玄箱（Ubuntu14.04:PowerPC）で利用可能なsources.listの日本語情報が無かったので記載。natty向けになっているので
:s/natty/trusty/g
で名前を変更して使用してください。
# deb http://ports.ubuntu.com/ubuntu-ports/ natty main restricted

# deb http://ports.ubuntu.com/ubuntu-ports/ natty-updates main restricted
# deb http://security.ubuntu.com/ubuntu natty-security main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ natty main restricted
deb-src http://archive.ubuntu.com/ubuntu natty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ natty-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu natty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://ports.ubuntu.com/ubuntu-ports/ natty universe
deb-src http://archive.ubuntu.com/ubuntu natty universe
deb http://ports.ubuntu.com/ubuntu-ports/ natty-updates universe
deb-src http://archive.ubuntu.com/ubuntu natty-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://ports.ubuntu.com/ubuntu-ports/ natty multiverse
deb-src http://archive.ubuntu.com/ubuntu natty multiverse
deb http://ports.ubuntu.com/ubuntu-ports/ natty-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu natty-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://ports.ubuntu.com/ubuntu-ports/ natty-backports main restricted universe multiverse
# deb-src http://archive.ubuntu.com/ubuntu natty-backports main restricted universe multiverse

deb http://ports.ubuntu.com/ubuntu-ports/ natty-security main restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ natty-security main restricted
deb http://ports.ubuntu.com/ubuntu-ports/ natty-security universe
deb-src http://ports.ubuntu.com/ubuntu-ports/ natty-security universe
deb http://ports.ubuntu.com/ubuntu-ports/ natty-security multiverse
deb-src http://ports.ubuntu.com/ubuntu-ports/ natty-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu natty partner
# deb-src http://archive.canonical.com/ubuntu natty partner

## Uncomment the following two lines to add software from Ubuntu's
## 'extras' repository.
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
# deb http://extras.ubuntu.com/ubuntu natty main
# deb-src http://extras.ubuntu.com/ubuntu natty main
元情報　https://ubuntuforums.org/showthread.php?t=1842883&page=2&p=11266820#post11266820