/usr/share/live/build/templates/yaboot/yaboot.conf is in live-build 3.0~a57-1ubuntu11.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | default=live
message=/yaboot/boot.msg
LINUX_LIVE
LINUX_INSTALL
|