Look like if OpenFirmware boot from the NIC, it don't initialize the
disk(s) immediatly :

If the NIC is used to get the loader from the network and let the loader
get the kernel from a FFS partitions.
It's possible that OpenFirmware configure the interface and get the
ofwboot.[elf,xcf] file from the TFTP server fast enough to run ofwboot
without even finish to initialize the disk containing the kernel.
ofwboot will fail because it can't open the device.

It's possible that it can't affect slow Mac as a 6400 with 10BaseT NIC,
but I saw that on a 7300. Probably lot's of Mac with slow disk on a fast
network (like switch with Spanning-Tree PortFast) can't boot from enet.
To avoid that I use a floppy to get ofwboot.xcf the time spent to
initialize the floppy and read the file let OF finish to initialize the
disk.

Maybe that situation could be documented in macppc installation doc.

On Tue, 2001-09-25 at 12:42, Henry B. Hotz wrote:

    If you are booting the installation kernel from floppy then it 
    doesn't matter if OF supports the NIC.  Just so long as NetBSD 
    supports it.