Bug 276206 - Setting kern.vty="sc" will hang the loader boot process, but vt(4) says we can do that
Summary: Setting kern.vty="sc" will hang the loader boot process, but vt(4) says we ca...
Status: New
Alias: None
Product: Documentation
Classification: Unclassified
Component: Manual Pages (show other bugs)
Version: Latest
Hardware: amd64 Any
: --- Affects Only Me
Assignee: freebsd-bugs (Nobody)
URL:
Keywords: vt
Depends on:
Blocks:
 
Reported: 2024-01-08 20:53 UTC by hym2209268914
Modified: 2024-01-10 00:10 UTC (History)
4 users (show)

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Description hym2209268914 2024-01-08 20:53:27 UTC 
From manpage vt(4), LOADER TUNABLES:

    kern.vty
	       Set this	value to `vt' or `sc' to choose	a specific system con-
	       sole,  overriding the default.  The GENERIC kernel uses vt when
	       this value is not set.

on my GENERIC kernel shipped with 14.0-RELEASE, adding a line to /boot/loader.conf 'kern.vty="sc"' will hang the loader while loading kernel and trying to boot.
Comment 1 Daniel O'Connor 2024-01-09 00:29:01 UTC 
Can you upload a photo of where it hangs?
Comment 2 hym2209268914 2024-01-09 12:11:57 UTC 
It hangs right after the loader loads the kernel, and prints the EFI framebuffer information as usual, where the kernel should clear the screen and print dmesg in a couple of seconds. There are no error message.
Comment 3 Maxim Konovalov freebsd_committer freebsd_triage 2024-01-09 16:21:23 UTC 
Hi,

Probably not a solution but rather a workaround: give a try to "hw.vga.textmode=1"

Maxim
Comment 4 Kyle Evans freebsd_committer freebsd_triage 2024-01-09 18:07:13 UTC 
syscons notably doesn't know at all how to find the efi framebuffer, so if you're booting via efi this is expected and the machine likely isn't actually hung (but just not drawing to the screen).
Comment 5 hym2209268914 2024-01-10 00:09:34 UTC 
Maybe we should add a note to vt(4) pointing out which tunables are not available in UEFI booted systems?
Comment 6 hym2209268914 2024-01-10 00:10:29 UTC 
(In reply to Maxim Konovalov from comment #3)
hw.vga.textmode=1 does not seem to work in uefi either.