Can anyone shed some light on this? I just installed the 64 bit version of FC5 and got this before and after doing a yum update. There is no option in my bios for the agp aperture size, I guess this is done automatically. I tried adding "iommu=memaper=2" to my grub line, no diference. I'm done googling now! Here's the deal:
$ dmesg | grep "agp"
agpgart: Detected AGP bridge 0
agpgart: Aperture conflicts with PCI mapping.
agpgart: Aperture from AGP @ f0000000 size 4096 MB
agpgart: Aperture too small (0 MB)
agpgart: No usable aperture found.
agpgart: Consider rebooting with iommu=memaper=2 to get a good aperture.
Linux agpgart interface v0.101 (c) Dave Jones
The funny thing is that all seems to work fine, I installed the nvidia drivers with no problems, glxgears scores fine, and yet:
$ cat /proc/driver/nvidia/agp/status
AGP initialization failed, please check the ouput
of the 'dmesg' command and/or your system log file
for additional information on this problem.
I never had this bother on the 32 bit version and I've done nothing to my bios or hardware setup, hmmm, and I was worried about losing flash & wine!