p Most executables will work. The exceptions include programs that use proprietary, Ultrix-specific features (LAT, CI support, DECnet support) and various system calls, ioctl()'s, or Ultrix kernel semantics that are difficult to emulate (e.g., Ultrix packetfilter) or buggy (e.g., Ultrix YP).
p All Ultrix executables are static, so no shared libraries are required for Ultrix compatiblity. However, Ultrix is based on a 4.3BSD alpha release. Ultrix commands and libraries are often much older than their NetBSD or even SunOS 4.x equivalents, and may require incompatible configuration files. .Sh SYSTEM CONFIGURATION FILES Set up resolv.conf and svc.conf as below:
p l -tag -width 123 -compact -offset indent t # mkdir -p /emul/ultrix/etc t # cd /emul/ultrix/etc t # egrep 'domain|nameserver' /etc/resolv.conf > ./resolv.conf t # cp -p /usr/share/samples/emul/ultrix/etc/* ./ .El
p .Ss /etc/resolv.conf The Ultrix resolver library only understands .Sy domain and .Sy nameserver lines in .Xr /etc/resolv.conf 5 . You should create a copy of /etc/resolv.conf containing only those commands and put it in /emul/ultrix/etc/resolv.conf. Note that the domain search order used by Ultrix executables may not be the same as native binaries; there is no good way around this.
p .Ss /etc/svc.conf Ultrix uses /etc/svc.conf to select an ordered search of YP, Hesiod, or local flat-file mappings. You should create an /emul/ultrix/etc/svc.conf specifying either local files or bind (DNS) lookups for all Ultrix name services. .Sh BUGS
p RISC Ultrix YP(NIS) is know to not work. The Ultrix YP libraries have a consistent endian-ness bug. Ultrix YP client will not inter-operate with the NetBSD .Xr ypbind 8 process. The only workaround is to use /etc/svc.conf to disable YP(NIS).
p The ndbm hashed-password file used by Ultrix are incompatible with the db hashed-password file used by NetBSD. There is no good solution for this. (YP would be a good one, if Ultrix YP worked.)
p The API used by Xservers to talk to the kernel is currently compatible with Ultrix 4.1. An implementation of the Ultrix 4.2 Xws interface (used by X11R6) is in progress.
p A complete list of things which fail to work in Ultrix compatibility mode should be added here. .Sh SEE ALSO .Xr resolv.conf 5 .