Thanks for the reply. Actually I tried something similiar, but not as complete. I added the chipset ID to the kernel/include/pci_ids.h table (BTW I also added this to the list at sourceforge to get updated). However, I did not add anything to agpgart_be.c . I then recompiled my kernel with agpgart as a module. Then I loaded it from modules.conf w/:
alias char-major-10-175 agpgart
option agpgart agp_try_unsupported=1
When the module loads it says it is using the VIA generic routine for AGP. Loading at 0e000000. That is what dmesg says and the module appears to load OK.
However, when it actually gets "used" by NVdriver during the start of X, that is when it crashes...hard.
I thought of hacking the module like you suggest, but I am thinking that if AGP for VT8754 is the same as the other chipsets, then the VIA generic routine would have worked fine, but it didn't. I read somewhere that VIA claims the chipset is backwards compatible, hence there shouldn't be any change. But this chipset supports 8Xagp also. So maybe there is something different? I ended up putting win2000 on this box and am very unhappy. But I also realize it will take time before the chipset will be supported better in my OS of choice. I gotta have 4Xagp for gaming! Also to note, Is there anyone with 4Xagp/NVidia drivers working with the KT400 and a GF4?
Another idea. I have a geforce3 in my kid's box running Slackware. I could switch out the cards. Though my GF4 was working fine when it was on my abit board 6 days ago running under Slackware, and seems to work fine under windows now.
I will drop another drive in and reinstall linux just to hack the agpgart kernel module and see if I can get it with that "long shot"
I also can ask VIA for the chipset specifications etc and see if maybe it is different that I can figure it out. Or maybe someone from Nvidia or VIA could help out on this one?