VirtualBox 6.0 Guest running Slackware 14.2 no text console display
 

I'm not having much success getting a VirtualBox 6.0.16 Windows 7 host to display the text console for a Slackware 14.2 64-bit Guest after the "vboxvideo" module is loaded.

I figured I would ask the question here and also share my work around.

I'm not running the latest major VirtualBox version 6.1 because I've found that the latest version is often broken. I just recently moved from the last 5.x version to 6.0 and thought it was working well until I ran into the text console problem.

The VirtualBox Guest Additions have undergone a major change from 5.x to 6.0. Among other things, the "vboxvideo" driver is now loaded during kernel initialization to support the frame buffer.

The problem is that the frame buffer support in "vboxvideo" seems to be broken. The text console display is only updated sometimes when you switch between screens, but never when you are actually viewing the text console and typing.

Most of the time that isn't important, since a terminal emulator application can be used. It is a big problem when trying to boot into single user mode or multi-user text mode.

My work around was to prevent the "vboxvideo" module from being loaded by the kernel when the framebuffer device is detected.

I created a file named "/etc/modprobe.d/vboxvideo.conf" containing the line to blacklist vboxvideo.

There might be a better way to do that, but it works.

Next, I changed the initialization for run level 3 to stop VirtualBox services rather than start them.

I renamed the following files in "/etc/rc.d/rc3.d".

Renaming them to begin with "K" makes them stop the services instead of starting the services.

The drawback to this workaround is that the VirtualBox shared folders and shared clipboard are not available except when using run level 4.

I've found that it's better to work around problems rather than switching versions of VirtualBox because that usually just trades one set of problems for a different set. When I have time, I may try some of the 6.1 versions to see how well they work for me.

If anyone knows a way to get the text console to work properly or a better work around, please post it.

Also, if you are running some version of VirtualBox 6.1, I'm interested in hearing how well it works for you and how you are using it. I mostly run a Windows 7 64-bit host OS with a Windows XP 32-bit or Windows 7 64-bit guest. I sometimes run a Slackware Linux 64-bit guest.

I'm on Slackware64-Current host, and VB-6.1.2 works fine for Mint and Win10 VMs.

You're using a Windows host so I'm probably no help, but I'm using Slackware 14.2 as my host and using VBox 6.1.2. Working fine.

assuming that you have all pieces installed (extensions and guest), it does not matter for your client if versions for client and host are similar.

VB requires gui for clipboard to work of course.

I have Slackware (not -14.2 but -current) as host and as client installed and for client vboxvideo works. Also if you run default Slackware kernel, VMSVGA may not be enabled (I a not sure about this as I don't run default kernel)

You can play with vboxvideo drivers:
switching from new
VMSVGA to old VboxSVGA
but this is tricky:
VB Manager will revert automatically (for linux) from VboxSVGA to VMSVGA.


There is preatty easy way to avoid this and keep VboxSVGA (and add up to 256MB video RAM - not available from defaut settings panel) for linux.

So try switching to VboxSVGA.

Two things: First, I'm also on Slackware64-Current, Given you're on a windoze host, you may get more informed replies on a windoze forum.

Second thing, as reboots are pretty cheap, I would at least try disabling framebuffer andjust running on vboxvideo. Works here.

Actually, that information is helpful. I dual boot Slackware 14.2 and eventually will want to upgrade both Windoze and Slackware to the 6.1 branch.

Can I disable framebuffer using a kernel parameter, or do I need to rebuild the kernel? I know how to rebuild the kernel, so that won't be a problem. I tried changing boot parameters for the text console mode and it had no effect on the framebuffer driver loading. I am using the lilo bootloader, but I can also use grub2 if that will make things easier.

Here is my /etc/lilo.conf
I tried using "vga = normal" and the vboxvideo driver still loaded, making the text console display inoperative.

I think that the Plug-and-Play hardware detection is what loads the vboxvideo module based on detecting the VirtualBox framebuffer device. I put the relevant kernel log output below.

Thanks for the replies.

I have a Linux host, so the problem is, of course different.

I ignored vga in the lilo section, as once your video driver loads as the kernel boots, all that is forgotten about. I don't have xf86-video-vesa or xf86-video-fb installed, so nothing In X has that option. 'cmd' prompts in windows should be enough to install slackware. AFAIK, vboxvideo simply passes back the video to windows, unless you know otherwise.

If you leave out the 'vga=791' which isn't what you want unless you have a 4:3 monitor, you can blacklist the framebuffer module in /etc/modprobe.d/blacklist, and that should stop it loading temporarily, unless it's in the initrd. It saves the inconvenience of a kernel rebuild.

It also appears you are using vboxdrmfb, not vboxvideo. Framebuffer was originally about console hi-res without vga cards. But with cards like the S3 (1996) & friends, it's days appeared numbered. Those were the days when you had to cobble up your own modeline, allowing for things like flyback time in Analogue monitors. Have you had a look at improving things in the VB settings for your guest?

[ 35.422651] fb: switching to vboxdrmfb from VESA VGA
[ 35.422685] Console: switching to colour dummy device 80x25
[ 35.423903] fbcon: vboxdrmfb (fb0) is primary device

I don't know why you have vboxdrmfb. In my case this is vboxvideodrmfb
also what is lpsci -k showing?
so the problem may be in the kernel

your lilo is o.k.
I have
vga = 791
in lilo enabbled too. It just shows nicely number of processors and obviously it is more readable.

xf86-video-fb is not even available under -current (at least I don't see it)

in the kernel I have
DRM_VBOXVIDEO
DRM_VMWGFX
DRM_VMWGFX_FBCON

simple workaround
 

I had the same issue.
It seems that is related to guest additions version xxx.22 .
But I found this workaround:
Configure Graphic board in Virtual Box machine settings as VMSVGA instead of VBoxVGA or VBoxxVGA
I hope that with the future guest additions or maybe different kernel this problem will be solved.