How to check actual mode loaded by GRUB1?

mloskot · 2012-06-05 01:50:23

Hi,

I'm having an impression, but GRUB1 ignores my vga setting in the kernel line of my /boot/grub/menu.lst
I used several modes, including vga=ask.
I also tried the vga=ask and select option 0 to go for normal 80x25 VGA.
In all cases, grub loads, displays first few messages as 80x25 VGA, then screen
refreshes, previous messages disappear and I get into higher resolution with framebuffer enabled.
Regardless of vga option used, I always end up with the same console resolution.

The only option to disable the higher resolution permanently is to add nomodeset in the kernel line.

I have 'default' Arch coniguration, with typical settings, no additional modules, no KMS, no Uvesafb used.

I sense there is something wrong with my boot-time configuration because I'm having problems with getting Polish keymap/consolefont set properly too.
Strangely, setting nomodeset option makes the consolefont/keymap work correctly (I mentioned here)

So, how can I check what is the actual mode set and how to check no two configurations (VESA, KMS+i985 driver) interfere?

DSpider · 2012-06-05 08:53:34

You mentioned i985, so that means Intel drivers. And since they are open source they will enable KMS by default. KMS is a good thing. It makes switching from tty7 to tt1 quicker, refreshes better, etc. It's an improvement.

https://wiki.archlinux.org/index.php/KMS

Intel, Nouveau and ATI drivers already enable KMS automatically for all chipsets.

https://wiki.archlinux.org/index.php/Gr … resolution

Scroll down for the hwinfo example.

$ sudo hwinfo --framebuffer

If you don't see the resolution you want in there, GRUB will ignore it and default to 640x480 (or 800x600, I don't remember).

mloskot · 2012-06-05 22:05:31

DSpider wrote:

You mentioned i985, so that means Intel drivers. And since they are open source they will enable KMS by default. KMS is a good thing. It makes switching from tty7 to tt1 quicker, refreshes better, etc. It's an improvement.
https://wiki.archlinux.org/index.php/KMS
Intel, Nouveau and ATI drivers already enable KMS automatically for all chipsets.

So, AFAIU, the "Late KMS start" kicks in and the driver is loaded by default. That would explain why the vga= option is ignored as per the KMS Wiki:

Any "vga=" options in your bootloader as these will conflict with the native resolution enabled by KMS.

DSpider wrote:

https://wiki.archlinux.org/index.php/Gr … resolution
Scroll down for the hwinfo example.
$ sudo hwinfo --framebuffer
If you don't see the resolution you want in there, GRUB will ignore it and default to 640x480 (or 800x600, I don't remember).

I see all the resolutions I have tried to set with vga= option.
Here is the full list:

[mloskot@dog ~]$ sudo hwinfo --framebuffer
Password: 
02: None 00.0: 11001 VESA Framebuffer                           
  [Created at bios.459]
  Unique ID: rdCR.fRULN9k9OD4
  Hardware Class: framebuffer
  Model: "Intel(r)Cantiga Graphics Controller"
  Vendor: "Intel Corporation"
  Device: "Intel(r)Cantiga Graphics Controller"
  SubVendor: "Intel(r)Cantiga Graphics Chip Accelerated VGA BIOS"
  SubDevice: 
  Revision: "Hardware Version 0.0"
  Memory Size: 31 MB + 960 kB
  Memory Range: 0xd0000000-0xd1feffff (rw)
  Mode 0x0360: 768x480 (+768), 8 bits
  Mode 0x0361: 768x480 (+1536), 16 bits
  Mode 0x0362: 768x480 (+3072), 24 bits
  Mode 0x0363: 960x600 (+960), 8 bits
  Mode 0x0364: 960x600 (+1920), 16 bits
  Mode 0x0365: 960x600 (+3840), 24 bits
  Mode 0x0366: 1280x800 (+1280), 8 bits
  Mode 0x0367: 1280x800 (+2560), 16 bits
  Mode 0x0368: 1280x800 (+5120), 24 bits
  Mode 0x0369: 1440x900 (+1472), 8 bits
  Mode 0x036a: 1440x900 (+2880), 16 bits
  Mode 0x036b: 1440x900 (+5760), 24 bits
  Mode 0x0305: 1024x768 (+1024), 8 bits
  Mode 0x0317: 1024x768 (+2048), 16 bits
  Mode 0x0318: 1024x768 (+4096), 24 bits
  Mode 0x0312: 640x480 (+2560), 24 bits
  Mode 0x0314: 800x600 (+1600), 16 bits
  Mode 0x0315: 800x600 (+3200), 24 bits
  Mode 0x0301: 640x480 (+640), 8 bits
  Mode 0x0303: 800x600 (+832), 8 bits
  Mode 0x0311: 640x480 (+1280), 16 bits
  Config Status: cfg=new, avail=yes, need=no, active=unknown
[mloskot@dog ~]$

I have tried modes like 0x0365 or 0x0367, but assuming that in my case the KMS kicks in, these vga= modes I have tried were ignored.

I will see if I can get the "Early KMS start" configured and "Forcing modes" too. I'll report back soon.

Thanks for help!

mloskot · 2012-06-06 00:38:46

mloskot wrote:

I have tried modes like 0x0365 or 0x0367, but assuming that in my case the KMS kicks in, these vga= modes I have tried were ignored.

I removed the vga option from the kernel line in /boot/grub/menu.lst and there is "visual" difference at early stage of boot.

With the vga, the screen switches between no mode to the one specified with the vga option for 1-2 seconds,
then it flickers and switches to another mode. Presumably, the final mode is set by the KMS default.

After removing the vga option, there is no intermediate mode change, but the screen switches directly to the KMS default mode.

DSpider · 2012-06-06 10:32:55

After removing the vga option, there is no intermediate mode change, but the screen switches directly to the KMS default mode.

Early Start will change the resolution as soon as the bootloader loads initramfs-linux.img. But the resolution from GRUB is a GRUB setting.

You can try the vbetest method to get your values but I have a feeling that it won't work either. If you check out the Intel article it says:

Note: When using KMS, you must remove any references to vga or nomodeset from the kernel line in /boot/grub/menu.lst

Also: https://wiki.archlinux.org/index.php/KMS#Installation

At first, note that for any method you use, you should always disable:
- Any "vga=" options in your bootloader as these will conflict with the native resolution enabled by KMS.
- Any "video=" lines that enable a framebuffer that conflicts with the driver.
- Any other framebuffer drivers (such as uvesafb).

And the Nouveau and Radeon articles say the exact same thing. Absolutely no "vga" in there.

Arch Linux

#1 2012-06-05 01:50:23

How to check actual mode loaded by GRUB1?

#2 2012-06-05 08:53:34

Re: How to check actual mode loaded by GRUB1?

#3 2012-06-05 22:05:31

Re: How to check actual mode loaded by GRUB1?

#4 2012-06-06 00:38:46

Re: How to check actual mode loaded by GRUB1?

#5 2012-06-06 10:32:55

Re: How to check actual mode loaded by GRUB1?

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