# Kernel Mode Setting and Ati

## Judge584

Hi,

I'm running ~amd64 gentoo with kms enabled and this is working good.

However, between the grub boot screen and the kde login screen, my monitor is in standby mode so it is impossible to see boot messages.

How to prevent my monitor going in standby mode between grub and kde? I cannot figure this out.

Best regards,

J.

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## audiodef

Post the output of lspci -n and I'll see if I can help you with that. You probably need a framebuffer driver for your ATI card.

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## Judge584

Hi

Thank-you for answer but I think you're wrong: with kms no framebuffer drivers are required.

Best regards.

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## Logicien

kms is there to set the console with appropriate framebuffer driver even if this driver is not compile in the kernel. The console get configure a bit later then if the driver was in the kernel, but reduce the need to recompile the kernel and make use of generics kernels more practical with a lot of hardware. When framebuffer driver is compile in module, you cannot pass parameters at kernel boot time to modify the framebuffer behavior. You must set parameters in /etc/modprobe.d to do so. If your console is blanked after the framebuffer driver load, it may be because it use wrong resolution, possibily an higher one then the screen support. You should check the parameters you can pass to the framebuffer module load by kms with the command modinfo and try to use one that will correct the problem. With Ati graphic cards I know radeonfb module.

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## Judge584

Ok, so I need to re-learn kms from scratch...all wiki on kms seems to say that we musn't select in-kernel framebuffer drivers si I don't understand.

Thx for answer.

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## audiodef

Well, all I can do is tell you what I've experienced and stand back. I've never had a good experience with KMS. Sure, it has sometimes worked, but it's often wonky. I'm not alone on this - other people who understand Gentoo far more than I are opposed to this whole KMS mess. 

At least TRY the fb driver. If it works, hey, whatever works, right? We should all focus on the result rather than the method.

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## cyrillic

No, you don't need any framebuffer drivers installed when you are using KMS, but you probably do want these settings in your kernel.

```
Device Drivers  --->

  Graphics support  --->

    Console display driver support  --->

      -*- VGA text console 
```

```
Kernel hacking  --->

  [*] Enable verbose x86 bootup info messages 
```

ps.  ATI with KMS works great on my machines.

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## Logicien

kms is just an helper for framebuffers drivers that support this feature of automating the setting of the resolution to the native of the screen. radeonfb and i915 support it. Without any generic or specific framebuffer driver I understand you get a blank screen, how can the kernel display something? Anyway I can miss something.

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## VoidMage

Last time I checked, radeonfb prevented KMS from working correctly.

The kernel option that's required here is CONFIG_FRAMEBUFFER_CONSOLE=y.

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## Judge584

Hi,

Sorry to insist but for me Cyrillic and Voidmage are right: no video framebuffer driver is needed, inside or outside the kernel.

I think the Framebuffer video thing is in the radeon DRM module: this what you can see on wiki's, and I think this is truth.

Anyway, thruth will be there in a few hours when I'll be at home, and of course I will post my results.

But whatever people here are right or wrong: I really would like to say thank-you trying to help me.

Best regards,

J.

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## Judge584

Ok, so Cyrillic and Voidmage were right!

In fact:

If you want to see messages during bzimage decompression, then you have to set:

```
Kernel hacking  --->

  [*] Enable verbose x86 bootup info messages 
```

If you want to see messages between bzimage decompression and kde login screen (too see services initialization), then you have to set:

```
Device Drivers  --->

  Graphics support  --->

    Console display driver support  --->

      -*- VGA text console 
```

On my system, the problem was here because the kernel option "VGA text console" was set as a module instead of in-kernel.

Now all is working like a charm.

Thanks again for all,

Best regards.

PS: for people how has problems with KMS, perhaps you should give it another try because on my system and appart for the small problem that is now resolved I never had any bug.

(I'm running all ~amd64 with an Ati 4870 Video card.)

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