Enabling framebuffer on a CentOS 7?

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ylluminate
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Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/20 23:16:07

I'm looking into how to enable /dev/fb0 on CentOS 7 for a virtual machine (ie, a Linode VPS) for headless TeamViewer support. It appears that this needs to be enabled via enabling a particular kernel module and Linode has recommended that this is just a matter of installing the correct CentOS kernel package, but has not further specific instructions.

What's the proper way to enable the frame buffer on CentOS 7?

ylluminate
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Re: Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/21 04:03:25

Doing a little more digging, I'm getting to the point where I'm wondering if I won't have to compile my own kernel to accomplish this. That's not preferable since it would benefit a lot more folks if a simple kernel package were installable and so I'm hoping for a bit simpler and cleaner option.

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TrevorH
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Re: Enabling framebuffer on a CentOS 7?

Post by TrevorH » 2017/09/21 13:17:03

Which option?
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
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ylluminate
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Re: Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/21 13:21:13

Meaning a precompiled option that can be `yum install`able vs compilation.

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TrevorH
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Re: Enabling framebuffer on a CentOS 7?

Post by TrevorH » 2017/09/21 13:22:52

I mean which option is it?
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

ylluminate
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Re: Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/21 13:42:45

It may be `vesafb` or `fbdev`. I've not found a clear answer for kernel 3.x and above:

https://en.wikipedia.org/wiki/Linux_framebuffer
• http://www.tldp.org/HOWTO/html_single/F ... fer-HOWTO/

This gave me some concern:
https://lkml.org/lkml/2015/9/24/253

-> https://en.wikipedia.org/wiki/Direct_Rendering_Manager

So it appears that fbdev is / has been or is being replaced, but the question is begged: what about those of us who need the framebuffer still for headless operation?

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TrevorH
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Re: Enabling framebuffer on a CentOS 7?

Post by TrevorH » 2017/09/21 13:58:30

It should already be set: grep CONFIG_FB_ /boot/config-3.10.0-693.2.2.el7.x86_64 for example.

I believe it gets disabled if you're using an incompatible video driver so perhaps look at that and also in dmesg
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

ylluminate
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Re: Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/21 14:08:04

Interesting, so since Linode VPS systems operate on a KVM host, are you aware of a potential match for the video driver issue? This is interesting:
https://www.phoronix.com/scan.php?page= ... &px=OTM0Nw

So we would need perhaps `qemu-kvm` or the Gallium3D Xen driver...? Hmmm...

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TrevorH
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Re: Enabling framebuffer on a CentOS 7?

Post by TrevorH » 2017/09/21 14:11:56

Linode often use their own kernels - what's the output of uname -a ?
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

ylluminate
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Re: Enabling framebuffer on a CentOS 7?

Post by ylluminate » 2017/09/21 14:17:20

Code: Select all

Linux hostname.domain.tld 4.9.36-x86_64-linode85 #1 SMP Thu Jul 6 15:31:23 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
They did mention using custom kernels and gave some instructions, etc. but I hate to screw with things too much since I prefer to work with stock kernels with them and the various guests with them. I might be able to request for them to build support into their provisioned kernels it if we can nail down precisely what to ask for.

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