Right now syscons(4) uses a cons25-style terminal emulator. The
disadvantages of that are:
- Little compatibility with embedded devices with serial interfaces.
- Bad bandwidth efficiency, mainly because of the lack of scrolling
regions.
- A very hard transition path to support for modern character sets like
UTF-8.
Our terminal emulation library, libteken, has been supporting
xterm-style terminal emulation for months, so flip the switch and make
everyone use an xterm-style console driver.
I still have to enable this on i386. Right now pc98 and i386 share the
same /etc/ttys file. I'm not going to switch pc98, because it uses its
own Kanji-capable cons25 emulator.
IMPORTANT: What to do if things go wrong (i.e. graphical artifacts):
- Run the application inside script(1), try to reduce the problem and
send me the log file.
- In the mean time, you can run `vidcontrol -T cons25' and `export
TERM=cons25' so you can run applications the same way you did before.
You can also build your kernel with `options TEKEN_CONS25' to make all
virtual terminals use the cons25 emulator by default.
Discussed on: current@
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.
- VBE 3.0 says palette format resets to 6-bit mode when video mode changes.
We simply set 8-bit mode when we switch modes if the adapter supports it.
- VBE 3.0 also says if the mode is not VGA compatible, we must use VBE
function to save/restore palette. Otherwise, VGA function may be used.
Thus, reinstate the save/load palette functions only for non-VGA compatible
modes regardless of its palette format.
- Let vesa(4) set VESA modes even if vga(4) claims to support it.
- Reset default palette if VESA pixel mode is set initially.
- Fix more style nits.
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)
It is quite inconvenient that if an application for xterm uses 256 color
mode, text suddenly starts to blink (because of ;5; in the middle).
We'd better just implement 256 color mode and add a conversion routine
from 256 to 8 color mode, which doesn't seem to be too bad in practice.
Remapping colors is done quite simple. If one of the channels is most
actively represented, primary colors are used. If two channels are most
actively represented, secondary colors are used. If all three channels
are equal (gray), it picks between black and white.
Reported by: Paul B. Mahol <onemda gmail com>
This code seems to do exactly the same as ttydisc_rint_simple() does
nowadays. Just remove it.
Obtained from: //depot/user/ed/newcons/sys/dev/syscons/syscons.c
For some vague reason, it may be possible that scp->cursor_pos exceeds
scp->ysize * scp->xsize. This means that teken_set_cursor() may get
called with an invalid position. Just ignore the old cursor position in
this case.
Reported by: Paul B. Mahol <onemda gmail com>
MFC after: 1 month
"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.
where we figure out the hostname length under the lock, malloc the buffer
with the lock dropped, then recheck the length under the lock and loop again
if the buffer is now too small.
Tested by: Norbert Koch nkoch demig de
MFC after: 3 days
- Add vesa kernel options for amd64.
- Connect libvgl library and splash kernel modules to amd64 build.
- Connect manual page dpms(4) to amd64 build.
- Remove old vesa/dpms files.
Submitted by: paradox <ddkprog yahoo com> [1], swell k at gmail.com
(with some minor tweaks)
Right now libteken processes TF_REVERSE internally and returns the
toggled colors to the console driver. This isn't entirely correct. This
means that the bold flag is always processed by the foreground color,
while reversing should be done after the foreground color has been set
to a brighter version by the bold flag.
This is no problem with the syscons driver, because with VGA it only
supports 16 foreground and 8 background colors. My WIP console driver
reconfigures the graphics hardware to disable the blink functionality
and uses 16 foreground and 16 background colors. This means that this
driver will handle the TF_REVERSE flag a little different from what
syscons does right now.
I initially committed libteken to sys/dev/syscons/teken, but now that
I'm working on a console driver myself, I noticed this was not a good
decision. Move it to sys/teken to make it easier for other drivers to
use a terminal emulator.
Also list teken.c in sys/conf/files, instead of listing it in all the
files.arch files separately.
Characters between 0x07 and 0x0d are now also mapped, which means we can
display almost 256 different characters. Also remap certain types of
dashes and quotes, which means we can finally read our manual pages
without red question marks in them.
Submitted by: Christoph Mallon
Add a small Unicode-to-CP437 remapping table to at least demonstrate
that the terminal emulator is perfectly capable of handling UTF-8. This
will of course break if the user loads a different font map, but it at
least allows people to give it a try.
I can now see the box drawing in dialog(1) and the arrows in mutt(1)
correctly.
Because we only support a single argument to tf_param, use 16 bits for
the pitch and 16 bits for the duration. While there, make the argument
unsigned. There isn't a single param call that needs a signed integer.
Submitted by: danfe (modified)
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex. Jails may
have their own host information, or they may inherit it from the
parent/system. The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL. The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.
The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.
Approved by: bz (mentor)
I don't want people to override the mutex when allocating a TTY. It has
to be there, to keep drivers like syscons happy. So I'm creating a
tty_alloc_mutex() which can be used in those cases. tty_alloc_mutex()
should eventually be removed.
The advantage of this approach, is that we can just remove a function,
without breaking the regular API in the future.
Apart from the 16 virtual terminals, Syscons allocates two device nodes
that should not really be TTYs, even though they are. One of them is
consolectl. In RELENG_7 and before, these device nodes are used in
single user mode. After I simplified input path, we only use this device
node to call ioctl() on (moused, Xorg, vidcontrol).
When you call ioctl() on consolectl, it will behave the same as being
called on the first window.
It seems I didn't fix this issue before committing teken to the tree. My
initial idea was to somehow add an error mechanism to instruct the video
driver author to increase T_NUMCOL when using very big terminals. It
turns out we have platforms where we have gigantic consoles on systems
like the Apple PowerMac G5, which means we crash there right now.
Just ignore tabstops placed beyond column 160. Just force tabs to be
placed on each 8 columns.
Reported by: nwhitehorn
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)
We should just leave the underlying TTY objects alone when scrolling
around in KDB. It should be handled by Syscons exclusively.
Reported by: pluknet gmail com
Some time ago I tried adding Unicode rendering to the teken demo
application, but I didn't get it working. It seems I forgot to call
setlocale(). Polish this code and make sure it doesn't get lost.
Also a small fix for my previous commit: all Unicode characters in
teken_boxdrawing are below 0x10000, so store them as 16-bit values.
Even though VT100-like devices can display non-ASCII characters, they do
not use an 8-bit character set. Special escape sequences allow the VT100
to switch character maps. The special graphics character set stores the
box drawing characters, starting at 0x60, ending at 0x7e. This means
we now pass the character map tests in vttest, even the save/restore
cursor test, combined with character maps. dialog(1) also works a lot
better now.
This commit also includes some other minor fixes:
- Default to 24 lines in teken_demo when using xterm emulation.
- Make white foreground and background work in teken_demo.
Cons25 doesn't seem to use a straight 1:1 mapping to the ANSI colors,
but uses the same color numbers as at least used by syscons on i386. I
suspect if you change the definitions on a different architecture,
things may break? Not sure.
Add a small array to convert syscons-style color codes to ANSI
equivalents, which are used by libteken internally. I didn't notice this
bug, because I only tested my code with black, white and green, all of
them shared the same numbers.
It turns out I forgot to implement two escape sequences that allows the
user to change the default foreground and background colors. I thought
they were implemented by syscons itself, but vidcontrol just generates
some escape sequences, which get interpreted by the terminal emulator.
Reported by: mgp (forums)
The teken library already supports UTF-8 handling and xterm emulation,
but we have reasons to disable this right now. Because we should make it
easy and interesting for people to experiment with these features, allow
them to be set in kernel configuration files.
Before this commit we had a flag called `TEKEN_CONS25' to enable
cons25-style emulation. I'm calling it the opposite now, `TEKEN_XTERM',
because we want to enable it in kernel configuration files explicitly.
Requested by: kib
- Implement NP (ASCII 12, Form Feed). When used with cons25, it should
clear the screen and place the cursor at the top of the screen. When
used with xterm, it should just simulate a newline.
- When we want to use xterm emulation, make teken_demo set TERM to
xterm.
Spotted by: Paul B. Mahol <onemda@gmail.com>
Because we now have cons25-style linewrapping, we must also use cons25-
style reverse linewrapping. This means that a ^H on column 0 will move
the cursor one line up.
Also fix a small regression: if the user invokes a RIS (Reset to Initial
State), we must show the cursor again.
Spotted by: Paul B. Mahol <onemda gmail com>
With cons25, there are printable characters below 0x1B. This is not the
case with ASCII, UTF-8, etc. but in this case we just have to.
Also don't set LC_CTYPE to UTF-8 when libteken is compiled without UTF-8
in the demo-application.
It turns out I was looking too much at mimicing xterm, that I didn't
take the differences of cons25 into account. There are some differences
between xterm and cons25 that are important. Create a new #define called
TEKEN_CONS25 that can be toggled to switch between cons25 and xterm
mode.
- Don't forget to redraw the cursor after processing a forward/backward
tabulation.
- Implement cons25-style (WYSE?) autowrapping. This form of autowrapping
isn't that nice. It wraps the cursor when printing something on column
80. xterm wraps when printing the first character that doesn't fit.
- In cons25, a \t shouldn't overwrite previous contents, while xterm
does.
Reported by: Garrett Cooper <yanefbsd gmail com>
The cursor is only inside the scrolling region when we are in origin
mode. In that case, it should use originreg instead of scrollreg. It is
completely valid to place the cursor outside the scrolling region.
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)
On RELENG_6 (and probably RELENG_7) we see our syscons windows and
pseudo-terminals have the following buffer sizes:
| LINE RAW CAN OUT IHIWT ILOWT OHWT LWT COL STATE SESS PGID DISC
| ttyv0 0 0 0 7680 6720 2052 256 7 OCcl 1146 1146 term
| ttyp0 0 0 0 7680 6720 1296 256 0 OCc 82033 82033 term
These buffer sizes make no sense, because we often have much more output
than input, but I guess having higher input buffer sizes improves
guarantees of the system.
On MPSAFE TTY I just sent both the input and output buffer sizes to 7
KB, which is pretty big on a standard FreeBSD install with 8 syscons
windows and some PTY's. Reduce the baud rate to 9600 baud, which means
we now have the following buffer sizes:
| LINE INQ CAN LIN LOW OUTQ USE LOW COL SESS PGID STATE
| ttyv0 1920 0 0 192 1984 0 199 7 2401 2401 Oil
| pts/0 1920 0 0 192 1984 0 199 5631 1305 2526 Oi
This is a lot smaller, but for pseudo-devices this should be good
enough. You need to do a lot of punching to fill up a 7.5 KB input
buffer. If it turns out things don't work out this way, we'll just
switch to 19200 baud.
