A patch causing a healthy technical debate today on the Linux kernel mailing list would allow the kernel virtual terminal “VT” support to be enabled/disabled at boot time rather than being limited to the current CONFIG_VT build-time option.
Jocelyn Falempe of Red Hat proposed the 18 line patch to allow building the kernel with CONFIG_VT enabled but then at boot time be able to enable/disable it with either the vt.enable=1 or vt.enable=0 boot options.
Red Hat’s intent with this patch is to help with transitioning systems over to VT-less systems with ultimately using the likes of KMSCON as a user-space based console. With the upcoming Fedora 44 they are hoping to replace the kernel-based console with KMSCON.
It’s been a long-term goal of more than one decade to kill off the kernel VT console. With the patch today it would allow CONFIG_VT support to still be baked into the kernel but then at boot time for users that want to either enable/disable it depending upon your preference.
But today’s patch has seen some resistant expressed by Linux’s second-in-command Greg Kroah-Hartman. Greg expressed doubt over the merits of the patch and that distributiomn vendors alternatively could build kernels with/without the support and/or distributions should go all-in one way or another depending upon their VT preference. One suggestion being explored now is whether the VT support could be split-out as a Linux kernel module but that remains to be seen. Jocelyn Falempe’s justification of this current patch comes down to:
“It’s all about the transition. Talks about VT-less system started in 2012, but since then no major desktop Linux distribution have done it. I think that one of the reason, is that if you switch off VT, of course some users will complain, as it has a lot of implications. Telling them to go rebuild their kernel is not good. Telling them to run grubby to change the kernel command line until they find alternative for their use case is better. They can experiment and do the switch when they are ready.
Really it’s nothing more than that.
I don’t think a distribution will want to maintain VT and noVT for a long time.”
We’ll see where this work leads but in any event Fedora 44 is moving forward with their plans for the user-space KMSCON usage.
