Have you done a 'mk clean' in the /sys/src/9/pc directory and tried again?  It looks
like the files:
	ethermedium.8
	netdevmedium.8
	loopbackmedium.8
are screwed up.  These files should have those symbols defined.

Also, make sure that those .8's appear in the list of args when 8l links the
kernel.  For example:

8l -o 9pcauth -T0x80100020 -l l.8 plan9l.8 cga.8 i8253.8 i8259.8 kbd.8 main.8 memory.8 mmu.8 random.8 rdb.8 trap.8 pcauth.root.8 pcauth.rootc.8 vga.8 ether82557.8 uarti8250.8 sdata.8 devmnt.8 iproute.8 devtls.8 devdup.8 devenv.8 tcp.8 apm.8 devsd.8 vgax.8 devarch.8 ipifc.8 devether.8 chandial.8 devsrv.8 icmp.8 ethermedium.8 devcap.8 devproc.8 dma.8 devmouse.8 devrtc.8 devfloppy.8 ip.8 udp.8 ipv6.8 devcons.8 devpnp.8 il.8 devuart.8 arp.8 uartpci.8 screen.8 devip.8 ptclbsum386.8 devkprof.8 pktmedium.8 vgamach64xx.8 ipaux.8 devpipe.8 loopbackmedium.8 apmjump.8 devfs.8 sdscsi.8 inferno.8 devroot.8 netlog.8 devvga.8 mouse.8 devdraw.8 devssl.8 nullmedium.8 netif.8 pci.8 icmp6.8 netdevmedium.8 alarm.8 alloc.8 allocb.8 auth.8 cache.8 chan.8 dev.8 fault.8 latin1.8 nulledf.8 page.8 parse.8 pgrp.8 portclock.8 print.8 proc.8 qio.8 qlock.8 rebootcmd.8 segment.8 swap.8 sysfile.8 sysproc.8 taslock.8 tod.8 xalloc.8 pcauth.8 /386/lib/libmemlayer.a /386/lib/libmemdraw.a /386/lib/libdraw.a /386
 /lib/libc.a /386/lib/libsec.a

If not, something else is wrong and we can bang at it off line.