My intel '486 fails to netboot with a current kernel (supped
yesterday). This machine loads a kernel from disk and then
continues to boot over NFS. It fails with the following
messages and ending up in the kernel debugger:

nfs_boot: trying RARP (and RPC/bootparam)
uvm_fault(0xf022d31c, 0x0, 0, 1) -> 5
kernel: page fault trap, code=0
stopped in swapper at  _we_write_mbuf+0x2ab: movl    0x1c(%edx),%ebx

Two other kernels build from the same sources work fine, although
those are not used for netbooting nor use the we ethernet driver.

Any ideas?

Feico.