How do I force a particular KMS native resolution for a monitor that lacks EDID?

[Alex Villací­s Lasso]

Maybe this is not the proper list for this question. If this is so, 
please indicate the proper place for this question.

I have a Fedora 12 x86_64 system, with an intel video chipset. This 
system uses a Princeton flat panel connected through a standard VGA 
cable. This flat panel is odd since it does not report any EDID data to 
the video chipset, and therefore cannot inform the system of its maximum 
resolution. However, through trial and error, I found out that the 
maximum native resolution is 1280x1024.

I know this is not a chipset or driver problem, because a different 
(older) monitor plugged in the same system does report EDID information.

The issue is that KMS, in the absence of EDID information, wants to use 
a default resolution of 1024x768 (was 800x600 until I upgraded the 
distro kernel), which underutilizes the monitor. Unless I take action, 
this suboptimal resolution persists through all the boot process and 
into the graphical desktop and any virtual consoles. I have added a 
xorg.conf file to specify the 1280x1024 mode, and it works - for the 
graphical desktop only. I have also added video=1280x1024 as a kernel 
parameter in my grub.conf file, and it also works - for the virtual 
consoles only. However, I cannot find yet a way to make plymouth use 
1280x1024 as the resolution for the graphical boot. What happens instead 
is that the kernel switches into 1280x1024, then plymouth switches back 
into 1024x768 for the duration of the graphical boot, and only changes 
back into 1280x1024 when the graphical login takes over.

Is there a way to specify the KMS screen resolution for plymouth, or 
else to make plymouth (and hopefully X) use the 1280x1024 setting that 
was already set by way of kernel parameters? I have tried googling 
around and there seems to be no information on how to do this, or 
whether this is even possible.