Error Kernel Compiling

[Federico Cicciarella]

linking kernel.debug
if.o(.text+0x1027): In function `if_setlladdr':
/usr/src/sys/net/if.c:2646: undefined reference to `arp_ifinit'
igmp.o(.text+0x45): In function `igmp_sendpkt':
/usr/src/sys/netinet/igmp.c:472: undefined reference to `loif'
ip_output.o(.text+0xae9): In function `ip_output':
/usr/src/sys/netinet/ip_output.c:1196: undefined reference to `if_simloop'
ip_output.o(.text+0xcfe):/usr/src/sys/netinet/ip_output.c:451: undefined reference to `loif'
ip6_input.o(.text+0xedf): In function `ip6_input':
/usr/src/sys/netinet6/ip6_input.c:254: undefined reference to `loif'
ip6_output.o(.text+0x10a): In function `ip6_mloopback':
/usr/src/sys/netinet6/ip6_output.c:3258: undefined reference to `if_simloop'
ip6_output.o(.text+0x3bad): In function `ip6_output':
/usr/src/sys/netinet6/ip6_output.c:845: undefined reference to `loif'
nd6.o(.text+0x2d77): In function `nd6_rtrequest':
/usr/src/sys/netinet6/nd6.c:1334: undefined reference to `loif'
*** Error code 1

Stop in /usr/obj/usr/src/sys/MYKERNEL.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.



Why?