Merge branch 'feature/use-shld'

35 files changed, 3131 insertions, 37 deletions

diff --git a/src/archplat.sh b/src/archplat.sh
new file mode 100644
index 0000000..b8324a0
--- /dev/null
+++ b/src/archplat.sh
@@ -0,0 +1,144 @@
+# Functions for matching architectures and platforms
+#
+# Copyright (C) 2012  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+match_arch()
+{
+	local arch="${1}"
+	local arch_field="${2}"
+	local a=
+	local a_ere=
+
+	for a in ${arch_field}; do
+
+		# "all" == "all"
+		if [ "${arch}" = 'all' ]; then
+			if [ "${a}" = 'all' ]; then
+				return 0
+			else
+				continue
+			fi
+		fi
+
+		# "foo-bar-baz" == "any"
+		if [ "${a}" = 'any' ]; then
+			return 0
+		fi
+
+		# Generate an ERE to match hyphenated architectures.
+		a_ere="$(printf '%s\n' "${a}" | sed \
+			's/^any-/[^-]+-/;s/-any-/-[^-]+-/g;s/-any$/-[^-]+/g')"
+
+		# "foo-bar-baz" == "foo-any-any"
+		if echo "${arch}" | grep -E "${a_ere}" >/dev/null 2>&1; then
+			return 0
+		fi
+
+	done
+
+	# Nothing matched.
+	return 1
+}
+
+match_plat()
+{
+	local plat="${1}"
+	local plat_field="${2}"
+	local p=
+
+	for p in ${plat_field}; do
+		if [ "x${plat}" = 'xall' ]; then
+			if [ "x${p}" = 'xall' ]; then
+				return 0
+			else
+				continue
+			fi
+		fi
+		if [ "x${p}" = 'xany' ]; then
+			return 0
+		fi
+		if [ "x${p}" = "x${plat}" ]; then
+			return 0
+		fi
+	done
+
+	return 1
+}
+
+arch_is_concerned()
+{
+	local host_arch="${1}"
+	local arches="${2}"
+	local arch=
+	local not_arch=
+	local seen_arch=
+
+	if [ "x${arches}" = 'x' ]; then
+		return 0
+	else
+		seen_arch=1
+		for arch in ${arches}; do
+			not_arch="${arch#!}"
+			if [ "x${not_arch}" != "x${arch}" ]; then
+				if match_arch "${host_arch}" "${not_arch}"
+				then
+					seen_arch=1
+					break
+				elif [ "x${host_arch}" != 'xall' ]; then
+					seen_arch=0
+				fi
+			elif match_arch "${host_arch}" "${arch}"; then
+				seen_arch=0
+				break
+			fi
+		done
+		return ${seen_arch}
+	fi
+}
+
+plat_is_concerned()
+{
+	local host_plat="${1}"
+	local plats="${2}"
+	local plat=
+	local not_plat=
+	local seen_plat=
+
+	if [ "x${plats}" = 'x' ]; then
+		return 0
+	else
+		seen_plat=1
+		for plat in ${plats}; do
+			not_plat="${plat#!}"
+			if [ "x${not_plat}" != "x${plat}" ]; then
+				if match_plat "${host_plat}" "${not_plat}"
+				then
+					seen_plat=1
+					break
+				elif [ "x${host_plat}" != 'xall' ]; then
+					seen_plat=0
+				fi
+			elif match_plat "${host_plat}" "${plat}"; then
+				seen_plat=0
+				break
+			fi
+		done
+		return ${seen_plat}
+	fi
+}
diff --git a/src/block.sh b/src/block.sh
new file mode 100644
index 0000000..f056305
--- /dev/null
+++ b/src/block.sh
@@ -0,0 +1,86 @@
+# Functions for mounting and unmounting block devices
+#
+# Copyright (C) 2015  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+is_block()
+{
+	local dev="${1}"
+
+	[ -b "${dev}" ]
+	return ${?}
+}
+
+check_block()
+{
+	local dev="${1}"
+
+	if ! [ -b "${dev}" ]; then
+		error 2 "$(get_msg 'block_device_invalid')" "${dev}"
+	fi
+}
+
+block_mount()
+{
+	local dev="${1}"
+	local dir=
+
+	check_block "${dev}"
+
+	rand
+	dir="$(get_vardata_dir 'mount')/block-$(printf '%010d' ${rand_x})"
+	if ! mkdir "${dir}"; then
+		error 2 "$(get_msg 'block_mkdir_fail')" "${dir}"
+	fi
+
+	if ! mount "${dev}" "${dir}"; then
+		rmdir "${dir}"
+		error 2 "$(get_msg 'block_mount_fail')" "${dev}"
+	fi
+
+	printf '%s' "${dir}"
+	return 0
+}
+
+block_umount()
+{
+	local dir="${1}"
+	local i=
+	local timed_out=
+
+	i=0
+	timed_out=false
+	while ! umount "${dir}"; do
+		i=$(($i + 1))
+		if [ ${i} -eq 10 ]; then
+			timed_out=true
+			break
+		fi
+		sleep 1
+	done
+
+	if ${timed_out}; then
+		error 2 "$(get_msg 'block_umount_fail')" "${dir}"
+	fi
+
+	if ! rmdir "${dir}"; then
+		error 2 "$(get_msg 'block_rmdir_fail')" "${dir}"
+	fi
+
+	return 0
+}
diff --git a/src/cmd.sh b/src/cmd.sh
new file mode 100644
index 0000000..d4e7824
--- /dev/null
+++ b/src/cmd.sh
@@ -0,0 +1,122 @@
+# Command-related functions
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmds=' '
+running_cmd=
+running_cmd_clean=
+
+register_cmd()
+{
+	local cmd="${1}"
+	shift 1
+
+	cmds="${cmds}${cmd} "
+	return 0
+}
+
+print_opt_summaries()
+{
+	local padding=
+	local opt=
+	local opt_out=
+	local summary=
+
+	padding="$(printf '%24s' '')"
+	for opt in $(printf '%s' "${OPTSTRING}" | sed 's/\([a-zA-Z0-9]\)/ \1/g')
+	do
+		if [ ${#opt} -eq 1 ]; then
+			# No argument expected.
+			opt_out="-${opt}"
+		else
+			# Argument expected.
+			opt="${opt%?}"
+			opt_out="-${opt} $(get_msg "opt_${opt}_arg")"
+		fi
+		if [ ${#opt_out} -gt 20 ]; then
+			printf '  %s\n%24s' "${opt_out}" ''
+		else
+			printf '  %-20s  ' "${opt_out}"
+		fi
+		summary="$(get_msg "opt_${opt}_summary")"
+		printf '%s\n' "${summary}" | fold -s -w 56 | \
+			sed "2,\$s/^/${padding}/;"
+	done
+}
+
+print_cmd_summaries()
+{
+	local padding=
+	local cmd=
+	local cmd_clean=
+	local summary=
+
+	padding="$(printf '%24s' '')"
+	for cmd in ${cmds}; do
+		if [ ${#cmd} -gt 20 ]; then
+			printf '  %s\n%24s' "${cmd}" ''
+		else
+			printf '  %-20s  ' "${cmd}"
+		fi
+		cmd_clean="$(printf '%s' "${cmd}" | \
+			tr '[A-Z]' '[a-z]' | tr -C '[a-z0-9_]' '_')"
+		summary="$(get_msg "cmd_${cmd_clean}_summary")"
+		printf '%s\n' "${summary}" | fold -s -w 56 | \
+			sed "2,\$s/^/${padding}/;"
+	done
+}
+
+print_cmd_usage()
+{
+	local cmd="${1}"
+	local cmd_clean=
+	local usage=
+
+	cmd_clean="$(printf '%s' "${cmd}" | \
+		tr '[A-Z]' '[a-z]' | tr -C '[a-z0-9_]' '_')"
+	usage="$(get_msg "cmd_${cmd_clean}_usage")"
+
+	printf "$(get_msg 'cmd_usage')\n" "${0}" "${cmd}" "${usage}"
+}
+
+is_cmd()
+{
+	local cmd="${1}"
+
+	[ "x$(printf '%s\n' ${cmds} | grep "^${cmd}$")" = "x${cmd}" ]
+}
+
+run_cmd()
+{
+	local cmd="${1}"
+	local cmd_clean=
+	shift
+
+	cmd_clean="$(printf '%s' "${cmd}" | \
+		tr '[A-Z]' '[a-z]' | tr -C '[a-z0-9_]' '_')"
+	if is_cmd "${cmd}"; then
+		running_cmd="${cmd}"
+		running_cmd_clean="${cmd_clean}"
+		"cmd_${cmd_clean}_main" "${@}"
+		running_cmd=''
+		running_cmd_clean=''
+	else
+		error 1 "$(get_msg 'cmd_not_found')" "${cmd}"
+	fi
+}
diff --git a/src/cmd/build.sh b/src/cmd/build.sh
new file mode 100644
index 0000000..8d12691
--- /dev/null
+++ b/src/cmd/build.sh
@@ -0,0 +1,152 @@
+# "build" command
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_build_root=
+cmd_build_pkg_dir=
+cmd_build_build_deps=
+
+cmd_build_main()
+{
+	local root=
+	local dev=
+	local opkbuild_optstring=
+	local arch=
+	local plat=
+	local first_arg=
+	local arg=
+
+	if [ ${#} -lt 2 ]; then
+		print_cmd_usage 'build' >&2
+		exit 1
+	fi
+
+	root="${1}"
+	shift 1
+
+	dev=''
+	if is_block "${root}"; then
+		dev="${root}"
+		root="$(block_mount "${dev}")"
+	fi
+
+	cmd_build_root="${root}"
+
+	opkbuild_optstring="$(cat "${root}/usr/share/opkbuild/optstring")"
+	arch="$(cat "${root}/etc/proteanos_arch")"
+	plat="$(cat "${root}/etc/proteanos_plat")"
+	while getopts "${opkbuild_optstring}" opt 2>/dev/null; do
+		case "${opt}" in
+			a) arch="${OPTARG}";;
+			p) plat="${OPTARG}";;
+		esac
+	done
+
+	first_arg=true
+	cmd_build_pkg_dir=''
+	for arg in "${@}"; do
+		if ${first_arg}; then
+			set --
+			first_arg=false
+		else
+			set -- "${@}" "${cmd_build_pkg_dir}"
+		fi
+		cmd_build_pkg_dir="${arg}"
+	done
+
+	. "${root}/etc/os-release"
+	profile_set "${ID}"
+
+	if ! [ -d "${cmd_build_pkg_dir}" ]; then
+		error 2 "$(get_msg 'cmd_build_not_a_dir')" \
+			"${cmd_build_pkg_dir}"
+	fi
+	package_init "${cmd_build_pkg_dir}"
+	package_set_substvars "${arch}" "${plat}"
+
+	session_begin "${root}" "${cmd_build_pkg_dir}" cmd_build_fini false
+
+	cmd_build_build_deps="$(package_get_build_deps "${arch}" "${plat}")"
+	if [ "x${cmd_build_build_deps}" != 'x' ]; then
+		cmd_build_make_deps_pkg
+		session_exec opkg install ../builddeps.opk
+	fi
+
+	session_exec opkbuild "${@}"
+
+	cmd_build_fini
+
+	session_end
+
+	if [ "x${dev}" != 'x' ]; then
+		block_umount "${root}"
+	fi
+}
+
+cmd_build_make_deps_pkg()
+{
+	local pkg_dir=
+
+	pkg_dir="${cmd_build_root}$(session_dir)/builddeps"
+	mkdir -p "${pkg_dir}/control" "${pkg_dir}/data"
+	printf '2.0\n' >"${pkg_dir}/debian-binary"
+	cat >"${pkg_dir}/control/control" <<-EOF
+		Package: prokit-builddeps-$(session_id)
+		Source: prokit
+		Version: 1.0
+		Architecture: all
+		Platform: all
+		Depends: ${cmd_build_build_deps}
+		Description: Build dependencies metapackage generated by prokit
+		EOF
+	(cd "${pkg_dir}/data"; tar -czf ../data.tar.gz .)
+	(cd "${pkg_dir}/control"; tar -czf ../control.tar.gz .)
+	(cd "${pkg_dir}"; tar -czf ../builddeps.opk \
+		'debian-binary' 'data.tar.gz' 'control.tar.gz')
+	rm -Rf "${pkg_dir}"
+}
+
+cmd_build_fini()
+{
+	local session_dir=
+	local f=
+
+	session_dir="$(session_dir)"
+
+	if [ "x${cmd_build_build_deps}" != 'x' ]; then
+		session_exec opkg --autoremove remove \
+			prokit-builddeps-$(session_id)
+		rm "${cmd_build_root}${session_dir}/builddeps.opk"
+		# Hack to avoid this code branch if the function is called again
+		# in response to a signal.
+		cmd_build_build_deps=''
+	fi
+
+	for f in "${cmd_build_root}${session_dir}/"*; do
+		[ -e "${f}" ] || continue
+		[ "x${f##*/}" = 'xwd' ] && continue
+		mv "${f}" "${cmd_build_pkg_dir}/.."
+	done
+}
+
+cmd_build_register()
+{
+	register_cmd 'build'
+}
+__init cmd_build_register
diff --git a/src/cmd/help.sh b/src/cmd/help.sh
new file mode 100644
index 0000000..c699c73
--- /dev/null
+++ b/src/cmd/help.sh
@@ -0,0 +1,47 @@
+# "help" command
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_help_main()
+{
+	local cmd=
+
+	if [ ${#} -eq 1 ]; then
+		cmd="${1}"
+		if is_cmd "${cmd}"; then
+			print_cmd_usage "${cmd}"
+			return 0
+		fi
+	fi
+
+	printf "$(get_msg 'cmd_help_head')\n\n" "${0}"
+
+	printf "$(get_msg 'cmd_help_opts_head')\n"
+	print_opt_summaries
+	printf '\n'
+
+	printf "$(get_msg 'cmd_help_summary_head')\n"
+	print_cmd_summaries
+}
+
+cmd_help_register()
+{
+	register_cmd 'help'
+}
+__init cmd_help_register
diff --git a/src/cmd/install.sh b/src/cmd/install.sh
new file mode 100644
index 0000000..e0bdc4e
--- /dev/null
+++ b/src/cmd/install.sh
@@ -0,0 +1,81 @@
+# "install" command
+#
+# Copyright (C) 2013, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_install_optstring='a:p:m:F'
+
+cmd_install_main()
+{
+	local suite=
+	local chroot=
+	local profile=
+	local foreign=
+	local dev=
+
+	if ! get_options "${@}"; then
+		print_cmd_usage 'install' >&2
+		exit 1
+	fi
+	shift $(($OPTIND - 1))
+
+	if [ ${#} -lt 2 ]; then
+		print_cmd_usage 'install' >&2
+		exit 1
+	fi
+
+	# TODO: Consider making suite optional, getting a default suite from the
+	# profile.
+	suite="${1}"
+	chroot="${2}"
+
+	if [ "x${suite%%:*}" != "x${suite}" ]; then
+		profile="${suite%%:*}"
+		suite="${suite#*:}"
+	else
+		profile='proteanos'
+	fi
+	profile_set "${profile}"
+	suite="$(profile_normalize_suite "${suite}")"
+
+	if [ "x${cmd_install_opt_F+set}" = 'xset' ]; then
+		foreign=true
+	else
+		foreign=false
+	fi
+
+	dev=''
+	if is_block "${chroot}"; then
+		dev="${chroot}"
+		chroot="$(block_mount "${dev}")"
+	fi
+
+	install_system "${cmd_install_opt_m-}" "${suite}" \
+		"${cmd_install_opt_a-}" "${cmd_install_opt_p-}" \
+		"${chroot}" "${foreign}"
+
+	if [ "x${dev}" != 'x' ]; then
+		block_umount "${chroot}"
+	fi
+}
+
+cmd_install_register()
+{
+	register_cmd 'install'
+}
+__init cmd_install_register
diff --git a/src/cmd/installer-pc.sh b/src/cmd/installer-pc.sh
new file mode 100644
index 0000000..dd01506
--- /dev/null
+++ b/src/cmd/installer-pc.sh
@@ -0,0 +1,101 @@
+# "installer-pc" command
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_installer_pc_optstring='a:p:m:'
+
+cmd_installer_pc_main()
+{
+	local suite=
+	local dev=
+	local profile=
+	local root=
+	local b4=
+	local b3=
+	local b2=
+	local b1=
+
+	if ! get_options "${@}"; then
+		print_cmd_usage 'installer-pc' >&2
+		exit 1
+	fi
+	shift $(($OPTIND - 1))
+
+	if [ "x${cmd_installer_pc_opt_a-}" = 'x' ]; then
+		print_cmd_usage 'installer-pc' >&2
+		exit 1
+	fi
+	if [ "x${cmd_installer_pc_opt_p-}" = 'x' ]; then
+		print_cmd_usage 'installer-pc' >&2
+		exit 1
+	fi
+	if [ ${#} -ne 2 ]; then
+		print_cmd_usage 'installer-pc' >&2
+		exit 1
+	fi
+
+	suite="${1}"
+	dev="${2}"
+	check_block "${dev}"
+
+	if [ "x${suite%%:*}" != "x${suite}" ]; then
+		profile="${suite%%:*}"
+		suite="${suite#*:}"
+	else
+		profile='proteanos'
+	fi
+	profile_set "${profile}"
+	suite="$(profile_normalize_suite "${suite}")"
+
+	cmd_installer_pc_make_partition_and_fs "${dev}"
+	root="$(block_mount "${dev}1")"
+
+	install_system "${cmd_installer_pc_opt_m-}" "${suite}" \
+		"${cmd_installer_pc_opt_a-}" "${cmd_installer_pc_opt_p-}" \
+		"${root}" false
+
+	if [ -f "${root}/sbin/lilo" ]; then
+		read b4 b3 b2 b1 <<-EOF
+			$(od -An -tx1 -v -j 440 -N 4 "${dev}")
+			EOF
+		# This ln command won't be needed once lilo 24.1-1 is uploaded.
+		ln "${root}/boot/vmlinuz" "${root}/boot/vmlinuz.old"
+		session_begin "${root}" . : false
+		session_exec install-lilo \
+			"${dev}" "PARTUUID=${b1}${b2}${b3}${b4}-01"
+		session_end
+	fi
+
+	block_umount "${root}"
+}
+
+cmd_installer_pc_make_partition_and_fs()
+{
+	local dev="${1}"
+
+	dd if=/dev/zero of="${dev}" bs=512 count=1
+	printf 'n\np\n1\n\n\nt\n83\na\n1\nw\n' | fdisk "${dev}"
+	mke2fs -t ext4 "${dev}1"
+}
+
+cmd_installer_pc_register()
+{
+	register_cmd 'installer-pc'
+}
+__init cmd_installer_pc_register
diff --git a/src/cmd/local.mk b/src/cmd/local.mk
new file mode 100644
index 0000000..a6dd3bd
--- /dev/null
+++ b/src/cmd/local.mk
@@ -0,0 +1,8 @@
+prokit_SOURCES += \
+	src/cmd/help.sh \
+	src/cmd/version.sh \
+	src/cmd/install.sh \
+	src/cmd/shell.sh \
+	src/cmd/opkg.sh \
+	src/cmd/build.sh \
+	src/cmd/installer-pc.sh
diff --git a/src/cmd/opkg.sh b/src/cmd/opkg.sh
new file mode 100644
index 0000000..e1fc8ce
--- /dev/null
+++ b/src/cmd/opkg.sh
@@ -0,0 +1,112 @@
+# "opkg" command
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_opkg_opks=
+
+cmd_opkg_main()
+{
+	local root=
+	local dev=
+	local first_arg=
+	local install_cmd=
+	local arg=
+	local new_fname=
+
+	if [ ${#} -lt 1 ]; then
+		print_cmd_usage 'opkg' >&2
+		exit 1
+	fi
+
+	root="${1}"
+	shift 1
+
+	dev=''
+	if is_block "${root}"; then
+		dev="${root}"
+		root="$(block_mount "${dev}")"
+	fi
+
+	first_arg=true
+	install_cmd=false
+	cmd_opkg_opks=''
+	for arg in "${@}"; do
+		if ${first_arg}; then
+			set --
+			first_arg=false
+		fi
+		if ${install_cmd}; then
+			case "${arg}" in
+				*.opk|*.ipk|*.deb)
+					if ! [ -e "${arg}" ]; then
+						set -- "${@}" "${arg}"
+						continue
+					fi
+					rand
+					new_fname="/tmp/prokit.${rand_x}.opk"
+					cmd_opkg_opks="$(printf '%s %s\n' \
+						"${cmd_opkg_opks}" \
+						"${root}${new_fname}")"
+					cp "${arg}" "${root}${new_fname}"
+					set -- "${@}" "${new_fname}"
+					;;
+				*)
+					set -- "${@}" "${arg}"
+					;;
+			esac
+		else
+			set -- "${@}" "${arg}"
+			if [ "x${arg}" = 'xinstall' ]; then
+				install_cmd=true
+			fi
+		fi
+	done
+
+	. "${root}/etc/os-release"
+	profile_set "${ID}"
+
+	session_begin "${root}" . cmd_opkg_fini false
+
+	session_exec opkg "${@}"
+
+	cmd_opkg_fini
+	session_end
+
+	if [ "x${dev}" != 'x' ]; then
+		block_umount "${root}"
+	fi
+}
+
+cmd_opkg_fini()
+{
+	case "${cmd_opkg_opks}" in
+		*[!\ ]*)
+			rm -f ${cmd_opkg_opks}
+			# Hack to avoid this code branch if the function is
+			# called again in response to a signal.
+			cmd_opkg_opks=''
+			;;
+	esac
+}
+
+cmd_opkg_register()
+{
+	register_cmd 'opkg'
+}
+__init cmd_opkg_register
diff --git a/src/cmd/shell.sh b/src/cmd/shell.sh
new file mode 100644
index 0000000..468da0f
--- /dev/null
+++ b/src/cmd/shell.sh
@@ -0,0 +1,62 @@
+# "shell" command
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_shell_main()
+{
+	local root=
+	local dev=
+
+	if [ ${#} -lt 1 ]; then
+		print_cmd_usage 'shell' >&2
+		exit 1
+	fi
+
+	root="${1}"
+	shift 1
+
+	dev=''
+	if is_block "${root}"; then
+		dev="${root}"
+		root="$(block_mount "${dev}")"
+	fi
+
+	. "${root}/etc/os-release"
+	profile_set "${ID}"
+
+	session_begin "${root}" . : false
+	if [ ${#} -eq 0 ]; then
+		session_exec /bin/sh
+		printf '\n'
+		info "$(get_msg 'cmd_shell_exiting')"
+	else
+		session_exec "${@}"
+	fi
+	session_end
+
+	if [ "x${dev}" != 'x' ]; then
+		block_umount "${root}"
+	fi
+}
+
+cmd_shell_register()
+{
+	register_cmd 'shell'
+}
+__init cmd_shell_register
diff --git a/src/cmd/version.sh b/src/cmd/version.sh
new file mode 100644
index 0000000..0105f20
--- /dev/null
+++ b/src/cmd/version.sh
@@ -0,0 +1,33 @@
+# "version" command
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+cmd_version_main()
+{
+	printf '%s (%s) %s\n' "${0##*/}" "${PACKAGE_NAME}" "${PACKAGE_VERSION}"
+
+	printf "$(get_msg 'cmd_version_copyright')\n" \
+		'2012, 2013, 2014' 'Patrick "P. J." McDermott'
+}
+
+cmd_version_register()
+{
+	register_cmd 'version'
+}
+__init cmd_version_register
diff --git a/src/control.sh b/src/control.sh
new file mode 100644
index 0000000..b25d00b
--- /dev/null
+++ b/src/control.sh
@@ -0,0 +1,147 @@
+# Functions for parsing control files.
+#
+# Copyright (C) 2012, 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+control_file=
+control_line_nr=
+
+parse_control()
+{
+	local field_cb="${2}"
+	local paragraph_cb="${3}"
+	local req_fields="${4}"
+	local in_paragraph=
+	local line=
+	local para_req_fields=
+	local got_fields=
+	local name=
+	local value=
+
+	control_file="${1}"
+	control_line_nr=0
+
+	in_paragraph='false'
+
+	while IFS='' read -r line; do
+		control_line_nr=$(($control_line_nr + 1))
+		if [ "x$(echo ${line})" = 'x' ]; then
+			# Paragraph end.
+			if ${in_paragraph}; then
+				# The first line is blank to consolidate
+				# initialization code (see heredocument below).
+				in_paragraph='false'
+				if [ "x${name}" != 'x' ]; then
+					if ! "${field_cb}" "${name}" "${value}"
+					then
+						return 0
+					fi
+				fi
+				if ! "${paragraph_cb}"; then
+					return 0
+				fi
+				if [ "x${para_req_fields}" != 'x' ]; then
+					para_req_fields="$(printf "%s$(get_msg \
+						'list_item_separator')" \
+						${para_req_fields})"
+					parse_control_error \
+						'control_missing_fields' \
+						"${para_req_fields}"
+				fi
+			fi
+			para_req_fields="$(printf '%s\n' ${req_fields})"
+			got_fields="${LF}"
+			name=''
+			value=''
+		elif [ "x${line#\#}" != "x${line}" ]; then
+			# Comment.
+			in_paragraph='true'
+		elif [ "x${line# }" = "x${line}" ]; then
+			# "Name: Value" line.
+			in_paragraph='true'
+			if [ "x${name}" != 'x' ]; then
+				if ! "${field_cb}" "${name}" "${value}"; then
+					return 0
+				fi
+			fi
+			name="${line%%:*}"
+			value="${line#*:}"
+			value="${value# }"
+			if [ "x${name}" = 'x' -o "x${name}" = "x${line}" ]; then
+				parse_control_error 'control_bad_nv'
+				continue
+			fi
+			if [ "x${para_req_fields}" != 'x' ]; then
+				# Remove field from list of required fields.
+				para_req_fields="$(printf '%s' "${para_req_fields}" | \
+					grep -Fv "${name}")"
+			fi
+			if [ "x${got_fields%${LF}${name}${LF}*}" != \
+					"x${got_fields}" ]; then
+				# Duplicate field.
+				parse_control_error 'control_duplicate_field' \
+					"${name}"
+			else
+				got_fields="${got_fields}${name}${LF}"
+			fi
+		else
+			# Continuation line.
+			in_paragraph='true'
+			if [ "x${name}" = 'x' ]; then
+				# Expecting a "Name: Value" line.
+				parse_control_error 'control_found_continuation'
+				continue
+			fi
+			value="${value}${LF}${line# }"
+		fi
+	done <<-EOF
+
+		$(cat "${control_file}")
+
+		EOF
+	# The first blank line above triggers the paragraph end code to
+	# consolidate initialization code.
+	# The second blank line above is needed because the command substitution
+	# removes any trailing newlines.
+
+	if [ "x${name}" != 'x' ]; then
+		if ! "${field_cb}" "${name}" "${value}"; then
+			return 0
+		fi
+	fi
+
+	return 0
+}
+
+parse_control_error()
+{
+	local msgid="${1}"
+	local file_info=
+	shift 1
+
+	if [ ${control_line_nr} -eq 0 ]; then
+		file_info="$(printf '%20s:' "${control_file}")"
+	else
+		file_info="$(printf '%20s(l%d):' "${control_file}" \
+			"${control_line_nr}")"
+	fi
+
+	warn "${file_info} $(get_msg "${msgid}")" "${@}"
+
+	return 0
+}
diff --git a/src/deps.sh b/src/deps.sh
new file mode 100644
index 0000000..862caff
--- /dev/null
+++ b/src/deps.sh
@@ -0,0 +1,156 @@
+# Functions for parsing dependency field values
+#
+# Copyright (C) 2012, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+parse_dep()
+{
+	local dep="${1}"
+	local host_arch="${2}"
+	local host_plat="${3}"
+	local pkgarchqual=
+	local pkg=
+	local archqual=
+	local relver=
+	local rel=
+	local ver=
+	local arches=
+	local plats=
+
+	dep="$(printf '%s\n' "${dep}" | sed -n '
+		H;                        # Store each input line in hold space.
+		${                        # On the last line:
+		  g;                      # Restore everything to pattern space.
+		  s/[\t\n]/ /g;           # Replace tabs & newlines with spaces.
+		  s/ *\([(\[<]\) */ \1/g; # One space before "(", "[", and "<".
+		  s/ *\([)\]>]\) */\1 /g; # One space after "(", "[", and "<".
+		  s/ *\(<[<=]\) */\1 /g;  # One space after "<<" and "<=".
+		  s/ *\(>[>=]\) */\1 /g;  # One space after ">>" and ">=".
+		  s/ *\(=\) */\1 /g;      # One space after "=".
+		  s/^ *//;                # Remove leading spaces.
+		  s/ *$//;                # Remove trailing spaces.
+		  s/  */ /g;              # Remove duplicate spaces.
+		  p;                      # Print the pattern space.
+		};                        # End.
+		')"
+
+	# dep is now of the form:
+	# pkg[:archqual] [(rel ver)] [\[arches\]] [<plats>]
+
+	pkgarchqual="${dep%% *}"
+	dep=" ${dep#* }"
+	pkg="${pkgarchqual%:*}"
+	if [ "x${pkg}" != "x${pkgarchqual}" ]; then
+		archqual="${pkgarchqual##*:}"
+	fi
+
+	if [ "x${dep# (*)}" != "x${dep}" ]; then
+		relver="${dep# (}"
+		relver="${relver%%)*}"
+		dep="${dep# (*)}"
+		rel="${relver% *}"
+		ver="${relver##* }"
+	fi
+
+	if [ "x${dep# \[*\]}" != "x${dep}" ]; then
+		arches="${dep# \[}"
+		arches="${arches%%\]*}"
+		dep="${dep# \[*\]}"
+	fi
+
+	if [ "x${dep# <*>}" != "x${dep}" ]; then
+		plats="${dep# <}"
+		plats="${plats%%>*}"
+		dep="${dep# <*>}"
+	fi
+
+	if [ "x${host_arch}" != 'x' ] && ! arch_is_concerned \
+			"${host_arch}" "${arches}"; then
+		return 0
+	fi
+	if [ "x${host_plat}" != 'x' ] && ! plat_is_concerned \
+			"${host_plat}" "${plats}"; then
+		return 0
+	fi
+
+	printf '%s' "${pkg}"
+	[ "x${archqual}" != 'x' ] && printf ':%s' "${archqual}"
+	[ "x${ver}" != 'x' ] && printf ' (%s %s)' "${rel}" "${ver}"
+	[ "x${host_arch}" = 'x' ] && [ "x${arches}" != 'x' ] && \
+		printf ' [%s]' "${arches}"
+	[ "x${host_plat}" = 'x' ] && [ "x${plats}" != 'x' ] && \
+		printf ' <%s>' "${plats}"
+	printf '\n'
+
+	return 0
+}
+
+reduce_deps()
+{
+	local deps="${1}"
+	local union="${2}"
+	local host_arch="${3}"
+	local host_plat="${4}"
+	local dep_and=
+	local dep_or=
+	local dep_list=
+	local dep_or_list=
+	local dep=
+
+	dep_list=''
+	IFS=','
+	for dep_and in ${deps}; do
+		unset IFS
+		if ! ${union}; then
+			dep_or_list=''
+			IFS='|'
+			for dep_or in ${dep_and}; do
+				unset IFS
+				dep="$(parse_dep "${dep_or}" \
+					"${host_arch}" "${host_plat}")"
+				if [ "x${dep}" != 'x' ]; then
+					if [ "x${dep_or_list}" != 'x' ]; then
+						dep_or_list="${dep_or_list} | "
+					fi
+					dep_or_list="${dep_or_list}${dep}"
+				fi
+			done
+			unset IFS
+			if [ "x${dep_or_list}" != 'x' ]; then
+				if [ "x${dep_list}" != 'x' ]; then
+					dep_list="${dep_list}, "
+				fi
+				dep_list="${dep_list}${dep_or_list}"
+			fi
+		else
+			dep="$(parse_dep "${dep_and}" \
+				"${host_arch}" "${host_plat}")"
+			if [ "x${dep}" != 'x' ]; then
+				if [ "x${dep_list}" != 'x' ]; then
+					dep_list="${dep_list}, "
+				fi
+				dep_list="${dep_list}${dep}"
+			fi
+		fi
+	done
+	unset IFS
+
+	printf '%s\n' "${dep_list}"
+
+	return 0
+}
diff --git a/src/dir.sh b/src/dir.sh
new file mode 100644
index 0000000..338d8fe
--- /dev/null
+++ b/src/dir.sh
@@ -0,0 +1,56 @@
+# Miscellaneous directory-related functions
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+dir_is_empty()
+{
+	local dir="${1}"
+	local ret=
+	local dirent=
+	local exclude=
+	local exclusion=
+	shift 1
+
+	ret=0
+
+	# Patterns to match all dirents except "." and "..":
+	#   *      dirents whose names don't start with "."
+	#   .[!.]  dirents whose names start with ".", are two characters long,
+	#          and aren't ".."
+	#   .??*   dirents whose names start with "." and are three or more
+	#          characters long
+	for dirent in "${dir}/"* "${dir}/".[!.] "${dir}/".[!.] "${dir}/".??*; do
+		if ! [ -e "${dirent}" ]; then
+			continue
+		fi
+		exclude=false
+		for exclusion in "${@}"; do
+			if [ "x${dirent##*/}" = "x${exclusion}" ]; then
+				exclude=true
+				break
+			fi
+		done
+		if ! ${exclude}; then
+			ret=1
+			break
+		fi
+	done
+
+	return ${ret}
+}
diff --git a/src/fd.sh b/src/fd.sh
new file mode 100644
index 0000000..0d5a50e
--- /dev/null
+++ b/src/fd.sh
@@ -0,0 +1,92 @@
+# Functions for opening and closing file descriptors
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+_FD_MIN=3
+# Shells and the file descriptors they reserve for the user:
+#   * Debian Almquist Shell
+#     - The shell doesn't understand any file descriptor greater than 9.
+#     - File descriptors starting at 10 are used for I/O redirection.
+#   * BusyBox ash
+#     - File descriptors starting at 10 are used for job control and I/O
+#       redirection.
+#   * GNU Bash:
+#     - GNU Readline uses file descriptor 255 in interactive shells.
+#     - File descriptors starting at 10 are used for I/O redirection.
+#   * MirOS Korn Shell
+#     - File descriptors starting at either 10 or 24 are used for the shell's
+#       tty_fd and shl_dbg_fd.
+#   * Solaris ksh
+#     - The shell doesn't understand any file descriptor greater than 9.
+_FD_MAX=9
+
+FD=
+
+fopen()
+{
+	local path="${1}"
+	local mode="${2}"
+	local i=
+	local fd=
+
+	case "${mode}" in
+		'r')  mode='<' ;;
+		'w')  mode='>' ;;
+		'a')  mode='>>';;
+		'rw') mode='<>';;
+		*) return 125;;
+	esac
+
+	# Find first available file descriptor.
+	i=${_FD_MIN}
+	while [ ${i} -le ${_FD_MAX} ]; do
+		if [ "x$(eval echo "\${_fd_${i}+set}")" != 'xset' ]; then
+			fd=${i}
+			break
+		fi
+		i=$(($i + 1))
+	done
+	if [ "x${fd:+set}" != 'xset' ]; then
+		error 2 "$(get_msg 'emfile')"
+		return
+	fi
+
+	if eval "exec ${fd}${mode}'${path}'"; then
+		eval "_fd_${fd}='${mode}${path}'"
+		FD="${fd}"
+		return 0
+	else
+		error 2 "$(get_msg 'cant_fopen')"
+	fi
+}
+
+fclose()
+{
+	local fd="${1}"
+
+	# Make sure the file descriptor is open.
+	if [ "x$(eval echo "\${_fd_${fd}+set}")" != 'xset' ]; then
+		error 2 "$(get_msg 'ebadf')"
+	fi
+
+	eval "exec ${fd}>&-"
+	unset "_fd_${fd}"
+
+	return 0
+}
diff --git a/src/feed.sh b/src/feed.sh
new file mode 100644
index 0000000..4288c2a
--- /dev/null
+++ b/src/feed.sh
@@ -0,0 +1,137 @@
+# Functions for handling feed index files
+#
+# Copyright (C) 2013, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+feed_dep_fields=
+feed_pkg_cb=
+feed_deps_cb=
+feed_fname_cb=
+feed_md5sum_cb=
+feed_sha256sum_cb=
+feed_pkgs=
+feed_pkg_include=
+feed_pkg=
+feed_deps=
+
+feed_download()
+{
+	local feed_index="${1}"
+	local use_gzip="${2}"
+	local gzip=
+
+	if ${use_gzip}; then
+		gzip=gunzip
+	else
+		gzip=cat
+	fi
+
+	wget -q -O - "${feed_index}" | ${gzip}
+
+	return 0
+}
+
+feed_find_pkgs()
+{
+	local feed_idx="${1}"
+	local dep_fields="${2}"
+	local pkg_cb="${3}"
+	local deps_cb="${4}"
+	local fname_cb="${5}"
+	local md5sum_cb="${6}"
+	local sha256sum_cb="${7}"
+
+	feed_dep_fields=" $(printf '%s ' ${dep_fields} | tr 'A-Z' 'a-z')"
+	feed_pkg_cb="${pkg_cb}"
+	feed_deps_cb="${deps_cb}"
+	feed_fname_cb="${fname_cb}"
+	feed_md5sum_cb="${md5sum_cb}"
+	feed_sha256sum_cb="${sha256sum_cb}"
+
+	feed_pkgs=''
+	feed_pkg_include='false'
+	feed_pkg=''
+	feed_deps=''
+
+	parse_control "${feed_idx}" feed_field_cb feed_para_cb 'Package'
+
+	printf '%s\n' "${feed_pkgs# }"
+
+	return 0
+}
+
+feed_field_cb()
+{
+	local name="${1}"
+	local value="${2}"
+
+	name="$(printf '%s\n' "${name}" | tr 'A-Z' 'a-z')"
+
+	if [ "x${name}" = 'xpackage' ]; then
+		feed_pkg="${value}"
+	elif [ "x${name}" = 'xfilename' ]; then
+		${feed_fname_cb} "${feed_pkg}" "${value}"
+	elif [ "x${name}" = 'xmd5sum' ]; then
+		${feed_md5sum_cb} "${feed_pkg}" "${value}"
+	elif [ "x${name}" = 'xsha256sum' ]; then
+		${feed_sha256sum_cb} "${feed_pkg}" "${value}"
+	elif [ "x${feed_dep_fields#* ${name} }" != "x${feed_dep_fields}" ]; then
+		feed_deps="${feed_deps}${value}, "
+	fi
+
+	if ${feed_pkg_cb} ${name} ${value}; then
+		feed_pkg_include='true'
+	fi
+
+	return 0
+}
+
+feed_para_cb()
+{
+	local new_deps=
+	local dep=
+
+	if ${feed_pkg_include}; then
+		feed_pkgs="${feed_pkgs} ${feed_pkg}"
+	fi
+
+	new_deps=''
+	IFS=','
+	for dep in ${feed_deps%, }; do
+		unset IFS
+		# Trim off versions and disjunctions.
+		dep="${dep%%(*}"
+		dep="${dep%%|*}"
+		# Trim whitespace.
+		dep="$(printf '%s\n' "${dep}" | sed 's/^ *//; s/ *$//')"
+		# In practice, this would suffice for control files generated by
+		# opkbuild:
+		#     dep="${dep#[ ${HT}${LF}]}"
+		#     dep="${dep%[ ${HT}${LF}]}"
+		new_deps="${new_deps} ${dep}"
+	done
+	unset IFS
+
+	${feed_deps_cb} "${feed_pkg}" "${new_deps# }"
+
+	feed_pkg_include='false'
+	feed_pkg=''
+	feed_deps=''
+
+	return 0
+}
diff --git a/src/getopt.sh b/src/getopt.sh
new file mode 100644
index 0000000..07769e7
--- /dev/null
+++ b/src/getopt.sh
@@ -0,0 +1,52 @@
+# Functions for parsing command-line options
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+get_options()
+{
+	local optstring=
+	local prefix=
+	local opt=
+
+	if [ "x${running_cmd_clean}" = 'x' ]; then
+		optstring="${OPTSTRING}"
+		prefix='opt_'
+	else
+		eval "optstring=\"\${cmd_${running_cmd_clean}_optstring}\""
+		prefix="cmd_${running_cmd_clean}_opt_"
+	fi
+
+	unset OPTARG
+	while getopts "${optstring}" opt; do
+		if [ "x${opt}" = 'x?' ]; then
+			return 1
+		fi
+		case "${optstring}" in
+			*"${opt}:"*)
+				eval "${prefix}${opt}=\"\${OPTARG}\""
+				;;
+			*)
+				eval "${prefix}${opt}=true"
+				;;
+		esac
+		unset OPTARG
+	done
+
+	return 0
+}
diff --git a/src/install.sh b/src/install.sh
new file mode 100644
index 0000000..e1e93df
--- /dev/null
+++ b/src/install.sh
@@ -0,0 +1,266 @@
+# Functions for installing systems
+#
+# Copyright (C) 2013, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+install_deps=
+install_fnames=
+install_md5sums=
+install_sha256sums=
+install_feed_url=
+
+install_system()
+{
+	local mirror="${1}"
+	local suite="${2}"
+	local arch="${3}"
+	local plat="${4}"
+	local chroot="${5}"
+	local foreign="${6}"
+
+	if [ "x${arch}" = 'x' ]; then
+		arch="$(profile_detect_arch)"
+	fi
+	if [ "x${plat}" = 'x' ]; then
+		plat="$(profile_default_plat)"
+	fi
+	if [ "x${mirror}" = 'x' ]; then
+		mirror="$(profile_select_mirror)"
+	fi
+
+	if ! profile_validate_archplat "${mirror}" "${arch}" "${plat}" \
+			"${suite}"; then
+		error 2 "$(get_msg 'install_bad_archplat')" \
+			"${arch}" "${plat}"
+	fi
+
+	info "$(get_msg 'install_selected_arch')" "${arch}"
+	info "$(get_msg 'install_selected_plat')" "${plat}"
+	info "$(get_msg 'install_selected_mirror')" "${mirror}"
+
+	info "$(get_msg 'install_setting_up_chroot')"
+	if [ -d "${chroot}" ] && ! dir_is_empty "${chroot}" 'lost+found'; then
+		error 2 "$(get_msg 'install_chroot_dir_exists')" "${chroot}"
+	fi
+	if ! mkdir -p "${chroot}/.prokit" "${chroot}/prokit"; then
+		error 2 "$(get_msg 'install_mkdir_chroot_fail')" "${chroot}"
+	fi
+	>"${chroot}/prokit/installing"
+
+	info "$(get_msg 'install_find_pkgs')"
+	install_find_pkgs "${mirror}" "${suite}" "${arch}" "${plat}" \
+		"${chroot}"
+	install_get_pkgs "${chroot}"
+
+	info "$(get_msg 'install_configuring')"
+	if ! ${foreign}; then
+		profile_configure_system_native "${chroot}" "${arch}" "${plat}"
+	else
+		profile_configure_system_foreign "${chroot}" "${arch}" "${plat}"
+	fi
+
+	rm "${chroot}/prokit/installing"
+}
+
+install_find_pkgs()
+{
+	local mirror="${1}"
+	local suite="${2}"
+	local arch="${3}"
+	local plat="${4}"
+	local chroot="${5}"
+	local opkg_conf_fd=
+	local pkgs_fd=
+	local opt=
+	local feed_idx=
+	local feed=
+	local gzip=
+	local pkgs=
+
+	mkdir -p "${chroot}/etc/opkg" "${chroot}/var/lib/opkg/lists"
+	fopen "${chroot}/etc/opkg/opkg.conf" 'w'
+	opkg_conf_fd=${FD}
+
+	install_deps=
+	install_fnames=
+	install_md5sums=
+	install_sha256sums=
+
+	fopen "${chroot}/.prokit/packages" 'w'
+	pkgs_fd=${FD}
+
+	while read -r opt feed_idx feed; do
+		case "${opt}" in
+			'src') gzip=false;;
+			'src/gz') gzip=true;;
+			*) continue;;
+		esac
+		printf '%s %s %s\n' "${opt}" "${feed_idx}" \
+			"${feed%/Packages*}"  >&${opkg_conf_fd}
+		feed_download "${feed}" ${gzip} \
+			>"${chroot}/var/lib/opkg/lists/${feed_idx}"
+		install_feed_url="${feed%/*}"
+		feed_find_pkgs "${chroot}/var/lib/opkg/lists/${feed_idx}" \
+			"$(profile_dep_fields)" profile_include_pkg \
+			install_deps_cb install_fname_cb \
+			install_md5sum_cb install_sha256sum_cb \
+			>&${pkgs_fd}
+	done <<-EOF
+		$(profile_feeds "${mirror}" "${arch}" "${plat}" "${suite}")
+		EOF
+
+	printf '\ndest root /\n' >&${opkg_conf_fd}
+	printf 'arch %s 1\n' 'all' "${arch}" 'src' >&${opkg_conf_fd}
+	fclose ${opkg_conf_fd}
+	fclose ${pkgs_fd}
+
+	pkgs="$(resolve_deps "$(cat "${chroot}/.prokit/packages")" \
+		"${install_deps}" | xargs printf '%s\n' | sort -u)"
+	printf '%s\n' "${pkgs}" >"${chroot}/.prokit/packages"
+}
+
+install_deps_cb()
+{
+	local pkg="${1}"
+	local deps="${2}"
+
+	install_deps="${install_deps}${pkg}: ${deps}${LF}"
+}
+
+install_fname_cb()
+{
+	local pkg="${1}"
+	local fname="${2}"
+
+	install_fnames="$(printf '%s\n%s %s/%s' "${install_fnames}" \
+		"${pkg}" "${install_feed_url}" "${fname}")"
+}
+
+install_md5sum_cb()
+{
+	local pkg="${1}"
+	local md5sum="${2}"
+
+	install_md5sums="$(printf '%s\n%s %s' "${install_md5sums}" \
+		"${pkg}" "${md5sum}")"
+}
+
+install_sha256sum_cb()
+{
+	local pkg="${1}"
+	local sha256sum="${2}"
+
+	install_sha256sums="$(printf '%s\n%s %s' \
+		"${install_sha256sums}" "${pkg}" "${sha256sum}")"
+}
+
+install_get_pkgs()
+{
+	local chroot="${1}"
+	local status_fd=
+	local pkg=
+	local fname=
+	local md5sum=
+	local sha256sum=
+	local file=
+	local control=
+	local field=
+	local printed=
+
+	mkdir -p "${chroot}/var/cache/opkg/archives" "${chroot}/tmp/opkg" \
+		"${chroot}/var/lib/opkg/info"
+
+	fopen "${chroot}/var/lib/opkg/status" 'w'
+	status_fd=${FD}
+
+	for pkg in $(cat "${chroot}/.prokit/packages"); do
+		info "$(get_msg 'install_downloading_pkg')" "${pkg}"
+		fname="$(printf '%s\n' "${install_fnames}" | \
+			sed -n "s/^${pkg} //p")"
+		md5sum="$(printf '%s\n' "${install_md5sums}" | \
+			sed -n "s/^${pkg} //p")"
+		sha256sum="$(printf '%s\n' "${install_sha256sums}" | \
+			sed -n "s/^${pkg} //p")"
+		wget -q -O "${chroot}/var/cache/opkg/archives/${fname##*/}" \
+			"${fname}" || \
+			error 2 "$(get_msg 'install_downloading_pkg_fail')"
+		fname="var/cache/opkg/archives/${fname##*/}"
+		if [ "x${md5sum}" != 'x' ]; then
+			printf '%s  %s\n' \
+				"${md5sum}" "${chroot}/${fname}" | \
+				md5sum -c >/dev/null 2>&1 || \
+				error 2 "$(get_msg 'install_checksum_fail')"
+		fi
+		if [ "x${sha256sum}" != 'x' ]; then
+			printf '%s  %s\n' \
+				"${sha256sum}" "${chroot}/${fname}" | \
+				sha256sum -c >/dev/null 2>&1 || \
+				error 2 "$(get_msg 'install_checksum_fail')"
+		fi
+
+		info "$(get_msg 'install_unpacking_pkg')" "${pkg}"
+		mkdir "${chroot}/tmp/opkg/${pkg}"
+		(
+			cd "${chroot}"
+			tar -xzOf "${fname}" data.tar.gz \
+				>"tmp/opkg/${pkg}/data.tar.gz"
+			tar -xzf "tmp/opkg/${pkg}/data.tar.gz"
+			cd "tmp/opkg/${pkg}"
+			tar -xzOf "../../../${fname}" control.tar.gz | \
+				tar -xz
+		)
+		tar -tzf "${chroot}/tmp/opkg/${pkg}/data.tar.gz" | \
+			sed 's/^\.//' >"${chroot}/var/lib/opkg/info/${pkg}.list"
+		rm -f "${chroot}/tmp/opkg/${pkg}/data.tar.gz"
+		for file in "${chroot}/tmp/opkg/${pkg}/"*; do
+			mv "${file}" \
+				"${chroot}/var/lib/opkg/info/${pkg}.${file##*/}"
+		done
+		rmdir "${chroot}/tmp/opkg/${pkg}"
+
+		# Write status file.
+		control="${chroot}/var/lib/opkg/info/${pkg}.control"
+		for field in Package Version Depends Recommends Suggests \
+				Provides Replaces Conflicts; do
+			grep "^${field}: " "${control}" >&${status_fd}
+		done
+		printf 'Status: install ok unpacked\n' >&${status_fd}
+		for field in Essential Architecture; do
+			grep "^${field}: " "${control}" >&${status_fd}
+		done
+		if [ -r "${chroot}/var/lib/opkg/info/${pkg}.conffiles" ]; then
+			printed=false
+			while read -r file; do
+				${printed} || printf 'Conffiles:\n' \
+					>&${status_fd}
+				printf ' %s %s\n' "${file}" "$(md5sum \
+					"${chroot}/${file}" | cut -d' ' -f1)" \
+					>&${status_fd}
+				printed=true
+			done <"${chroot}/var/lib/opkg/info/${pkg}.conffiles"
+		fi
+		printf 'Installed-Time: %s\n\n' "$(date '+%s')" >&${status_fd}
+
+		rm -f "${chroot}/${fname}"
+	done
+
+	rm "${chroot}/.prokit/packages"
+	rmdir "${chroot}/.prokit"
+
+	fclose ${status_fd}
+}
diff --git a/src/local.mk b/src/local.mk
index d989dbf..dae4309 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -1,2 +1,27 @@
-bin_sources = \
-	src/prokit.sh
+prokit_SOURCES += \
+	src/main.sh \
+	src/output.sh \
+	src/locale.sh \
+	src/getopt.sh \
+	src/fd.sh \
+	src/dir.sh \
+	src/vardata.sh \
+	src/archplat.sh \
+	src/deps.sh \
+	src/substvars.sh \
+	src/control.sh \
+	src/feed.sh \
+	src/pkg.sh \
+	src/mutex.sh \
+	src/session.sh \
+	src/block.sh \
+	src/opkg.sh \
+	src/rand.sh \
+	src/cmd.sh \
+	src/profile.sh \
+	src/package.sh \
+	src/install.sh
+
+include $(top_srcdir)/src/cmd/local.mk
+include $(top_srcdir)/src/profile/local.mk
+include $(top_srcdir)/src/package/local.mk
diff --git a/src/locale.sh b/src/locale.sh
new file mode 100644
index 0000000..76d2d9b
--- /dev/null
+++ b/src/locale.sh
@@ -0,0 +1,84 @@
+# Locale functions
+#
+# Copyright (C) 2012, 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+DEFAULT_LOCALE='en_US'
+
+load_locale()
+{
+	local localedir=
+
+	# Make sure LC_MESSAGES is set.
+	if [ "x${LC_MESSAGES+set}" != 'xset' ]; then
+		if [ "x${LC_ALL+set}" = 'xset' ]; then
+			LC_MESSAGES="${LC_ALL}"
+		elif [ "x${LANG+set}" = 'xset' ]; then
+			LC_MESSAGES="${LANG}"
+		else
+			LC_MESSAGES="${DEFAULT_LOCALE}"
+		fi
+	fi
+
+	if ${in_place}; then
+		localedir="${builddir}/locale"
+	else
+		localedir="${LOCALEDIR}"
+	fi
+
+	# Try to load the locale.
+	if ! _try_load_locale "${localedir}" \
+			"${LC_MESSAGES%.*}"; then
+		if ! _try_load_locale "${localedir}" \
+				"${LC_MESSAGES%_*}"; then
+			if ! _try_load_locale "${localedir}" \
+					"${DEFAULT_LOCALE}"; then
+				warn 'Cannot load locale'
+				return 1
+			fi
+		fi
+	fi
+
+	return 0
+}
+
+get_msg()
+{
+	local msgid="${1}"
+
+	eval "printf '%s' \"\${msg_${TEXTDOMAIN}_${msgid}}\""
+
+	return 0
+}
+
+_try_load_locale()
+{
+	local localedir="${1}"
+	local locale="${2}"
+	local ms=
+
+	for ms in "${localedir}/${locale}/LC_MESSAGES/${TEXTDOMAIN}.ms" \
+			"${localedir}/${locale}.ms"; do
+		if [ -f "${ms}" ]; then
+			. "${ms}"
+			return 0
+		fi
+	done
+
+	return 1
+}
diff --git a/src/prokit.sh b/src/main.sh
index 5cfdb53..d0ca8f7 100644
--- a/src/prokit.sh
+++ b/src/main.sh
@@ -1,5 +1,3 @@
-#!@SH@
-#
 # Main program file
 #
 # Copyright (C) 2013, 2014  Patrick "P. J." McDermott
@@ -26,52 +24,24 @@ set -u
 HT='	'
 LF='
 '
-PACKAGE_NAME='@PACKAGE_NAME@'
-PACKAGE_VERSION='@PACKAGE_VERSION@'
-PKGDATADIR='@pkgdatadir@'
 OPTSTRING='hV'
 
 if [ -f "${0%/*}/../.builddirstamp" ]; then
 	in_place=true
 	builddir="${0%/*}/.."
+elif [ -f "${0%/*}/.builddirstamp" ]; then
+	in_place=true
+	builddir="${0%/*}"
 else
 	in_place=false
 	builddir=''
 fi
 
-# use() must be defined inline so it can be used to load other modules.
-use()
-{
-	local module="${1}"
-	local dir=
-
-	if ${in_place}; then
-		dir="${builddir}/lib"
-	else
-		dir="${PKGDATADIR}"
-	fi
-
-	if [ -f "${dir}/${module}.sm" ]; then
-		. "${dir}/${module}.sm"
-	else
-		printf '%s: Error: Failed to load module "%s": %s\n' \
-			"${0##*/}" "${module}" 'no such file or directory' >&2
-		exit 2
-	fi
-}
-
-use locale
-use cmd
-use vardata
-use getopt
-use rand
-
 main()
 {
 	local cmd=
 
 	load_locale
-	load_cmds
 	init_vardata
 
 	if ! get_options "${@}"; then
@@ -121,5 +91,3 @@ check_uid()
 
 	return 0
 }
-
-main "${@}"
diff --git a/src/mutex.sh b/src/mutex.sh
new file mode 100644
index 0000000..cd4a365
--- /dev/null
+++ b/src/mutex.sh
@@ -0,0 +1,54 @@
+# Functions for locking and unlocking mutex objects
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+mutex_trylock()
+{
+	local mutex="${1}"
+
+	(set -C; printf '%d\n' "${$}" >"${mutex}") 2>/dev/null
+}
+
+mutex_timedlock()
+{
+	local mutex="${1}"
+	local timeout="${2}"
+
+	while ! mutex_trylock "${mutex}"; do
+		[ ${timeout} -eq 0 ] && return 1
+		timeout=$(($timeout - 1))
+		sleep 1
+	done
+
+	return 0
+}
+
+mutex_unlock()
+{
+	local mutex="${1}"
+
+	rm "${mutex}"
+}
+
+mutex_is_unlockable()
+{
+	local mutex="${1}"
+
+	[ "x$(cat "${mutex}" 2>/dev/null)" = "x${$}" ]
+}
diff --git a/src/opkg.sh b/src/opkg.sh
new file mode 100644
index 0000000..9e5c3c4
--- /dev/null
+++ b/src/opkg.sh
@@ -0,0 +1,29 @@
+# Functions for running the package manager
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+opkg_install_all()
+{
+	local root="${1}"
+
+	session_begin "${root}" . : true
+	session_exec /bin/sh -c \
+		'opkg install $(opkg list-installed | cut -d " " -f 1)'
+	session_end
+}
diff --git a/src/output.sh b/src/output.sh
new file mode 100644
index 0000000..62d2095
--- /dev/null
+++ b/src/output.sh
@@ -0,0 +1,56 @@
+# Functions for printing messages
+#
+# Copyright (C) 2013  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+error()
+{
+	local status=${1}
+	local fmt="${2}"
+	shift 2
+
+	printf '%s: Error: ' "${0##*/}" >&2
+	printf "${fmt}\n" "${@}" >&2
+
+	# In a subshell, this will have no effect, so the shell's exit status
+	# will be 128+SIGINT.  Meh.
+	exit_status=${status}
+	kill -s INT ${$}
+}
+
+warn()
+{
+	local fmt="${1}"
+	shift 1
+
+	printf '%s: Warning: ' "${0##*/}" >&2
+	printf "${fmt}\n" "${@}" >&2
+
+	return 0
+}
+
+info()
+{
+	local fmt="${1}"
+	shift 1
+
+	printf '%s: ' "${0##*/}" >&2
+	printf "${fmt}\n" "${@}" >&2
+
+	return 0
+}
diff --git a/src/package.sh b/src/package.sh
new file mode 100644
index 0000000..3175202
--- /dev/null
+++ b/src/package.sh
@@ -0,0 +1,62 @@
+# Interface for handling source package metadata
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+package_dir=
+package_format=
+
+package_init()
+{
+	local dir="${1}"
+
+	package_dir="${dir}"
+
+	package_format=''
+	if [ -r "${package_dir}/format" ]; then
+		case "$(cat "${package_dir}/format")" in
+			2.*)
+				package_format=2
+				;;
+		esac
+	fi
+
+	if [ "x${package_format}" = 'x' ]; then
+		error 2 "$(get_msg 'package_format_unknown')"
+	fi
+
+	use "package/${package_format}"
+
+	return 0
+}
+
+package_get_build_deps()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	"package_${package_format}_get_build_deps" "${arch}" "${plat}"
+}
+
+package_set_substvars()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	"package_${package_format}_set_substvars" "${arch}" "${plat}"
+}
diff --git a/src/package/2.sh b/src/package/2.sh
new file mode 100644
index 0000000..fc4c77d
--- /dev/null
+++ b/src/package/2.sh
@@ -0,0 +1,77 @@
+# Functions for handling metadata in SPF 2.0 packages
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+package_2_build_deps=
+
+package_2_get_build_deps()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	package_2_build_deps=''
+	parse_control "${package_dir}/control" \
+		package_2_build_deps_field_cb false ''
+
+	substvars "$(reduce_deps "${package_2_build_deps}" false \
+		"${arch}" "${plat}")"
+
+	return 0
+}
+
+package_2_build_deps_field_cb()
+{
+	local name="${1}"
+	local value="${2}"
+
+	name="$(printf '%s\n' "${name}" | tr 'A-Z' 'a-z')"
+
+	if [ "x${name}" = 'xbuild-depends' ]; then
+		package_2_build_deps="${value}"
+		return 1
+	fi
+
+	return 0
+}
+
+package_2_set_substvars()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	if [ -f "${package_dir}/substvars" ]; then
+		parse_control "${package_dir}/substvars" \
+			package_2_substvar_cb false ''
+	fi
+
+	set_substvar 'Host-Arch' "${arch}"
+	set_substvar 'Host-Plat' "${plat}"
+
+	return 0
+}
+
+package_2_substvar_cb()
+{
+	local name="${1}"
+	local value="${2}"
+
+	set_substvar "${name}" "${value}"
+
+	return 0
+}
diff --git a/src/package/local.mk b/src/package/local.mk
new file mode 100644
index 0000000..9ec2158
--- /dev/null
+++ b/src/package/local.mk
@@ -0,0 +1,2 @@
+prokit_SOURCES += \
+	src/package/2.sh
diff --git a/src/pkg.sh b/src/pkg.sh
new file mode 100644
index 0000000..ee4aa25
--- /dev/null
+++ b/src/pkg.sh
@@ -0,0 +1,51 @@
+# Functions for handling packages and their dependencies
+#
+# Copyright (C) 2013, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+resolve_deps()
+{
+	local new_pkgs="${1}"
+	local deps="${2}"
+	local all_deps=
+	local new_deps=
+	local pkg=
+
+	all_deps=''
+	new_pkgs="${new_pkgs} "
+	while [ "x${new_pkgs}" != 'x' ]; do
+		all_deps="${all_deps}${new_pkgs}"
+		new_deps=''
+		for pkg in ${new_pkgs}; do
+			case "${pkg}" in
+				*[!a-z0-9+.-]*) continue;;
+			esac
+			new_deps="${new_deps} $(printf '%s' "${deps}" | \
+				sed -n "s/^${pkg}: *//p")"
+		done
+		new_deps="$(printf '%s\n' ${new_deps} | sort -u)"
+		new_pkgs=''
+		for pkg in ${new_deps}; do
+			if [ "x${all_deps# ${pkg} }" = "x${all_deps}" ]; then
+				new_pkgs="${new_pkgs}${pkg} "
+			fi
+		done
+	done
+
+	printf '%s\n' "${all_deps% }"
+}
diff --git a/src/profile.sh b/src/profile.sh
new file mode 100644
index 0000000..f64a0d8
--- /dev/null
+++ b/src/profile.sh
@@ -0,0 +1,165 @@
+# Profile-related functions
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+profiles=' '
+profile=
+
+register_profile()
+{
+	local profile="${1}"
+	shift 1
+
+	profiles="${profiles}${profile} "
+	return 0
+}
+
+is_profile()
+{
+	local prof="${1}"
+
+	[ "x${profiles# ${prof} }" != "x${profiles}" ]
+}
+
+profile_set()
+{
+	local prof="${1}"
+
+	if is_profile "${prof}"; then
+		profile="${prof}"
+		use "profile/${profile}"
+	else
+		error 1 "$(get_msg 'profile_not_found')" "${prof}"
+	fi
+
+	return 0
+}
+
+profile_normalize_suite()
+{
+	local suite="${1}"
+
+	"prof_${profile}_normalize_suite" "${suite}"
+}
+
+profile_detect_arch()
+{
+	"prof_${profile}_detect_arch"
+}
+
+profile_default_plat()
+{
+	"prof_${profile}_default_plat"
+}
+
+profile_select_mirror()
+{
+	"prof_${profile}_select_mirror"
+}
+
+profile_validate_archplat()
+{
+	local mirror="${1}"
+	local arch="${2}"
+	local plat="${3}"
+	local suite="${4}"
+
+	"prof_${profile}_validate_archplat" "${mirror}" "${arch}" "${plat}" \
+		"${suite}"
+}
+
+profile_feeds()
+{
+	local mirror="${1}"
+	local arch="${2}"
+	local plat="${3}"
+	local suite="${4}"
+
+	"prof_${profile}_feeds" "${mirror}" "${arch}" "${plat}" "${suite}"
+}
+
+profile_dep_fields()
+{
+	"prof_${profile}_dep_fields"
+}
+
+profile_include_pkg()
+{
+	local name="${1}"
+	local value="${2}"
+
+	"prof_${profile}_include_pkg" "${name}" "${value}"
+}
+
+profile_get_fstab()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	"prof_${profile}_get_fstab" "${arch}" "${plat}"
+}
+
+profile_file_systems_mounted()
+{
+	local root="${1}"
+	local arch="${1}"
+	local plat="${2}"
+
+	"prof_${profile}_file_systems_mounted" "${root}" "${arch}" "${plat}"
+}
+
+profile_bind_mount()
+{
+	local arch="${1}"
+	local plat="${2}"
+	local olddir="${3}"
+	local newdir="${4}"
+
+	"prof_${profile}_bind_mount" "${arch}" "${plat}" \
+		"${olddir}" "${newdir}"
+}
+
+profile_bind_umount()
+{
+	local arch="${1}"
+	local plat="${2}"
+	local olddir="${3}"
+	local newdir="${4}"
+
+	"prof_${profile}_bind_umount" "${arch}" "${plat}" \
+		"${olddir}" "${newdir}"
+}
+
+profile_configure_system_native()
+{
+	local root="${1}"
+	local arch="${2}"
+	local plat="${3}"
+
+	"prof_${profile}_configure_system_native" "${root}" "${arch}" "${plat}"
+}
+
+profile_configure_system_foreign()
+{
+	local root="${1}"
+	local arch="${2}"
+	local plat="${3}"
+
+	"prof_${profile}_configure_system_foreign" "${root}" "${arch}" "${plat}"
+}
diff --git a/src/profile/local.mk b/src/profile/local.mk
new file mode 100644
index 0000000..c303390
--- /dev/null
+++ b/src/profile/local.mk
@@ -0,0 +1,2 @@
+prokit_SOURCES += \
+	src/profile/proteanos.sh
diff --git a/src/profile/proteanos.sh b/src/profile/proteanos.sh
new file mode 100644
index 0000000..0e146ee
--- /dev/null
+++ b/src/profile/proteanos.sh
@@ -0,0 +1,258 @@
+# ProteanOS architecture detection and feeds lists.
+#
+# Copyright (C) 2013, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+prof_proteanos_fstab_linux="\
+proc   /proc    proc   defaults
+sys    /sys     sysfs  defaults
+/dev   /dev     none   bind
+devpts /dev/pts devpts noexec,nosuid,gid=5,mode=0620
+"
+prof_proteanos_install_service=\
+'#!/bin/sh /etc/rc.common
+
+start()
+{
+	log "Configuring packages"
+	printf "disabled\n" >/etc/rc.policy
+	opkg install $(opkg list-installed | cut -d " " -f 1)
+	printf "enabled\n" >/etc/rc.policy
+	rm "${SCRIPT}"
+}
+'
+
+prof_proteanos_normalize_suite()
+{
+	local suite="${1}"
+
+	case "${suite}" in
+		*/*) printf '%s\n' "${suite}";;
+		*)   printf 'dev/%s\n' "${suite}";;
+	esac
+
+	return 0
+}
+
+prof_proteanos_detect_arch()
+{
+	local uname_m=
+	local uname_s=
+	local arch=
+
+	uname_m="$( (uname -m) 2>/dev/null)" || uname_m='unknown'
+	uname_s="$( (uname -s) 2>/dev/null)" || uname_s='unknown'
+
+	case "${uname_m}:${uname_s}" in
+		'x86_64:Linux')
+			arch='amd64-linux-glibc'
+			;;
+		'i686:Linux')
+			arch='i686-linux-glibc'
+			;;
+		*)
+			arch=''
+	esac
+
+	printf '%s\n' "${arch}"
+}
+
+prof_proteanos_default_plat()
+{
+	printf 'dev\n'
+}
+
+prof_proteanos_select_mirror()
+{
+	local mirrors=
+	local mirrors_count=
+	local mirror_num=
+
+	mirrors="$(wget -q -O - \
+		'http://files.proteanos.com/pub/proteanos-mirrors-http')"
+	mirrors_count=$(printf '%s\n' "${mirrors}" | wc -l)
+	rand
+	mirror_num=$(($rand_x % $mirrors_count + 1))
+
+	printf '%s\n' "${mirrors}" | sed -n "${mirror_num}p"
+}
+
+prof_proteanos_validate_archplat()
+{
+	local mirror="${1}"
+	local arch="${2}"
+	local plat="${3}"
+	local suite="${4}"
+
+	while read -r archplat; do
+		case "${archplat}" in
+			"${arch}/${plat}")
+				return 0
+				;;
+		esac
+	done <<-EOF
+		$(wget -q -O - "${mirror}/feeds/${suite}/Manifest" | sed \
+			's|/[^/]*$||; /^all\//d; /\/all$/d;')
+		EOF
+
+	return 1
+}
+
+prof_proteanos_feeds()
+{
+	local mirror="${1}"
+	local arch="${2}"
+	local plat="${3}"
+	local suite="${4}"
+	local a=
+	local p=
+	local s=
+	
+	for a in "${arch}" 'all'; do
+		for p in "${plat}" 'all'; do
+			for s in 'base'; do
+				printf 'src/gz proteanos_%s_%s_%s_%s_%s ' \
+					"${suite%/*}" "${suite#*/}" \
+					"${a}" "${p}" "${s}"
+				printf '%s/feeds/%s/%s/%s/%s/Packages.gz\n' \
+					"${mirror}" "${suite}" \
+					"${a}" "${p}" "${s}"
+			done
+		done
+	done
+
+	for s in 'base'; do
+		printf 'src/gz proteanos_%s_%s_%s_%s_%s ' \
+			"${suite%/*}" "${suite#*/}" \
+			'src' 'all' "${s}"
+		printf '%s/feeds/%s/%s/%s/%s/Packages.gz\n' \
+			"${mirror}" "${suite}" \
+			'src' 'all' "${s}"
+	done
+}
+
+prof_proteanos_dep_fields()
+{
+	printf 'Depends Pre-Depends'
+}
+
+prof_proteanos_include_pkg()
+{
+	local name="${1}"
+	local value="${2}"
+
+	if [ "x${name}" = 'xessential' ]; then
+		if [ "x${value}" = 'xyes' ]; then
+			return 0
+		fi
+	fi
+
+	return 1
+}
+
+prof_proteanos_get_fstab()
+{
+	local arch="${1}"
+	local plat="${2}"
+
+	case "${arch}" in
+		*-linux-*)
+			printf '%s\n' "${prof_proteanos_fstab_linux}"
+			;;
+	esac
+}
+
+prof_proteanos_file_systems_mounted()
+{
+	local root="${1}"
+	local arch="${2}"
+	local plat="${3}"
+
+	[ -e "${root}/dev/null" ]
+}
+
+prof_proteanos_bind_mount()
+{
+	local arch="${1}"
+	local plat="${2}"
+	local olddir="${3}"
+	local newdir="${4}"
+
+	case "${arch}" in
+		*-linux-*)
+			mount -o bind "${olddir}" "${newdir}"
+			;;
+	esac
+}
+
+prof_proteanos_bind_umount()
+{
+	local arch="${1}"
+	local plat="${2}"
+	local olddir="${3}"
+	local newdir="${4}"
+
+	case "${arch}" in
+		*-linux-*)
+			umount "${newdir}"
+			;;
+	esac
+}
+
+prof_proteanos_configure_system_native()
+{
+	local root="${1}"
+	local arch="${2}"
+	local plat="${3}"
+
+	printf 'disabled\n' >"${root}/etc/rc.policy"
+	opkg_install_all "${root}"
+	if [ "x${plat}" = 'xdev' ]; then
+		[ -r /etc/resolv.conf ] && cp /etc/resolv.conf "${root}/etc"
+		[ -r /etc/hostname ] && cp /etc/hostname "${root}/etc"
+	else
+		printf 'enabled\n' >"${root}/etc/rc.policy"
+		printf 'proteanos\n' >"${root}/etc/hostname"
+	fi
+	[ -e "${root}/etc/passwd" ] || printf \
+		'root::0:0:root:/root:/bin/sh\n' >"${root}/etc/passwd"
+	[ -e "${root}/etc/group" ] || printf \
+		'root:x:0:\n' >"${root}/etc/group"
+}
+
+prof_proteanos_configure_system_foreign()
+{
+	local root="${1}"
+	local arch="${2}"
+	local plat="${3}"
+
+	printf '%s' "${prof_proteanos_install_service}" \
+		>"${root}/etc/rc.d/S10install"
+	chmod 0755 "${root}/etc/rc.d/S10install"
+	printf 'proteanos\n' >"${root}/etc/hostname"
+	[ -e "${root}/etc/passwd" ] || printf \
+		'root::0:0:root:/root:/bin/sh\n' >"${root}/etc/passwd"
+	[ -e "${root}/etc/group" ] || printf \
+		'root:x:0:\n' >"${root}/etc/group"
+}
+
+prof_proteanos_register()
+{
+	register_profile 'proteanos'
+}
+__init prof_proteanos_register
diff --git a/src/rand.sh b/src/rand.sh
new file mode 100644
index 0000000..872d3fb
--- /dev/null
+++ b/src/rand.sh
@@ -0,0 +1,42 @@
+# Linear congruential pseudorandom number generator
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+rand_x=1
+
+srand()
+{
+	local x="${1}"
+
+	case "${x}" in
+		*[!0-9]*)
+			warn "$(get_msg 'rand_bad_x')"
+			return 1
+			;;
+	esac
+
+	rand_x=${x}
+}
+
+rand()
+{
+	# Increment, multiplier, and modulus values are those used in glibc.
+	rand_x=$((1103515245 * $rand_x + 12345))
+	rand_x=$(($rand_x % 4294967296))
+}
diff --git a/src/session.sh b/src/session.sh
new file mode 100644
index 0000000..6453fae
--- /dev/null
+++ b/src/session.sh
@@ -0,0 +1,210 @@
+# Functions for managing prokit sessions
+#
+# Copyright (C) 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+session_id=
+session_root=
+session_arch=
+session_plat=
+session_mountdir=
+session_atexit=
+session_sigs=
+
+session_begin()
+{
+	local root="${1}"
+	local mountdir="${2}"
+	local atexit="${3}"
+	local installing="${4}"
+
+	rand
+	session_id=${rand_x}
+	session_root="${root}"
+	session_arch="$(cat "${root}/etc/proteanos_arch")"
+	session_plat="$(cat "${root}/etc/proteanos_plat")"
+	session_mountdir="${mountdir}"
+	session_atexit="${atexit}"
+
+	[ -d "${session_root}/prokit" ] || mkdir "${session_root}/prokit"
+	if [ -f "${session_root}/prokit/installing" ] && ! ${installing}; then
+		error 2 "$(get_msg 'install_running')"
+	fi
+
+	session_set_sigs
+
+	if ! mutex_timedlock "${session_root}/prokit/sessions.lock" 5; then
+		error 2 "$(get_msg 'cant_lock_sessions')"
+	fi
+
+	# Check for a sessions pool.
+	if [ -d "${session_root}/prokit/sessions" ]; then
+		if ! profile_file_systems_mounted "${session_root}" \
+				"${session_arch}" "${session_plat}"; then
+			# If a sessions pool exists but the file systems aren't
+			# mounted, clean up the old sessions and mount the file
+			# systems.
+			rmdir "${session_root}/prokit/sessions/"*
+			session_mount
+		fi
+	else
+		# If the sessions pool doesn't exist, create it and mount the
+		# file systems.
+		mkdir "${session_root}/prokit/sessions"
+		session_mount
+	fi
+
+	# Register the session.
+	mkdir "${session_root}/prokit/sessions/${session_id}"
+	mkdir "${session_root}/prokit/sessions/${session_id}/wd"
+	profile_bind_mount "${session_arch}" "${session_plat}" \
+		"${session_mountdir}" \
+		"${session_root}/prokit/sessions/${session_id}/wd"
+
+	mutex_unlock "${session_root}/prokit/sessions.lock"
+}
+
+session_end()
+{
+	trap : ${session_sigs}
+
+	${session_atexit}
+
+	# Unregister the session.
+	profile_bind_umount "${session_arch}" "${session_plat}" \
+		"${session_mountdir}" \
+		"${session_root}/prokit/sessions/${session_id}/wd"
+	rmdir "${session_root}/prokit/sessions/${session_id}/wd"
+	rmdir "${session_root}/prokit/sessions/${session_id}"
+
+	if ! mutex_is_unlockable "${session_root}/prokit/sessions.lock"; then
+		if ! mutex_timedlock "${session_root}/prokit/sessions.lock" 5
+		then
+			error 2 "$(get_msg 'cant_lock_sessions')"
+		fi
+	fi
+
+	# Clear the sessions pool.  If there are no more sessions, unmount the
+	# file systems.
+	if rmdir "${session_root}/prokit/sessions" 2>/dev/null; then
+		session_umount
+	fi
+
+	mutex_unlock "${session_root}/prokit/sessions.lock"
+	
+	trap - ${session_sigs}
+}
+
+session_id()
+{
+	printf '%d\n' ${session_id}
+	return 0
+}
+
+session_dir()
+{
+	printf '/prokit/sessions/%d\n' ${session_id}
+	return 0
+}
+
+session_exec()
+{
+	local args=
+	local session_dir=
+
+	args=''
+	for arg in "${@}"; do
+		arg="'$(printf '%s\n' "${arg}" | sed "s/'/'\\\\''/g")'"
+		args="${args} ${arg}"
+	done
+	session_dir="/prokit/sessions/${session_id}/wd"
+	chroot "${session_root}" /bin/sh -c "cd ${session_dir}; ${args}"
+}
+
+session_mount()
+{
+	local fs=
+	local dir=
+	local fstype=
+	local options=
+
+	while read fs dir fstype options; do
+		[ "x${dir}" = 'x' ] && continue
+		mount -t "${fstype}" -o "${options}" "${fs}" \
+			"${session_root}/${dir}"
+	done <<-EOF
+		$(profile_get_fstab "${session_arch}" "${session_plat}")
+		EOF
+}
+
+session_umount()
+{
+	local fs=
+	local dir=
+	local fstype=
+	local options=
+
+	while read fs dir fstype options; do
+		[ "x${dir}" = 'x' ] && continue
+		# umount sometimes complains that the /dev file system is busy.
+		# Here's a kludge to try to handle that.  We better make sure
+		# bind mounts get unmounted; otherwise, `rm -Rf ${root}` can be
+		# painful.
+		while ! umount "${session_root}/${dir}"; do
+			sleep 1
+		done
+	done <<-EOF
+		$(profile_get_fstab "${session_arch}" "${session_plat}" | \
+			sed -n '1!G;h;$p')
+		EOF
+}
+
+session_set_sigs()
+{
+	local i=
+	local sig=
+
+	# We need the signal *number* in the signal handler.  The only portable
+	# and easy way to get the number of a named signal is to search for it
+	# as in the following loop hack.
+	i=0
+	session_sigs=''
+	while [ ${i} -lt 127 ]; do
+		i=$(($i + 1))
+		sig="$(kill -l ${i} 2>/dev/null)" || continue
+		case "${sig}" in
+			'HUP' | 'INT' | 'QUIT' | 'ABRT' | 'ALRM' | 'TERM')
+				session_sigs="${session_sigs} ${i}"
+				trap "session_handle_sig ${i}" ${i}
+				;;
+		esac
+	done
+}
+
+session_handle_sig()
+{
+	local sig="${1}"
+
+	session_end
+
+	if [ "x${exit_status:+set}" = 'xset' ]; then
+		exit ${exit_status}
+	else
+		exit $((128 + $sig))
+	fi
+}
diff --git a/src/substvars.sh b/src/substvars.sh
new file mode 100644
index 0000000..c2bc3f8
--- /dev/null
+++ b/src/substvars.sh
@@ -0,0 +1,103 @@
+# Functions for setting and substituting variables
+#
+# Copyright (C) 2012, 2014  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+substvars_max_depth=50
+
+set_substvar()
+{
+	local name="${1}"
+	local value="${2}"
+
+	# Convert variable name to lower case and validate.
+	name="$(printf '%s\n' "${name}" | tr 'A-Z-' 'a-z_')"
+	case "${name:- }" in
+		*[!a-z0-9_]*)
+			warn "$(get_msg 'substvar_invalid')" "${name}"
+			return 1
+			;;
+	esac
+
+	# Trim leading and trailing newline characters from value.
+	value="$(printf '%s\n' "${value}" | sed -n '
+		H;            # Store each input line in the hold space.
+		${            # At the last line of input:
+		  g;          # Restore the hold space into the pattern space.
+		  s/^[\n]*//; # Remove leading newline characters.
+		  s/[\n]*$//; # Remove trailing newline characters.
+		  p;          # Print the results.
+		};
+		')"
+
+	# Escape single quotes in value.
+	value="$(printf '%s\n' "${value}" | sed "s/'/'\\\\''/g")"
+
+	eval "substvar_${name}='${value}'"
+
+	return 0
+}
+
+substvars()
+{
+	local string="${1}"
+	local depth=
+	local lhs=
+	local name=
+	local rhs=
+	local old_rhs=
+	local value=
+
+	# Logic inspired by that of dpkg's Dpkg::Substvars::substvars()
+	# subroutine.
+
+	depth=0
+
+	while :; do
+		lhs="${string%%\$\{*}"
+		if [ ${#lhs} -eq ${#string} ]; then
+			# No "${" was found.
+			break
+		fi
+		string="${string#*\$\{}"
+		name="${string%%\}*}"
+		rhs="${string#*\}}"
+
+		if [ ${#rhs} -lt ${#old_rhs} ]; then
+			# Reset the nesting counter if we've advanced the right
+			# side of the matched space.
+			depth=0
+		fi
+		if [ ${depth} -ge ${substvars_max_depth} ]; then
+			# Warn of possible recursion.
+			warn "$(get_msg 'substvar_deep_nesting')"
+			return 1
+		fi
+		old_rhs="${rhs}"
+
+		# Perform the substitution.
+		name="$(printf '%s\n' "${name}" | tr 'A-Z-' 'a-z_')"
+		value="$(eval "printf '%s\n' \"\${substvar_${name}}\"")"
+		string="${lhs}${value}${rhs}"
+		depth=$(($depth + 1))
+	done
+
+	printf '%s\n' "${string}"
+
+	return 0
+}
diff --git a/src/vardata.sh b/src/vardata.sh
new file mode 100644
index 0000000..0c68d67
--- /dev/null
+++ b/src/vardata.sh
@@ -0,0 +1,52 @@
+# Functions for getting variable/runtime data
+#
+# Copyright (C) 2015  Patrick "P. J." McDermott
+#
+# This file is part of the ProteanOS Development Kit.
+#
+# The ProteanOS Development Kit is free software: you can redistribute
+# it and/or modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# The ProteanOS Development Kit is distributed in the hope that it
+# will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the ProteanOS Development Kit.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+VARDATA_DIRS='mount'
+
+vardatadir=
+
+init_vardata()
+{
+	local dir=
+
+	if ${in_place}; then
+		vardatadir="${builddir}/var"
+		for dir in ${VARDATA_DIRS}; do
+			mkdir -p "${vardatadir}/${dir}"
+		done
+	else
+		vardatadir="${PKGLOCALSTATEDIR}"
+	fi
+
+	return 0
+}
+
+get_vardata_dir()
+{
+	local dir="${1}"
+
+	case " ${VARDATA_DIRS} " in
+		*" ${dir} "*)
+			printf '%s/%s' "${vardatadir}" "${dir}"
+			;;
+	esac
+
+	return 0
+}