BootX and kernel args

[Alexander Holst]

Hi Isaac,

Am Dienstag, 23.09.03, um 16:53 Uhr (Europe/Berlin) schrieb 
yellowdog-general-request@lists.terrasoftsolutions.com:

> Message: 2
> Subject: Re: BootX and kernel args
> From: mascarasnake <dontdrill@earthlink.net>
> To: yellowdog-general@lists.terrasoftsolutions.com
> Organization:
> Date: 22 Sep 2003 15:34:21 -0400
> Reply-To: yellowdog-general@lists.terrasoftsolutions.com
>
> On Mon, 2003-09-22 at 15:02, Isaac Wingfield wrote:
>> Thanks for the suggestions, but I think I need to be a little more 
>> clear:
>>
>> X works fine. The problem is that I cannot read the screen *except* 
>> when X
>> is running, because my monitor loses sync.
>>
>> It's *before* X takes over that I need to change the screen 
>> parameters, but
>> kernel args in BootX don't seem to do anything.
>>
>> I've tried "video=atyfb:vmode=18:cmode=16" and several variations on 
>> that
>> theme, but nothing I've tried changes the screen res during the text 
>> part
>> of the boot process. BootX won't even *leave it alone*, the way the 
>> Mac set
>> it up.

AFAIK, as soon as the arch exit appears on the screen, the kernel takes 
over the video settings. On my beige G3, without any video kernel 
arguments, the screen falls back onto 1024x768@75Hz, no matter what the 
resolution was set to before by either MacOS or via nvvideo.

> Sorry, Isaac, I misunderstood the problem, But I still think it's
> probably a miscommunication between your monitor, video card and Linux.
> A wee bit over my head at this point. Have you tried booting up from 
> the
> Install CD w/the  boot kernel/ram disk combo when you initially
> installed Linux to see what the res is like?

Did you try different combinations of the "No video driver" (on the 
main panel) and "Force video settings" (in the options section)?

I have no idea, which is responsible for making the kernel ignore the 
video=... kernel argument. I remember having some issues on my beige G3 
as well, when using BootX, that's why I switched to miBoot, which 
avoids loading any part of MacOS prior to loading the kernel, therefore 
all kernel arguments are honored the way they should. If you need any 
instructions on how to setup miBoot, contact me.

Just for the sake of it, have you had a look into the output of dmesg, 
what the actual kernel argumet line was - it should be found within the 
first few lines of that output.

Another idea: as your monitor is not a Mac monitor, how did you attach 
your monitor to the Mac? Did you use a connector with DIP switches to 
set the mode for the monitor? If yes, you must use a MultiSync setting, 
otherwise the Mac screws up as its builtin video thinks the monitor is 
a single res monitor and might have weird signals going out to the 
monitor.

Normally, all MultiSync monitors should be able to do 640x480@60Hz, 
which is VGA. Therefore, on a console (even if you cannot see anything 
at the beginning and have to type blindly), you should be able to login 
and run the command "fbset 640x480-60", without the quotes, and get 
into a usable resolution. From that point on, you can try the different 
settings which can be found in /etc/fb.modes. The syntax for the fbset 
command is: "fbset HORIZONTALxVERTICAL-FREQ". The desired mode has to 
be defined in /etc/fb.modes, otherwise fbset will complain. I will send 
you my /etc/fb.modes later today, so you can try and see, if my 
1152x870-75 mode works for you.


Greetings,
Alex

Alexander Holst
Pforzheim University of Applied Sciences
<holst@fh-pforzheim.de>
ph: +49 [0]7231 28-6837
fx: +49 [0]7231 28-6040