Switch the default terminal emulation style to xterm for most platforms.

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@

1 files changed, 15 insertions, 0 deletions

diff --git a/UPDATING b/UPDATING
index 170248c..85ad0d4 100644
--- a/UPDATING
+++ b/UPDATING
@@ -22,6 +22,21 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 9.x IS SLOW:
 	machines to maximize performance.  (To disable malloc debugging, run
 	ln -s aj /etc/malloc.conf.)
 
+20091113:
+	The default terminal emulation for syscons(4) has been changed
+	from cons25 to xterm on all platforms except i386 and pc98.
+	This means that the /etc/ttys file needs to be updated to ensure
+	correct operation of applications on the console.
+
+	The terminal emulation style can be toggled per window by using
+	vidcontrol(1)'s -T flag.  The TEKEN_XTERM and TEKEN_CONS25
+	kernel configuration options can be used to change the
+	compile-time default.
+
+	To prevent graphical artifacts, make sure the TERM environment
+	variable is set to match the terminal emulation that is being
+	performed by syscons(4).
+
 20091109:
 	The layout of the structure ieee80211req_scan_result has changed.
 	Applications that require wireless scan results (e.g. ifconfig(8))