ORG

1. Reorganized screen saver related code so that both the LKM screen
saver and splash screen can all work properly with syscons. Note that
the splash screen option (SC_SPLASH_SCREEN) does not work yet, as it
requires additional code from msmith.

- Reorganized the splash screen code to match the latest development
in this area.
- Delay screen switch in `switch_scr()' until the screen saver is
stopped, if one is running,
- Start the screen saver immediately, if any, when the `saver' key is
pressed. (There will be another commit for `kbdcontrol' to support
this keyword in the keymap file.)
- Do not always stop the screen saver when mouse-related ioctls
are called. Stop it only if the mouse is moved or buttons are
clicked; don't stop it if any other mouse ioctls are called.

2. Added provision to write userland screen savers. (Contact me if you
are interested in writing one.)

- Added CONS_IDLE, CONS_SAVERMODE, and CONS_SAVERSTART ioctls to
support userland screen savers.

3. Some code clean-ups.

- Add new bell types: "quiet.normal" and "quiet.visual".
When bell is of "quiet" types, the console won't ring (or flush)
if the ringing process is in a background vty.
PR: i386/2853

- Modify the escape sequence 'ESC[=%d;%dB' so that bell pitch and
duration are set in hertz and msecs by kbdcontrol(1).
There will be a corresponding kbdcontrol patch.
PR: bin/6037
Submitted by: Kouichi Hirabayashi (kh@eve.mogami-wire.co.jp)

Add support for VESA mode 0x102 (800x600x4) in syscons. You can activate
this using option "-b" to the boot blocks. It is smartest to compile
a font into your kernel (See LINT), but not mandatory, but apart from
the cursor you will see nothing on the screen until you load a font.

This mode allows XF86_VGA16 to run in 800x600 mode on otherwise unsupported
graphics hardware.

A number of buglets in the cursor handling in syscons may become
visible this way.

Make comp_vgaregs() less strict about VGA register values when
checking the BIOS video mode paramter table. Now syscons uses the
parameter table even if some bits in the table are different from the
current VGA register settings.

Even if comp_vgaregs() finds that the BIOS video parameter table looks
totally unfamiliar to it, syscons allows the user to change the
current video mode to some modes which are based on the VGA 80x25
mode. They are VGA 80x30, VGA 80x50, VGA 80x60. In this case the user
will be warned, during boot, that video mode switching is only
paritally supported on his machine.

PR: bin/4477

Reject unreasonable values passed to CONS_HISTORY ioctl. It did not
check the value and caused kernel panic when a large value was given.

- Move the configuration option SC_HISTORY_SIZE from syscons.h to
syscons.c.
- Define the maximum total number of history lines of all consoles.
It is SC_HISTORY_SIZE*MAXCONS or 1000*MAXCONS; whichever is larger.
CONS_HISTORY will allow the user to set the history size up to
SC_HISTORY_SIZE unconditionally (or the current height of the console
if it is larger than SC_HISTORY_SIZE). If the user requests a larger
buffer, it will be granted only if the total number of all allocated
history lines and the requested number of lines won't exceed the maximum.
- Don't free the previous history buffer and leave the history buffer
pointer holding a invalid pointer. Set the pointer to NULL first, then
free the buffer.

PR: bin/4592

Add a new keyboard mode K_CODE. Returns a single byte for each key
much like the scancode mode.
However the keys that (for no good reason) returns extension codes
etc, are translated into singlebyte codes.
Needed by libvgl. This makes life ALOT easier, also the XFree86
folks could use this.

Add a new compile option SC_HISTORY_SIZE to specify the history buffer
size in terms of lines (instead of bytes). When changing video mode
in ioctl SW_XXX commands, syscons checks scp->history_size and
allocate a history buffer at least as large as the new screen size.
(This was unnecessary before, because HISTORY_SIZE was as large as 100
lines and this is bigger than the maximum screen size: 60 lines).
Similar adjustment is done in ioctl CONS_HISTORY command too.

PR: kern/4169
Reviewed by: sos

Removed unused misplaced definition of TIMER_FREQ.

Use less-magic numbers in the definition of HISTORY_SIZE.

Screen saver related fixes.

1. Add new interface, add_scrn_saver()/remove_scrn_saver(), to declare
loading/unloading of a screen saver. The screen saver calls these
functions to notify syscons of loading/unloading events.

It was possible to load multiple savers each of which will try to
remember the previous saver in a local variable (`old_saver'). The
scheme breaks easily if the user load two savers and unload them in a
wrong order; if the first saver is unloaded first, `old_saver' in the
second saver points to nowhere.

Now only one screen saver is allowed in memory at a time.

Soeren will be looking into this issue again later. syscons is
becoming too heavy. It's time to cut things down, rather than adding
more...

2. Make scrn_timer() to be the primary caller of the screen saver
(*current_saver)(). scintr(), scioctl() and ansi_put() update
`scrn_time_stamp' to indicate that they want to stop the screen saver.

There are three exceptions, however.

One is remove_scrn_saver() which need to stop the current screen saver
if it is running. To guard against scrn_timer() calling the saver during
this operation, `current_saver' is set to `none_saver' early.

The others are sccngetc() and sccncheckc(); they will unblank the
screen too. When the kernel enters DDB (via the hot key or a
break point), the screen saver will be stopped by sccngetc().
However, we have a reentrancy problem here. If the system has been in
the middle of the screen saver...

(The screen saver reentrancy problem has always been with sccnputc()
and sccngetc() in the -current source. So, the new code is doing no
worse, I reckon.)

3. Use `mono_time' rather than `time'.

4. Make set_border() work for EGA and CGA in addition to VGA. Do
nothing for MDA.

Changes to the LKM screen saver modules will follow shortly. YOU NEED
TO RECOMPILE BOTH SCREEN SAVERS AND KERNEL AS OF THESE CHANGES.

Reviewed by: sos and bde

A fix/work-around for ThinkPad 535.

Add a new configuration flag, KBD_NORESET (0x20) to tell scprobe() not
to reset the keyboard.

IBM ThinkPad 535 has the `Fn' key with which the user can perform
certain functions in conjunction with other keys. For example, `Fn' +
PageUP/PageDOWN adjust speaker volume, `Fn' + Home/End change
brightness of LCD screen. It can also be used to suspend the system.

It appears that these functions are implemented at the keyboard level
or the keyboard controller level and totally independent from BIOS or
OS. But, if the keyboard is reset (as is done in scprobe()), they
become unavailable. (There are other laptops which have similar
functions associated with the `Fn' key. But, they aren't affected by
keyboard reset.)

ThinkPad 535 doesn't have switches or buttons to adjust brightness and
volume, or to put the system into the suspend mode. Therefore, it is
essential to preserve these `Fn' key functions in FreeBSD. The new
flag make scprobe() skip keyboard reset.

If this flag is not set, scprobe() behaves in the same say as before.

(If we only knew a way to detect ThinkPad 535, we could skip keyboard
reset automatically, but...)

1) font loading (two fixes)

When an ioctl command SW_XXXX is issued, scioctl() checks if the font
appropriate for the specified mode is already loaded. The check was
correctly done for 8 line and 16 line fonts, but not for 14 line font.

The symbols FONT_8, FONT_14 and FONT_16 were defined as numbers but
were sometimes treated as bit flags. They are now defined as bit
flags.

2) screen blinking (two fixes)

Removed a redundant call to timeout() in do_bell().

Don't let blink_screen() write to the video buffer if the screen is in
the graphics (UNKNOWN) mode.

3) screen saver timeout

The ioctl command CONS_BLANKTIME sets the screen saver's timeout. The
value of zero will disable the screen saver. If the screen saver is
currently running it should be stopped.

4) border color and destructive cursor (two fixes)

The border color and the cursor type can be changed via escape
sequences. But only VGA can change the border color and set the
cursor type to destructive (CHAR_CURSOR) in the current syscons.
scan_esc() failed to check this.

Reviewed by: sos

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

Add save/restore cursor as pr SCO screen(HW) manpage.
Fix ESC[2J to not move cursor home
Clear mouse cutmarking on more cases.
Minor changes by me.

Submitted by: ache

Upgrade the kbdio rutines to provide queued kbd & mouse events.
Minor other updates to syscons by me.

Submitted by: Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Allow us to enable the 'XT_KEYBOARD' code using a configuration flag.
This allows the user to add modify syscons's configuration flags using
UserConfig that will allow older/quirky hardware (most notably older IBM
ThinkPad laptops) to work with the standard boot kernel.

Inspired by: The Nomads

Remove SC_KBD_PROBE_WORKS option and replace it with a simple run-time flag
bit (0x0008) in the sc driver configuration line. This way it's easy to
boink a generic kernel.

Also, document and place in an opt_ file the #define's for overriding which
serial port is the system console.
Approved by: sos

Changed mouse functionality a bit, now the pointer disappears if
there is keyboard input.
The mousepointer is shown again immediately if moved.

Also a function pointer used to install a userwritten extra
ioctl handler (sc_user_ioctl). This way its is possible to
install user defined videomodes etc etc. No further changes
should be in the kernel.

Fix a couble of nasties regarding mouse pointer and different
resolutions.
Allow middle mouse button to be used for pasting.
Also added the beginnings of support for a splash page.

Fixed a couple of bugs in the mousepointer code.
Changed update strategy slightly.
Make set_mode & copy_font externally visible.

Fixed bug in pasting 8bit char (ache).
Added linefeeds in cuts that extend beyond one line.
Prepared for the mousefunctions to be used in nontext modes.

Change the way moused talk to syscons, now its only delivering mouseevents
via an ioctl (MOUSE_ACTION).
Fixed a couple of bugs (destructive cursor, uncut, jitter).
Now applications can use the mouse via the MOUSE_MODE ioctl, its
possible to have a signal sent on mouseevents, makeing an event loop
in the application take over mouseevents.

Moved declarations of static functions to the correct file. This fixes
hundreds of warnings from -Wunused in lkm/syscons/*.

Some news for syscons (long overdue):

Real support for a Textmode mousecursor, works by reprogramming the
charset. Together with this support for cut&paste in text mode.
To use it a userland daemon is needed (moused), which provides
the interface to the various mice protokols.
Bug fixes here and there, all known PR's closed by this update.

Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.

Staticize and cleanup.

Separate colors & attributes as Terry points
Reviewed by: soren

Added `#include "ioconf.h"' to <machine/conf.h> and cleaned up the
misplaced extern declarations (mostly prototypes of interrupt handlers)
that this exposed. The prototypes should be moved back to the driver
sources when the functions are staticalized.

Added idempotency guards to <machine/conf.h>. "ioconf.h" can't be
included when building LKMs so define a wart in bsd.kmod.mk to help
guard against including it.

Make pcvt and syscons live in the same kernel. If both are enabled, then
the first one in the config has priority. They can be switched using
userconfig().

i386/i386/conf.c:
Initialize the shared syscons/pcvt cdevsw entry to `nx'.

Add cdevsw registration functions.

Use devsw functions of the correct type if they exist.

i386/i386/cons.c:
Add renamed syscons entry points to constab.

i386/i386/cons.h:
Declare the renamed syscons entry points.

i386/i386/machdep.c:
Repeat console initialization after userconfig() in case the current
console has become wrong. This depends on cn functions not wiring down
anything important.

sys/conf.h:
Declare new functions.

i386/isa/isa.[ch]:
Add a function to decide which display driver has priority. Should be
done better.

i386/isa/syscons.c:
Rename pccn* -> sccn*.

Initialize CRTC start address in case the previous driver has moved it.

i386/isa/syscons.c, i386/isa/pcvt/*
Initialize the bogusly shared variable Crtat dynamically in case the
stored value was changed by the previous driver.

Initialize cdevsw table from a template.

Don't grab the console if another display driver has priority.

i386/isa/syscons.h, i386/isa/pcvt/pcvt_hdr.h:
Don't externally declare now-static cdevsw functions.

i386/isa/pcvt/pcvt_hdr.h:
Set the sensitive hardware flag so that pcvt doesn't always have lower
priority than syscons. This also fixes the "stupid" detection of the
display after filling the display with text.

i386/isa/pcvt/pcvt_out.c:
Don't be confused the off-screen cursor offset 0xffff set by syscons.

kern/subr_xxx.c:
Add enough nxio/nodev/null devsw functions of the correct type for syscons
and pcvt.

Fix races in scstart(). q_to_b() wasn't called at spltty(), so there
were two races:
- q_to_b() might unexpectedly return 0 (e.g, after a keyboard signal
flushes the output queue and isn't echoed). ansi_put() interprets
0 bytes as 4GB...
- more output (e.g. for echoes) might arrive afer q_to_b() returns 0.
Then scstart() returns presumably and the new output might not be
handled for a long time.

Remove unused function scxint().

Fix prototypes (foo() isn't a prototype).

Remove trailing whitespace.

Correct the type of the `c' arg to pccnputc().

Move declarations of console functions to cons.h so that they can't be
defined inconsistently in several places. They should be config(8)ed.

Fixes to the hardware cursor emulation.
Submitted by: ache

Emulate hw cursor closely, and get start&end scanlines from BIOS.

Optimized the way physical screen updates are done. Now only
update what has actually been touched. This should speed up
screen access on slow hardware.
Introduced setting of "destructive" cursor size, much like
the old hardware cursor.

Minor update to syscons.
Let "grey delete" be a function key (default is 0x7f)
Fix the xor cursor again..
Made the backspace key generate del as default
Made CTRL-space generate nul as default.

Incorporate bde's code-review comments.

(a) bring back ttselect, now that we have xxxdevtotty() it isn't dangerous.
(b) remove all of the wrappers that have been replaced by ttselect
(c) fix formatting in syscons.c and definition in syscons.h
(d) add cxdevtotty

NOT DONE:
(e) make pcvt work... it was already broken...when someone fixes pcvt to
link properly, just rename get_pccons to xxxdevtotty and we're done

(a) remove the pointer to each driver's tty structure array from cdevsw
(b) add a function callback vector to tty drivers that will return a pointer
to a valid tty structure based upon a dev_t
(c) make syscons structures the same size whether or not APM is enabled so
utilities don't crash if NAPM changes (and make the damn kernel compile!)
(d) rewrite /dev/snp ioctl interface so that it is device driver and i386
independant

Next syscons update (given up on numbering :)

Removed screensavers from syscons, they are now LKM's. This makes it
possible to do some really "interesting" screensavers...
Fixed bug that sometimes caused garbage to appear when leaving
"scroll-lock" history.
Reformattet indentation, it got too deep for a normal 80 pos screen.
Split up in syscons.c & syscons.h for use with the saver-lkm's.
Temporarily removed -s option from vidcontrol, savers should now
be loaded with modload.