diff --git a/build_library/toolchain_util.sh b/build_library/toolchain_util.sh
index e841f33057..74f40d7c3e 100644
--- a/build_library/toolchain_util.sh
+++ b/build_library/toolchain_util.sh
@@ -105,6 +105,30 @@ get_board_profile() {
     done
 }
 
+# Usage: get_board_binhost [-t] board [version...]
+# -t: toolchain only, full rebuilds re-using toolchain pkgs
+# If no versions are specified the current and SDK versions are used.
+get_board_binhost() {
+    local toolchain_only=0 board ver
+    if [[ "$1" == "-t" ]]; then
+        toolchain_only=1
+        shift
+    fi
+    board="$1"
+    shift
+
+    if [[ $# -eq 0 ]]; then
+        set -- "${COREOS_VERSION_ID}" "${COREOS_SDK_VERSION}"
+    fi
+
+    for ver in "$@"; do
+        if [[ $toolchain_only -eq 0 ]]; then
+            echo "${COREOS_DOWNLOAD_ROOT}/${board}/${ver}/pkgs/"
+        fi
+        echo "${COREOS_DOWNLOAD_ROOT}/${board}/${ver}/toolchain/"
+    done
+}
+
 # Usage: get_cross_pkgs chost [chost2...]
 get_cross_pkgs() {
     local cross_chost native_pkg
diff --git a/build_packages b/build_packages
index ed9e383a54..0f408aedb8 100755
--- a/build_packages
+++ b/build_packages
@@ -47,6 +47,10 @@ show_help_if_requested "$@"
 # The following options are advanced options, only available to those willing
 # to read the source code. They are not shown in help output, since they are
 # not needed for the typical developer workflow.
+DEFINE_string getbinpkgver "" \
+  "Use binary packages from a specific version."
+DEFINE_boolean toolchainpkgonly $FLAGS_FALSE \
+  "Use binary packages only for the board toolchain."
 DEFINE_string accept_licenses "" \
   "Licenses to append to the accept list."
 DEFINE_boolean fast "${DEFAULT_FAST}" \
@@ -91,7 +95,7 @@ check_gsutil_opts
 CHROMITE_BIN="${GCLIENT_ROOT}/chromite/bin"
 
 # Before we can run any tools, we need to update chroot or setup_board.
-UPDATE_ARGS=()
+UPDATE_ARGS=( --regen_configs )
 if [[ -n ${FLAGS_accept_licenses} ]]; then
   UPDATE_ARGS+=( --accept_licenses "${FLAGS_accept_licenses}" )
 fi
@@ -107,6 +111,14 @@ if [ "${FLAGS_usepkg}" -eq "${FLAGS_TRUE}" ]; then
   else
     UPDATE_ARGS+=( --nogetbinpkg )
   fi
+  if [[ "${FLAGS_toolchainpkgonly}" -eq "${FLAGS_TRUE}" ]]; then
+    UPDATE_ARGS+=( --toolchainpkgonly )
+  else
+    UPDATE_ARGS+=( --notoolchainpkgonly )
+  fi
+  if [[ -n "${FLAGS_getbinpkgver}" ]]; then
+    UPDATE_ARGS+=( --getbinpkgver="${FLAGS_getbinpkgver}" )
+  fi
 else
   UPDATE_ARGS+=( --nousepkg )
 fi
diff --git a/setup_board b/setup_board
index ff278bc58a..dcde4975a3 100755
--- a/setup_board
+++ b/setup_board
@@ -33,6 +33,10 @@ show_help_if_requested "$@"
 # The following options are advanced options, only available to those willing
 # to read the source code. They are not shown in help output, since they are
 # not needed for the typical developer workflow.
+DEFINE_string getbinpkgver "" \
+  "Use binary packages from a specific version."
+DEFINE_boolean toolchainpkgonly $FLAGS_FALSE \
+  "Use binary packages only for the board toolchain."
 DEFINE_string accept_licenses "" \
   "Licenses to append to the accept list."
 DEFINE_boolean fast "${DEFAULT_FAST}" \
@@ -124,6 +128,16 @@ EOF
   sudo_multi "${cmds[@]}"
 }
 
+generate_binhost_list() {
+  local t
+  [[ "${FLAGS_toolchainpkgonly}" -eq "${FLAGS_TRUE}" ]] && t="-t"
+  FLAGS_getbinpkgver="${FLAGS_getbinpkgver/current/${COREOS_VERSION_ID}}"
+  FLAGS_getbinpkgver="${FLAGS_getbinpkgver/latest/${COREOS_VERSION_ID}}"
+  FLAGS_getbinpkgver="${FLAGS_getbinpkgver/sdk/${COREOS_SDK_VERSION}}"
+
+  get_board_binhost $t "${BOARD}" ${FLAGS_getbinpkgver}
+}
+
 # Parse command line flags
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
@@ -180,6 +194,7 @@ BOARD_PROFILE="${BOARD_ETC}/portage/profile"
 BOARD_ARCH=$(get_board_arch "$BOARD")
 BOARD_CHOST=$(get_board_chost ${BOARD})
 PORTAGE_PROFILE=$(get_board_profile "$BOARD")
+BOARD_BINHOST=$(generate_binhost_list)
 
 if [ -d "${BOARD_ROOT}" ]; then
   if [[ ${FLAGS_force} -eq ${FLAGS_TRUE} ]]; then
@@ -237,6 +252,7 @@ ROOT="${BOARD_ROOT}/"
 MAKEOPTS="--jobs=${NUM_JOBS} --load-average=${NUM_JOBS}"
 PKG_CONFIG="pkg-config-${BOARD_VARIANT}"
 BOARD_USE="${BOARD_VARIANT}"
+PORTAGE_BINHOST="${BOARD_BINHOST}"
 ${ACCEPT_LICENSE}
 EOF