And simplify this a little by flattening the directory structure. Approved by: re (gjb), will (mentor) Differential Revision: https://reviews.freebsd.org/D16955
Differential Revision: https://reviews.freebsd.org/D15169
Discussed on: -arch@ (no objections) MFC after: 1 week Sponsored by: The FreeBSD Foundation
allows us to change the uart(4) driver to not hardcode specific line settings for the serial console. A terminal type of 3wire makes sure the console still works when no DCD signal is present, which preserves behviour. When it is known that the terminal server (or DCE in general) provides DCD, a terminal type/class of std can be used. This has the effect of being logged out when one disconnects from the console -- improving security overall. Likewise, when uart(4) does not fixate the baudrate, one can change the terminal type/class to set a specific baudrate. An operator can use this to change the console speed mid-flight, without needing a reboot. Of course it helps in this respect if and when the firmware can be configured from the OS. The above mentioned capabilities depend on uart(4) being changed, which is to happen next.
Pseudo-terminals are no longer listed in this file, since the utmpx implementation doesn't depend on ttyslot().
When we had utmp(5), we had to list all the psuedo-terminals in ttys(5) to make ttyslot(3) function properly. Now that pututxline(3) deals with slot allocation internally (not based on TTY names), we don't need to list all the TTYs on the system in ttys(5) to make user accounting work properly. This patch removes all the entries from the /etc/ttys files, but also the pts(4) entries that were appended implicitly, which was added in r154838.
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@
vt220 will not work better. Even though it probably will remove warnings about unknown terminal types, a cons25 emulator is not compatible with vt220 at all.
Even though I increased the amount of pts(4) entries in /etc/ttys some time ago, I didn't realize back then those entries shouldn't have been there in the first place. I just looked at the getttyent() source code and it turns out when you call setttyent(), it walks through /dev/pts and looks for the device with the highest number. After you receive EOF's from getttyent(), it makes up entries for pts(4) devices. This means that adding entries for pts(4) is somewhat harmful, because if you now traverse the list, you get redundant entries, so just remove them.
As discussed with Robert Watson on the src-committers list, it is safer to keep at least some pty(4) entries in /etc/ttys, for applications that roll their own PTY allocation routine and only search for BSD-style PTY's. This means we've now just toggled the amount of entries for pts(4) and pty(4). Requested by: rwatson