Current set of bootstrappable packages in quantal:

dose-builddebcheck -s --deb-native-arch=amd64 --deb-foreign-archs=armhf,linux-any --deb-host-arch=armhf /var/lib/apt/lists/uk.archive.ubuntu.com_ubuntu_dists_quantal_main_binary-amd64_Packages /var/lib/apt/lists/_home_wookey_linaro_armv8_repo_dists_quantal-bootstrap_main_source_Sources | grep package | sed 's.%3a.:.g' | awk -F: '{ print $4 }'

(Note that 'native-arch' means 'build-arch' in dose terminology)

adduser base-files base-passwd busybox bzip2 cpio dash debconf debianutils diffutils hostname ifupdown insserv langpack-locales libsepol mawk mime-support module-init-tools pcre3 zlib

This is the set of things that have no native dependencies.

Once you start building those packages you can make progress and see what else can be built by adding the local host-arch binary package list. dose-builddebcheck -s --deb-native-arch=amd64 --deb-foreign-archs=armhf,linux-any --deb-host-arch=armhf /var/lib/apt/lists/uk.archive.ubuntu.com_ubuntu_dists_quantal_main_binary-amd64_Packages /var/lib/apt/lists/_home_wookey_linaro_armv8_repo_dists_quantal-bootstrap_main_binary-armhf_Packages /var/lib/apt/lists/_home_wookey_linaro_armv8_repo_dists_quantal-bootstrap_main_source_Sources | grep package | sed 's.%3a.:.g' | awk -F: '{ print $4 }'