fxp(4) vs "too much" RAM?

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

I've been investigating an Intel Desktop Board D946GZIS equipped with
a Core 2 Duo E4300@1.8GHz.

Intel's documentation claims the maximum RAM for the board/chipset is
4GB.  I've also experimentally installed 8GB of RAM and while the BIOS
can't make heads or tails of it, the NetBSD kernel and MemTest86+ see
it just fine.

If I install said 4GB or more RAM, however, the on-board fxp(4) interface
goes deaf when the NetBSD kernel boots.  Based on the logs from my DHCP
server, it sends DHCPDISCOVER but never gets the DHCPOFFER.

The PXE BIOS works fine, the 'pxeboot_ia32.bin' program works fine.  It's
just the "fxp(4)" driver in the kernel that has problems with "too much"
memory.

If I install 3GB or less RAM, the on-board fxp(4) interface works
properly when NetBSD boots.

Observed with NetBSD/amd64-7.1_STABLE (local disk) and -current
(8.99.1 via netboot--almost).

Sound familiar to anyone?  Need more details?

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