Update debian/control suggests to support building arm on amd64 and add contrib script to install deps

Author: JedMeister

contrib/install-arm-on-amd-deps

@@ -0,0 +1,56 @@
+#!/bin/bash -eu
+
+QUIET=
+pkgs=(binfmt-support qemu-system-arm qemu-user-static)
+bins=(/usr/sbin/update-binfmts /usr/bin/qemu-system-arm /usr/bin/qemu-arm-static)
+pkgs_to_install=()
+
+usage() {
+    cat <<EOF
+$(basename "$0") [-h|--help] [-q|--quiet]
+
+Checks packages required to build arm64 on amd64 are installed
+and if not, installs them.
+
+args::
+
+    -h|--help   show this help and exit
+    -q|--quiet  no output
+EOF
+}
+
+while [[ $# -ne 0 ]]; do
+    case $1 in
+        -h|--help)
+            usage;;
+        -q|--quiet)
+            QUIET=y;;
+        *)
+            echo "Unknown option: $1" >&2
+            exit 1;;
+    esac
+    shift
+done
+
+install_pkgs() {
+    COM1=$(apt-get update 2>&1)
+    COM2=$(apt-get install -y "$@" 2>&1) 
+    if [[ -z "$QUIET" ]]; then
+        $COM1 >/dev/null
+        $COM2 >/dev/null
+    else
+        $COM1
+        $COM2
+    fi
+}
+
+for i in "${!pkgs[@]}"; do
+    if ! which "${bins[$i]}"; then
+        pkgs_to_install+=("${pkgs[$i]}")
+    fi
+done
+# shellcheck disable=SC2128
+# even if there are no elements in a array; ${foo[@]} still isn't "empty"
+if [[ -n "$pkgs_to_install" ]]; then
+    install "$pkgs_to_install"
+fi

debian/control

@@ -25,4 +25,7 @@ Recommends:
 Suggests:
  dd,
  wodim,
+ binfmt-support,
+ qemu-system-arm,
+ qemu-user-static
 Description: TurnKey GNU/Linux product fabrication framework

debian/install

@@ -1 +1,2 @@
 share/*     usr/share/fab
+contrib/install-arm-on-amd-deps   usr/bin