[SOLVED] How to replace the tty in linux with some application?

me_231231 · 2023-08-16 15:29:44

Linux has extensive tty layer that will run on everything, however I want something more modern, at least with font support.
In my head solutions looks something like this. Disable tty layer so that /dev/tty devices dont get created and run some application instead.

For example can I replace whole tty layer with something akin tp fbterm or some other application that uses framebuffer for rendering?
Would I still be able to startx if I turn off tty layer?
Does tty layers has any alternatives?
Can I customize tty layer to render fonts and colors (no I do not want to start X since some window managers get freeze and I need something extrnal to X to make the system "unfreeze" without reboot)?

Alternatively, can I somehow make tty use some framebuffer program for user login? Because after login I guess I can start fbterm with a script.

Last edited by me_231231 (2023-08-18 23:03:57)

Trilby · 2023-08-16 15:52:45

Your use of the word "layer" is a misleading reification. There is no such "layer".

You most certainly can replace (a)getty with alternatives including fbterm / yaft and the like. There are instructions for doing so in the wiki.

me_231231 · 2023-08-16 16:21:22

Trilby wrote:

Your use of the word "layer" is a misleading reification. There is no such "layer".
You most certainly can replace (a)getty with alternatives including fbterm / yaft and the like. There are instructions for doing so in the wiki.

So I can replce tty login with something else. Thing is X can break especially on systems with nvidia. Can I replace login into virtual terminal on /dev/tty{0-6} with gui framebuffer login?

Trilby · 2023-08-16 16:39:53

me_231231 wrote:

Can I replace login into virtual terminal on /dev/tty{0-6} with gui framebuffer login?

Yes.

Whether or not you can launch X from that very same tty or not I'm not entirely sure - especially with NVIDIA. I've (thankfully) never used NVIDIA; it has lots of it's own quirks.

But you could, for example, put a framebuffer loging on all but one virtual terminal / console and have X run on the other. There are even ways to run X on a console without ever login in to any tty there - though I wouldn't really advise this.

me_231231 · 2023-08-16 18:37:02

Trilby wrote:

Your use of the word "layer" is a misleading reification. There is no such "layer".
You most certainly can replace (a)getty with alternatives including fbterm / yaft and the like. There are instructions for doing so in the wiki.

I am maybe dumb, but can you provide me links to the wiki where it says how to change getty for fbterm, cannot find it .
fbterm or getty pages dont say anything about it.

seth · 2023-08-16 19:39:14

Principally explained for https://wiki.archlinux.org/title/KMSCON
Not sure for https://wiki.archlinux.org/title/Fbterm … nvironment - you might have to derivce your own service file if the package doesn't provide one.

Edit: make sure to have some live distro around to fix things offline if you screw this up!

Last edited by seth (2023-08-16 19:39:56)

me_231231 · 2023-08-16 20:30:00

seth wrote:

Principally explained for https://wiki.archlinux.org/title/KMSCON
Not sure for https://wiki.archlinux.org/title/Fbterm … nvironment - you might have to derivce your own service file if the package doesn't provide one.
Edit: make sure to have some live distro around to fix things offline if you screw this up!

I have it ready from fiasco in my last question you answered, don't worry and thank you.

me_231231 · 2023-08-17 19:03:03

seth wrote:

Principally explained for https://wiki.archlinux.org/title/KMSCON
Not sure for https://wiki.archlinux.org/title/Fbterm … nvironment - you might have to derivce your own service file if the package doesn't provide one.
Edit: make sure to have some live distro around to fix things offline if you screw this up!

I am sorry but it appears to me that fbterm does not have any login abilities and I am lost as how to start it with default arch linux agetty. When I pass "fbterm" instead of $TERM it only sets the $TERM environment variable to fbterm and does not start fbterm upon login, but default linux shell with only 8 colors.
Also there seems to an option for --login-program, does that mean I can use a custom framebuffer program for login there?

Last edited by me_231231 (2023-08-17 19:03:50)

seth · 2023-08-17 20:07:27

I've no idea whether fbterm can serve as a full console/agetty replacement but if it ca, you want to replace getty@tty1.service, not set some $TERM (what you generally should refrain from anyway)

Trilby · 2023-08-17 20:11:35

fbterm itself does not provide a login, nor does yaft (AFAIK). But you could autologin and run one of these programs. Or you could start them via a framebuffer login program (I know there are some, but I don't recall).

Though I believe KMSCON would kill two birds with one stone and seems the better approach to me anyways.

me_231231 · 2023-08-17 20:27:04

Trilby wrote:

fbterm itself does not provide a login, nor does yaft (AFAIK). But you could autologin and run one of these programs. Or you could start them via a framebuffer login program (I know there are some, but I don't recall).
Though I believe KMSCON would kill two birds with one stone and seems the better approach to me anyways.

KMSCON does not seem to support ttf fonts, can I start fbterm from withing KMSCON console after I login into it?

me_231231 · 2023-08-17 20:30:17

Also KMSCON appears to be dead
Last commit in 2014
Cannot find anything online on alternatives either.

Last edited by me_231231 (2023-08-17 20:43:33)

seth · 2023-08-17 20:55:13

Don't bump. Edit your previous post if nobody has replied.

The wiki wrote:

Alternatively, install kmscon-patched-gitAUR. The patched version, along with its patched dependency (libtsm-patched-gitAUR), includes fixes and improvements (like 24-bit color support) that the canonical version (which has not been updated since 2014) does not.

Trilby wrote:

But you could autologin and run one of these programs

man agetty, " --login-program"

Trilby · 2023-08-17 21:10:37

me_231231 wrote:

KMSCON does not seem to support ttf fonts

seem? It certainly does. It uses pango for font loading/layout and the wiki page even explicitly recommends having specific ttf fonts installed if one needs CJK support.

me_231231 · 2023-08-18 18:21:02

I have been able to install and run KMSCON with 256 colors, however I am unable to startx from within KMSCON. It says "Cannot open virtual console 1".
The wiki suggests I enable hwaccel option (this also requires drm option), but it does not help. Disabling them does not help either.

seth · 2023-08-18 18:23:29

This is for switching forth and back, post your xinitrc and xserverrc and but see https://wiki.archlinux.org/title/Xinit#xserverrc first

me_231231 · 2023-08-18 18:39:59

seth wrote:

This is for switching forth and back, post your xinitrc and xserverrc and but see https://wiki.archlinux.org/title/Xinit#xserverrc first

Here is my xserverrc:

#!/bin/sh
exec /usr/bin/X -nolisten tcp "$@" vt$XDG_VTNR

Here is my ~/.xinitrc:

#!/bin/sh

userresources=$HOME/.Xresources
usermodmap=$HOME/.Xmodmap
sysresources=/etc/X11/xinit/.Xresources
sysmodmap=/etc/X11/xinit/.Xmodmap

# merge in defaults and keymaps

if [ -f $sysresources ]; then
    xrdb -merge $sysresources
fi

if [ -f $sysmodmap ]; then
    xmodmap $sysmodmap
fi

if [ -f "$userresources" ]; then
    xrdb -merge "$userresources"
fi

if [ -f "$usermodmap" ]; then
    xmodmap "$usermodmap"
fi

if [ -d /etc/X11/xinit/xinitrc.d ] ; then
 for f in /etc/X11/xinit/xinitrc.d/?*.sh ; do
  [ -x "$f" ] && . "$f"
 done
 unset f
fi

xrandr --auto
exec startxfce4

Also it seems that is not supported due to: https://github.com/dvdhrm/kmscon/issues/65
Do I need to modify the current configuration to make X start on a different vt, like vt7?

seth · 2023-08-18 18:43:16

Do I need to modify the current configuration to make X start on a different vt, like vt7?

What would be the worst possible outcome if you just tried?

me_231231 · 2023-08-18 18:53:28

seth wrote:

Do I need to modify the current configuration to make X start on a different vt, like vt7?
What would be the worst possible outcome if you just tried?

This post says things will break in X: https://unix.stackexchange.com/question … arch-linux
I don't wnat that to happen ofc. So I am unsure what to do so things don't break.

seth · 2023-08-18 18:56:44

You mean the computer might explode into your face and kill you when this happens?

Read the xserverrc wiki entry I linked. It explains why to run X11 on the active console and provides an alternative to that as well.

me_231231 · 2023-08-18 19:14:48

seth wrote:

You mean the computer might explode into your face and kill you when this happens?
Read the xserverrc wiki entry I linked. It explains why to run X11 on the active console and provides an alternative to that as well.

Sorry for being extremely dense, but I do not get how to do it. When I did "chvt 7 && export XDG_VTNR=7 && sleep 1 && sudo chown dk:tty /dev/tty7 && startx -- vt7 &" it has thrown me into X without mouse or keyboard or ability to switch vts.
The wiki mentions /usr/lib/systemd/systemd-multi-seat-x but I dont have such file on my system
Both pacman and paru don't have such package for install either.

seth · 2023-08-18 19:25:40

The "simple" solution here is going to be to run X11 as root (not "sudo" it but use the xorg wrapper)
https://wiki.archlinux.org/title/Xorg#Xorg_as_Root (yes, I know about the warning)

Sorry, that thing apparently got dropped ages ago and nobody fixed the wiki.
https://cgit.freedesktop.org/systemd/sy … 50cd99031e

me_231231 · 2023-08-18 19:50:03

seth wrote:

The "simple" solution here is going to be to run X11 as root (not "sudo" it but use the xorg wrapper)
https://wiki.archlinux.org/title/Xorg#Xorg_as_Root (yes, I know about the warning)
Sorry, that thing apparently got dropped ages ago and nobody fixed the wiki.
https://cgit.freedesktop.org/systemd/sy … 50cd99031e

Hmmmmm, I dont want to run Xorg as root, would it be a viable solution to write a script that would make user login on tty? I know I can manually start agetty there with autologin, then there the profile script would execute startx and then we do chvt to over there?
Or I am not allowed to do sudo agetty on a tty7?

Last edited by me_231231 (2023-08-18 19:55:21)

Trilby · 2023-08-18 20:17:45

Ah, wut? If you're okay with autologin, none of this is relevant. Just set up autologin and autostart of X as outlined in the wiki on whichever tty you want X running on.

Or in other words:

Me from 20 posts ago! wrote:

... put a framebuffer loging on all but one virtual terminal / console and have X run on the other. There are even ways to run X on a console without ever login in to any tty there - though I wouldn't really advise this.

Last edited by Trilby (2023-08-18 20:19:04)

me_231231 · 2023-08-18 20:26:32

Trilby wrote:

Ah, wut? If you're okay with autologin, none of this is relevant. Just set up autologin and autostart of X as outlined in the wiki on whichever tty you want X running on.
Or in other words:
Me from 20 posts ago! wrote:
... put a framebuffer loging on all but one virtual terminal / console and have X run on the other. There are even ways to run X on a console without ever login in to any tty there - though I wouldn't really advise this.

I wanted to not do autologin and start X on tty7, but it seems not possible without running X as root as I mentioned above.
The reason I even considered autologin is so that after the user did login and wants to startx it would go to tt7, but I am unable to do so, wiki points to some utility that is not there anymore.

Last edited by me_231231 (2023-08-18 20:27:01)

Arch Linux

#1 2023-08-16 15:29:44

[SOLVED] How to replace the tty in linux with some application?

#2 2023-08-16 15:52:45

Re: [SOLVED] How to replace the tty in linux with some application?

#3 2023-08-16 16:21:22

Re: [SOLVED] How to replace the tty in linux with some application?

#4 2023-08-16 16:39:53

Re: [SOLVED] How to replace the tty in linux with some application?

#5 2023-08-16 18:37:02

Re: [SOLVED] How to replace the tty in linux with some application?

#6 2023-08-16 19:39:14

Re: [SOLVED] How to replace the tty in linux with some application?

#7 2023-08-16 20:30:00

Re: [SOLVED] How to replace the tty in linux with some application?

#8 2023-08-17 19:03:03

Re: [SOLVED] How to replace the tty in linux with some application?

#9 2023-08-17 20:07:27

Re: [SOLVED] How to replace the tty in linux with some application?

#10 2023-08-17 20:11:35

Re: [SOLVED] How to replace the tty in linux with some application?

#11 2023-08-17 20:27:04

Re: [SOLVED] How to replace the tty in linux with some application?

#12 2023-08-17 20:30:17

Re: [SOLVED] How to replace the tty in linux with some application?

#13 2023-08-17 20:55:13

Re: [SOLVED] How to replace the tty in linux with some application?

#14 2023-08-17 21:10:37

Re: [SOLVED] How to replace the tty in linux with some application?

#15 2023-08-18 18:21:02

Re: [SOLVED] How to replace the tty in linux with some application?

#16 2023-08-18 18:23:29

Re: [SOLVED] How to replace the tty in linux with some application?

#17 2023-08-18 18:39:59

Re: [SOLVED] How to replace the tty in linux with some application?

#18 2023-08-18 18:43:16

Re: [SOLVED] How to replace the tty in linux with some application?

#19 2023-08-18 18:53:28

Re: [SOLVED] How to replace the tty in linux with some application?

#20 2023-08-18 18:56:44

Re: [SOLVED] How to replace the tty in linux with some application?

#21 2023-08-18 19:14:48

Re: [SOLVED] How to replace the tty in linux with some application?

#22 2023-08-18 19:25:40

Re: [SOLVED] How to replace the tty in linux with some application?

#23 2023-08-18 19:50:03

Re: [SOLVED] How to replace the tty in linux with some application?

#24 2023-08-18 20:17:45

Re: [SOLVED] How to replace the tty in linux with some application?

#25 2023-08-18 20:26:32

Re: [SOLVED] How to replace the tty in linux with some application?

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