# What causes this temporary grey screen initializing Linux?

## VinzC

Hi all.

IIRC ever since mode setting has been through the kernel I always see the screen go [light] grey while Linux initializes, then quickly resized, with a grey rectangle on top left of the screen (like shown on this picture though it's not my machine, just an example) until the frame buffer splash takes over from the initrd. I wonder what causes that "grey boot artefact" (which is how I'd call it without knowing for sure what it is). This happens whether or not mode setting is used.

It happens on both my Mint laptop and Gentoo home machine, both of which have an nVidia card. But it also happen in a virtual machine that boots a modern Linux kernel. Early boot splash is enabled on my home machine, i.e. I created an initrd with splashutils, which takes care of showing my lovely Danger Girl picture. However the screen turns grey between the boot menu and splash start.

Both my laptop and home machine start with extlinux using VESA module. Both show a boot menu: choice between Windows and Gentoo on my home machine and choice between two kernel version on my Mint laptop. There's no bootsplash on my laptop though.

So what makes the screen turn white/grey while loading Linux? Is it possible to keep it black all along? Is it due to some video memory residue left by the boot loader?

EDIT: Here are my Gentoo kernel arguments

```
... video=uvesafb:ywrap,1280x1024-32 splash=silent,theme:danger quiet console=tty1
```

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## Roman_Gruber

I just guess and assume its vbe.

Assuming my box, i have vbe in my grub.config which is loaded.

 *Quote:*   

> function load_video {
> 
>   insmod vbe
> 
>   insmod vga
> ...

 

And therefore after the initial bios thing which loads my grub2, grub2 loads vbe.

So I highly recommend to check your grub2 config for vbe and any other glx statement like set gfxmode=1920x1200x32

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## VinzC

 *tw04l124 wrote:*   

> So I highly recommend to check your grub2 config

   :Rolling Eyes: 

 *VinzC wrote:*   

> Both my laptop and home machine start with extlinux [...]

 

So there's no Grub config. That said, extlinux (syslinux) uses VESA only:

```
...

default vesamenu.c32

...
```

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## chithanh

My guess is that after extlinux boots the kernel, restore of the VGA text mode fails. Which causes the grey screen.

At least with grub2 it is possible to keep the VESA mode after loading the kernel with GRUB_GFXPAYLOAD_LINUX, and through CONFIG_X86_SYSFB and CONFIG_FB_SIMPLE let the kernel re-use that mode (instead of using e.g. uvesafb).

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## Faraclas

Interesting.  Are you using any binary graphics drivers?  I used to see this on boot using the nvidia driver.  Now my screnn just goes black for 10 seconds or so until the nvidia driver loads.

However, I DO see this when I shut down the system.  The screen goes crazy grey and I cant read any of the shutdown information.

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## VinzC

 *chithanh wrote:*   

> My guess is that after extlinux boots the kernel, restore of the VGA text mode fails. Which causes the grey screen.
> 
> At least with grub2 it is possible to keep the VESA mode after loading the kernel with GRUB_GFXPAYLOAD_LINUX, and through CONFIG_X86_SYSFB and CONFIG_FB_SIMPLE let the kernel re-use that mode (instead of using e.g. uvesafb).

 

Ah, that seems to make sense indeed. Is there anything I can do with my kernel config? I guess I'll need to file a bug by [ext|sys]linux maintainer to fix that if it turns out extlinux is responsible for that, right?

 *Faraclas wrote:*   

> Interesting.  Are you using any binary graphics drivers?  I used to see this on boot using the nvidia driver.  Now my screen just goes black for 10 seconds or so until the nvidia driver loads.
> 
> However, I DO see this when I shut down the system.  The screen goes crazy grey and I cant read any of the shutdown information.

 

Yes, I'm using nVidia blob. However I'm not sure it's loaded as early as when I see the grey screen. Shall I try including them into the initial ramdisk?

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## Faraclas

 *Quote:*   

> Shall I try including them into the initial ramdisk?

 

From http://wiki.gentoo.org/wiki/Uvesafb are you doing this?

```
General setup  --->

    [*] Initial RAM filesystem and RAM disk (initramfs/initrd) support

    (/usr/share/v86d/initramfs) Initramfs source file(s)
```

Note the /usr/share/v86d/initramfs

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## VinzC

 *Faraclas wrote:*   

> Note the /usr/share/v86d/initramfs

 

Just saw your message. I have to check that. I'd say "yes" but I might have used another path, like copy the initramfs somewhere and use that copy.

EDIT: Confirmed, that's what I did. A long time ago and I keep this configuration along with kernel upgrades. So what's next?

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## Faraclas

This is the grub command line that I am using, maybe double check yours?

```
GRUB_CMDLINE_LINUX="rootfstype=ext4 video=uvesafb:1024x768-60,mtrr:3,ywrap acpi_sleep=nonvs"
```

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## VinzC

 *Faraclas wrote:*   

> This is the grub command line that I am using, maybe double check yours?
> 
> ```
> GRUB_CMDLINE_LINUX="rootfstype=ext4 video=uvesafb:1024x768-60,mtrr:3,ywrap acpi_sleep=nonvs"
> ```
> ...

 

Mine is on my first post, unchanged since. You can see it is quite similar to yours. I remember I had to use the default for mtrr. Is the acpi_sleep required?

EDIT: I notice you have 1024x768-60. Shouldn't it be 1024x768@60?

----------

