A Dell computer of mine running NetBSD 1.6 with the NetBSD xsrc version of 
XFree86 4.3.0 has an Intel 815 graphic chip.

The X server fails to start complaining I need /dev/agpgart
(EE) GARTInit: Unable to open /dev/agpgart (No such file or directory)

This should be provided by sys/dev/pci/agp_i810.c

I see the following in syslog:
  /netbsd: pchb0: Intel 82815 Hub (rev. 0x02)
  /netbsd: agp0 at pchb0: aperture at 0xf8000000, size 0x4000000
  /netbsd: vga1 at pci0 dev 2 function 0: Intel 82815 Graphics (rev. 0x02)

Here are the more detailed log lines:
(WW) I810(0): remove MTRR 0 - 1000
(--) I810(0): Chipset: "i815"
(--) I810(0): Linear framebuffer at 0xF8000000
(--) I810(0): IO registers at addr 0xFF000000
(EE) GARTInit: Unable to open /dev/agpgart (No such file or directory)
(EE) I810(0): AGP GART support is not available.  Make sure your kernel has
         agpgart support or that the agpgart kernel module is loaded.
(II) UnloadModule: "i810"
...
(EE) Screen(s) found, but none have a usable configuration.

Fatal server error:
no screens found

=========
I tried to create the device, using the major agp device in cdevs:
$ mknod  /dev/agpgart c 81 0

and it then fails similarly:
(WW) I810(0): remove MTRR 0 - 1000
(--) I810(0): Chipset: "i815"
(--) I810(0): Linear framebuffer at 0xF8000000
(--) I810(0): IO registers at addr 0xFF000000
(WW) xf86AcquireGART: AGPIOC_ACQUIRE failed (Invalid argument)
(EE) GARTInit: AGPIOC_INFO failed (Invalid argument)
(EE) I810(0): AGP GART support is not available.  Make sure your kernel has
         agpgart support or that the agpgart kernel module is loaded.
...
Fatal server error:
no screens found

===========

The XFree86 web site says two separate things:
1. I need to use " options         INSECURE " in my kernel
or the broken apNetBSD
2. And I need agpgart but it's not available for NetBSD.
But the agp_i810.c driver in NetBSD implies otherwise.

thanks,
-david