vt/sc: retire logic to select vt(4) by default for UEFI boot

We previously defaulted to using sc(4) with a special case to prefer
vt(4) when booted via UEFI. As vt(4) is now always the default we can
simplify this.

Reviewed by: imp, kevans
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45356

cons: Add boot option to mute boot messages after banner

This is useful for embedded systems, where it provides feedback that the
kernel has booted, but avoids printing the probe messages. If both
mutemsgs and verbose are set, verbose cancels the mute.

Additionally, this unmutes the console on panic, so a user can see what
happened leading up to the panic.

Obtained from: Juniper Networks, Inc.

sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

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

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

Revert "Fill in cn_name in struct consdev."

This reverts commit 82a21151cf1d7a3e9e95b9edbbf74ac10f386d6a.

This commit was made to aid debugging before consoles are initialised so
that they can more easily be identified from a debugger. However,
various consoles (cfecons, ofwcons, mambocons and rcons) all check
whether cn_name[0] is non-zero to see they are attached or not, and so
this breaks that (perhaps misguided) approach. On RISC-V this results in
rcons (the SBI firmware console driver) racing with the real UART driver
and so input gets probabilistically lost on the real UART (around 2/3 of
the time for me on QEMU).

Moreover, the name given to CONSOLE_DRIVER isn't necessarily the same as
what eventually gets written to cn_name, such as cfecons vs cfe, rcons
vs riscv, ttyj0 vs aju, ttyv0 vs sc, ttyuN vs uart_phyp/opal and all
manner of things vs ucom, so in some cases this is in fact misleading as
the name will change after attaching.

Discussed with: cperciva

Fill in cn_name in struct consdev.

It makes debugging easier if the name is filled in from the start.

Reviewed by: imp
Sponsored by: https://www.patreon.com/cperciva
Differential Revision: https://reviews.freebsd.org/D35795

Re-implement virtual console (constty).

Protect conscallout with tty lock instead of Giant. In addition to
Giant removal it also closes race on console unset.

Introduce additional lock to protect against concurrent console sets.

Remove consbuf free on console unset as unsafe, making impossible to
change buffer size after first allocation. Instead increase default
buffer size from 8KB to 64KB and processing rate from 5Hz to 10-15Hz
to make the output more smooth.

MFC after: 1 month

sys/kern: quiet -Wwrite-strings

Quiet a variety of Wwrite-strings warnings in sys/kern at low-impact
sites. This patch avoids addressing certain others which would need to
plumb const through structure definitions.

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D23798

Replace ttyprintf with sbuf_printf and tty drain routine

Add string variants of cnputc and tty_putchar, and use them from the tty
sbuf drain routine.

Suggested by: ed@
Sponsored by: Dell EMC Isilon

add support for console resuming, implement it for uart, use on x86

This change adds a new optional console method cn_resume and a kernel
console interface cnresume. Consoles that may need to re-initialize
their hardware after suspend (e.g., because firmware does not care to do
it) will implement cn_resume. Note that it is called in rather early
environment not unlike early boot, so the same restrictions apply.
Platform specific code, for platforms that support hardware suspend,
should call cnresume early after resume, before any console output is
expected.

This change fixes a problem with a system of mine failing to resume when
a serial console is used. I found that the serial port was in a strange
configuration and an attempt to write to it likely resulted in an
infinite loop.

To avoid adding cn_resume method to every console driver, CONSOLE_DRIVER
macro has been extended to support optional methods.

Reviewed by: imp, mav
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D15552

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Prefer vt(4) for UEFI boot

The UEFI framebuffer driver vt_efifb requires vt(4), so add a mechanism
for the startup routine to set the preferred console. This change is
ugly because console init happens very early in the boot, making a
cleaner interface difficult. This change is intended only to facilitate
the sc(4) / vt(4) transition, and can be reverted once vt(4) is the
default.

Use a common tunable to choose between vt(4)/sc(4)

With this change and previous work from ray@ it will be possible to put
both in GENERIC, and have one enabled by default, but allow the other to
be selected via the loader.

(The previous implementation had separate kern.vt.disable and
hw.syscons.disable tunables, and would panic if both drivers were
compiled in and neither was explicitly disabled.)

MFC after: 1 week
Sponsored by: The FreeBSD Foundation

move GETS_*ECHO* defintions from libkern.h to cons.h

MFC after: 2 months

introduce cngets, a method for kernel to read a string from console

This is intended as a replacement for libkern's gets and mostly borrows
its implementation. It uses cngrab/cnungrab to delimit kernel's access
to console input.

Note: libkern's gets obviously doesn't share any bits of implementation
iwth libc's gets. They also have different APIs and the former doesn't
have the overflow problems of the latter.

Inspired by: bde
MFC after: 2 months

kern cons: introduce infrastructure for console grabbing by kernel

At the moment grab and ungrab methods of all console drivers are no-ops.

Current intended meaning of the calls is that the kernel takes control of
console input. In the future the semantics may be extended to mean that
the calling thread takes full ownership of the console (e.g. console
output from other threads could be suspended).

Inspired by: bde
MFC after: 2 months

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Allow multiple console devices per driver without insane code duplication.

Say, a driver wants to have multiple console devices to pick from, you
would normally write down something like this:

CONSOLE_DRIVER(dev1);
CONSOLE_DRIVER(dev2);

Unfortunately, this means that you have to declare 10 cn routines,
instead of 5. It also isn't possible to initialize cn_arg on beforehand.

I noticed this restriction when I was implementing some of the console
bits for my vt(4) driver in my newcons branch. I have a single set of cn
routines (termcn_*) which are shared by all vt(4) console devices.

In order to solve this, I'm adding a separate consdev_ops structure,
which contains all the function pointers. This structure is referenced
through consdev's cn_ops field.

While there, I'm removing CONS_DRIVER() and cn_checkc, which have been
deprecated for years. They weren't used throughout the source, until the
Xen console driver showed up. CONSOLE_DRIVER() has been changed to do
the right thing. It now declares both the consdev and consdev_ops
structure and ties them together. In other words: this change doesn't
change the KPI for drivers that used the regular way of declaring
console devices.

If drivers want to use multiple console devices, they can do this as
follows:

static const struct consdev_ops mydriver_cnops = {
.cn_probe = mydriver_cnprobe,
...
};
static struct mydriver_softc cons0_softc = {
...
};
CONSOLE_DEVICE(cons0, mydriver_cnops, &cons0_softc);
static struct mydriver_softc cons1_softc = {
...
};
CONSOLE_DEVICE(cons1, mydriver_cnops, &cons1_softc);

Obtained from: //depot/user/ed/newcons/...

Remove unused consdev structure fields.

The cn_unit and cn_tp fields don't seem to be used anywhere. Some
drivers set them, while others don't. Just remove them, in an attempt to
make our consdev code a little easier to understand.

- Import the HEAD csup code which is the basis for the cvsmode work.

Move TTY unrelated bits out of <sys/tty.h>.

For some reason, the <sys/tty.h> header file also contains routines of the
clists and console that are used inside the TTY layer. Because the clists
are not only used by the TTY layer (example: various input drivers), we'd
better move the entire clist programming interface into <sys/clist.h>. Also
remove a declaration of nonexistent variable.

The <sys/tty.h> header also contains various definitions for the console
code (tty_cons.c). Also move these to <sys/cons.h>, because they are
not implemented inside the TTY layer.

While there, create separate malloc pools for the clist and console code.

Approved by: philip (mentor)

Add a cnputs() function to write a string to the console with
a lock to prevent interspersed strings written from different CPUs
at the same time.

To avoid putting a buffer on the stack or having to malloc one,
space is incorporated in the per-cpu structure. The buffer
size if 128 bytes; chosen because it's the next power of 2 size
up from 80 characters.

String writes to the console are buffered up the end of the line
or until the buffer fills. Then the buffer is flushed to all
console devices.

Existing low level console output via cnputc() is unaffected by
this change. ithread calls to log() are also unaffected to avoid
blocking those threads.

A minor change to the behaviour in a panic situation is that
console output will still be buffered, but won't be written to
a tty as before. This should prevent interspersed panic output
as a number of CPUs panic before we end up single threaded
running ddb.

Reviewed by: scottl, jhb
MFC after: 2 weeks

Add new CONSOLE_DRIVER macro which takes just the name of the console
and constructs the member function names with CPPs' ##.

Do not include the checkc entry as it is going away.

GC the cn_dbctl_t hook for consoles, it is unused.

This used to make syscons switch to vty0 when we entered DDB but this
was lost in the KDB shuffle. We may want to bring it back down the road
but it should be done by calling cn_init_t/cn_term_t instead, possibly
with a flag argument saying "Debugger!"

/* -> /*- for license, minor formatting changes

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core

Rename cn_unavailable to cnunavailable for little more consistency.
Garbage collect unused cndebug() function.

Suggested by: bde

Eliminate global cons_unavailable flag and replace it by the status
bit maintained on a per-device basis. Single variable is inadequate
on machines running with multiple consoles enabled.

Add a new cn_flags fields to struct consdev, the low-level console
definition structure. Define one flag, CN_FLAG_NODEBUG, which
indicates the console driver cannot be used in the context of the
debugger. This may be used, for example, if the console device
interacts with kernel services that cannot be used from the
debugger context, such as the network stack. These drivers are
skipped over for calls to cn_checkc() and cn_putc(), and the
calling function simply moves on to the next available console.

Add a "low" console priority. This specifies that the console device
may have limited functionality and should only be used as a last resort,
perhaps only to tell the user that they should be using something else.

OK, I messed up /dev/console with what I had hoped would be compat
code. Convert remaining console drivers and hope for the best.

Add a cn_unit and cn_name field to the consdev structure.

Most of the actual use of the cn_dev field is merely to get the name,
and most of the actual initializations are bogusly using makedev()
because the probe/attach has not been completed.

Instead we will migrate console drivers to fill in the name and if
the driver needs it: the unit number, thereby avoiding the bogus
calls to makedev().

Change the console interface to pass a "struct consdev *" instead of a
dev_t to the method functions.

The dev_t can still be found at struct consdev *->cn_dev.

Add a void *cn_arg element to struct consdev which the drivers can use
for retrieving their softc.

Remove __P

Add new boot flag to i386 boot: -p.
This flag adds a pausing utility. When ran with -p, during the kernel
probing phase, the kernel will pause after each line of output.
This pausing can be ended with the '.' key, and is automatically
suspended when entering ddb.

This flag comes in handy at systems without a serial port that either hang
during booting or reser.
Reviewed by: (partly by jlemon)
MFC after: 1 week

Implement multiple low-level console support.

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

Add a new mechanism, cndbctl(), to tell the console driver that
ddb is entered. Don't refer to `in_Debugger' to see if we
are in the debugger. (The variable used to be static in Debugger()
and wasn't updated if ddb is entered via traps and panic anyway.)

- Don't refer to `in_Debugger'.
- Add `db_active' to i386/i386/db_interface.d (as in
alpha/alpha/db_interface.c).
- Remove cnpollc() stub from ddb/db_input.c.
- Add the dbctl function to syscons, pcvt, and sio. (The function for
pcvt and sio is noop at the moment.)

Jointly developed by: bde and me

(The final version was tweaked by me and not reviewed by bde. Thus,
if there is any error in this commit, that is entirely of mine, not
his.)

Some changes were obtained from: NetBSD

Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.

$Id$ -> $FreeBSD$

make alpha compile again.

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.

Fixed pedantic syntax errors caused by a trailing semicolon in a macro
definition.

Remove a hard-coded table of kernel console I/O functions exported
from sc, vt and sio drivers. Use instead a linker_set to collect them.

Staticize ??cngetc(), ??cnputc(), etc functions in sc and vt drivers.
We must still have siocngetc() and siocnputc() as globals because they
are directly referred to by i386-gdbstub.c :-(

Oked by: bde

Some staticized variables were still declared to be extern.

Fixed gratuitous ANSIisms.

Removed unused declarations.

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

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.

Move sysctl machdep.consdev to cons.c

Pass 3 of the great devsw changes
most devsw referenced functions are now static, as they are
in the same file as their devsw structure. I've also added DEVFS
support for nearly every device in the system, however
many of the devices have 'incorrect' names under DEVFS
because I couldn't quickly work out the correct naming conventions.
(but devfs won't be coming on line for a month or so anyhow so that doesn't
matter)

If you "OWN" a device which would normally have an entry in /dev
then search for the devfs_add_devsw() entries and munge to make them right..
check out similar devices to see what I might have done in them in you
can't see what's going on..
for a laugh compare conf.c conf.h defore and after... :)
I have not doen DEVFS entries for any DISKSLICE devices yet as that will be
a much more complicated job.. (pass 5 :)

pass 4 will be to make the devsw tables of type (cdevsw * )
rather than (cdevsw)
seems to work here..
complaints to the usual places.. :)

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.

cons.c:
Split off cdevsw initialization in cninit() into a new function
cninit_finish() that isn't called until all hardware device drivers
have been attached. The bdevsw entry of the driver for the physical
console needs to be hooked after the physical driver has been
attached in case the attachment modified the entry.

Rearrange cninit() to avoid changing cn_tab until the driver for the
physical console has been initialized, so that the previous driver
(if any) can be used for debugging.

Start removing half-baked lint support. bdevsw functions usually have
unused args but /*ARGSUSED*/ was used for only about 5% of them.

cons.h:
Declare cn_init_finish().

autoconf.c:
Call cn_init_finish().

Start adding prototypes. Functions with bogus linkage (extern where
static is probably should be static) are explicitly declared as extern
so that the can be found easily (extern in a non-header is usually
wrong).

All:
Continue cleaning up init stuff: init functions shall be static;
INITs should be at the start of files...

Undo the move of `#include "sc.h"' etc. to cons.h. It broke anything
that includes <machine/cons.h>.

Declare the console switch functions completely.

Move declarations of console functions to cons.h (they should be
config(8)ed).

Implement a simple hook (or hack?) to allow graphics device console
drivers to protect DDB from being invoked while the console is in
process-controlled (i.e., graphics) mode.

Implement the logic to use this hook from within pcvt. (I'm sure
Søren will do the syscons part RSN).

I've still got one occasion where the system stalled, but my attempts
to trigger the situation artificially resulted int the expected
behaviour. It's hard to track bugs without the console and DDB
available. :-/

Peter Dufaults comconsole changes.

Submitted by: Peter Dufault

The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.

Reviewed by: Rodney W. Grimes
Submitted by: John Dyson and David Greenman

Declare cnopen, cnclose, and other console routines.

Made all header files idempotent and moved incorrect common data from
headers into a related source file. (This is the only change to locore.s).
Also fixed pg() to be properly declared and use stdargs.

Removed all patch kit headers, sccsid and rcsid strings, put $Id$ in, some
minor cleanup. Added $Id$ to files that did not have any version info, etc

Initial import, 0.1 + pk 0.2.4-B1