diff --git a/bbb-convert-stage-2.sh b/bbb-convert-stage-2.sh
index c2be2b9..c2106b2 100755
--- a/bbb-convert-stage-2.sh
+++ b/bbb-convert-stage-2.sh
@@ -4,15 +4,12 @@ sdimg_boot_dir=$1
 embedded_rootfs_dir=$2
 uboot_backup_dir=${embedded_rootfs_dir}/opt/backup/uboot
 
-echo $sdimg_boot_dir
-echo $embedded_rootfs_dir
-
 [ ! -d "${sdimg_boot_dir}" ] && \
-    { echo "Error: boot location not mounted."; exit 1; }
+    { log "Error: boot location not mounted."; exit 1; }
 [ ! -d "${embedded_rootfs_dir}" ] && \
-    { echo "Error: embedded content not mounted."; exit 1; }
+    { log "Error: embedded content not mounted."; exit 1; }
 [[ ! -f $uboot_backup_dir/MLO || ! -f $uboot_backup_dir/u-boot.img ]] && \
-    { echo "Error: cannot find U-Boot related files."; exit 1; }
+    { log "Error: cannot find U-Boot related files."; exit 1; }
 
 set_uenv() {
   cat <<- 'EOF' | sudo tee --append $sdimg_boot_dir/uEnv.txt 2>&1 >/dev/null
@@ -45,6 +42,6 @@ sudo cp ${uboot_backup_dir}/u-boot.img ${sdimg_boot_dir}
 # Create U-Boot purposed uEnv.txt file.
 set_uenv
 
-echo -e "\nStage done."
+log "\tDone."
 
 exit 0
diff --git a/bbb-convert-stage-3.sh b/bbb-convert-stage-3.sh
index dda63ae..20ae0a2 100755
--- a/bbb-convert-stage-3.sh
+++ b/bbb-convert-stage-3.sh
@@ -4,9 +4,9 @@ sdimg_primary_dir=$1
 embedded_rootfs_dir=$2
 
 [ ! -d "${sdimg_primary_dir}" ] &&  \
-    { echo "Error: rootfs location not mounted."; exit 1; }
+    { log "Error: rootfs location not mounted."; exit 1; }
 [ ! -d "${embedded_rootfs_dir}" ] && \
-    { echo "Error: embedded content not mounted."; exit 1; }
+    { log "Error: embedded content not mounted."; exit 1; }
 
 # Copy rootfs partition.
 sudo cp -ar ${embedded_rootfs_dir}/* ${sdimg_primary_dir}
@@ -15,6 +15,6 @@ sudo cp -ar ${embedded_rootfs_dir}/* ${sdimg_primary_dir}
 sudo install -d -m 755 ${sdimg_primary_dir}/boot/efi
 sudo install -d -m 755 ${sdimg_primary_dir}/data
 
-echo -e "\nStage done."
+log "\tDone."
 
 exit 0
diff --git a/bbb-convert-stage-5.sh b/bbb-convert-stage-5.sh
index 310e827..86568c3 100755
--- a/bbb-convert-stage-5.sh
+++ b/bbb-convert-stage-5.sh
@@ -44,6 +44,7 @@ device_type=
 keep=0
 efi_boot=EFI/BOOT
 EFI_STUB_VER="4.12.0"
+build_log=$output_dir/build.log
 
 declare -a mender_disk_mappings
 
@@ -68,13 +69,14 @@ get_kernel_version() {
 #
 #  $1 - linux kernel version
 build_env_lock_boot_files() {
+  log "\tBuilding boot scripts and tools."
   local grubenv_repo_vc_dir=$grubenv_dir/.git
   local grubenv_build_dir=$grubenv_dir/build
 
   mkdir -p $grubenv_dir
 
   if [ ! -d $grubenv_repo_vc_dir ]; then
-    git clone https://github.com/mendersoftware/grub-mender-grubenv.git $grubenv_dir
+    git clone https://github.com/mendersoftware/grub-mender-grubenv.git $grubenv_dir >> "$build_log" 2>&1
   fi
   cd $grubenv_dir
 
@@ -90,8 +92,8 @@ build_env_lock_boot_files() {
   sed -i '/^kernel_imagetype/s/=.*$/='${kernel_imagetype}'/' mender_grubenv_defines
   sed -i '/^kernel_devicetree/s/=.*$/='${kernel_devicetree//\//\\/}'/' mender_grubenv_defines
 
-  make --quiet
-  make --quiet DESTDIR=$grubenv_build_dir install
+  make --quiet >> "$build_log" 2>&1
+  make --quiet DESTDIR=$grubenv_build_dir install >> "$build_log" 2>&1
   cd $output_dir
 }
 
@@ -99,6 +101,8 @@ build_env_lock_boot_files() {
 #
 #  $1 - linux kernel version
 build_grub_efi() {
+  log "\tBuilding GRUB efi file."
+
   local grub_build_dir=$grub_dir/build
   local grub_arm_dir=$grub_build_dir/arm
   local host=$(uname -m)
@@ -109,16 +113,16 @@ build_grub_efi() {
 
   # Build grub modules for arm platform and executables for the host.
   if [ ! -d $grub_repo_vc_dir ]; then
-    git clone git://git.savannah.gnu.org/grub.git $grub_dir
+    git clone git://git.savannah.gnu.org/grub.git $grub_dir >> "$build_log" 2>&1
   fi
 
   cd $grub_dir
-  make --quiet distclean
+  make --quiet distclean >> "$build_log" 2>&1
 
   if [ $(version $version) -lt $(version $EFI_STUB_VER) ]; then
     # To avoid error message: "plain image kernel not supported - rebuild
     # with CONFIG_(U)EFI_STUB enabled" - use a specific commit.
-    git checkout 9b37229f0
+    git checkout 9b37229f0 >> "$build_log" 2>&1
   fi
 
   mkdir -p $grub_arm_dir
@@ -127,27 +131,27 @@ build_grub_efi() {
   local cores=$(nproc)
 
   # First build host tools.
-  ./autogen.sh > /dev/null
-  ./configure --quiet CC=gcc --target=${host} --with-platform=efi --prefix=$grub_host_dir
-  make --quiet -j$cores
-  make --quiet install
+  ./autogen.sh >> "$build_log" 2>&1
+  ./configure --quiet CC=gcc --target=${host} --with-platform=efi --prefix=$grub_host_dir >> "$build_log" 2>&1
+  make --quiet -j$cores >> "$build_log" 2>&1
+  make --quiet install >> "$build_log" 2>&1
 
   # Clean workspace.
-  make --quiet clean
-  make --quiet distclean
+  make --quiet clean >> "$build_log" 2>&1
+  make --quiet distclean >> "$build_log" 2>&1
 
    # Now build ARM modules.
   ./configure --quiet  --host=$bootloader_toolchain --with-platform=efi \
       --prefix=$grub_arm_dir CFLAGS="-Os -march=armv7-a" \
-      CCASFLAGS="-march=armv7-a" --disable-werror
-  make --quiet -j$cores
-  make --quiet install
+      CCASFLAGS="-march=armv7-a" --disable-werror >> "$build_log" 2>&1
+  make --quiet -j$cores >> "$build_log" 2>&1
+  make --quiet install >> "$build_log" 2>&1
 
   # Build GRUB EFI image.
   ${grub_host_dir}/bin/grub-mkimage  -v -p /$efi_boot -o grub.efi --format=arm-efi \
       -d $grub_arm_dir/lib/grub/arm-efi/  boot linux ext2 fat serial part_msdos \
       part_gpt  normal efi_gop iso9660 configfile search loadenv test cat echo \
-      gcry_sha256 halt hashsum loadenv reboot &> /dev/null
+      gcry_sha256 halt hashsum loadenv reboot >> "$build_log" 2>&1
 
   rc=$?
 
@@ -179,7 +183,7 @@ set_uenv() {
 #  $1 - boot partition mountpoint
 #  $2 - primary partition mountpoint
 install_files() {
-  echo "Installing GRUB files..."
+  log "\tInstalling GRUB files."
   local boot_dir=$1
   local rootfs_dir=$2
 
@@ -194,7 +198,7 @@ install_files() {
   # Make sure env, lock, lock.sha256sum files exists in working directory.
   [[ ! -d $grubenv_efi_boot_dir/mender_grubenv1 || \
      ! -d $grubenv_efi_boot_dir/mender_grubenv2 ]] && \
-      { echo "Error: cannot find mender grub related files."; return 1; }
+      { log "Error: cannot find mender grub related files."; return 1; }
 
   sudo install -d -m 755 $efi_boot_dir
 
@@ -215,30 +219,28 @@ install_files() {
 }
 
 do_install_bootloader() {
-  echo "Setting bootloader..."
-
   if [ -z "${mender_disk_image}" ]; then
-    echo "Mender raw disk image not set. Aborting."
+    log "Mender raw disk image not set. Aborting."
     exit 1
   fi
 
   if [ -z "${bootloader_toolchain}" ]; then
-    echo "ARM GCC toolchain not set. Aborting."
+    log "ARM GCC toolchain not set. Aborting."
     exit 1
   fi
 
   if [ -z "${device_type}" ]; then
-    echo "Target device type name not set. Aborting."
+    log "Target device type name not set. Aborting."
     exit 1
   fi
 
-  if [[ $(which ${bootloader_toolchain}-gcc) = 1 ]]; then
-    echo "Error: ARM GCC not found in PATH. Aborting."
+  if ! [ -x "$(command -v ${bootloader_toolchain}-gcc)" ]; then
+    log "Error: ARM GCC not found in PATH. Aborting."
     exit 1
   fi
 
   [ ! -f $mender_disk_image ] && \
-      { echo "$mender_disk_image - file not found. Aborting."; exit 1; }
+      { log "$mender_disk_image - file not found. Aborting."; exit 1; }
 
   # Map & mount Mender compliant image.
   create_device_maps $mender_disk_image mender_disk_mappings
@@ -257,15 +259,15 @@ do_install_bootloader() {
   sudo mount ${map_primary} ${path_primary}
 
   get_kernel_version ${path_primary} kernel_version
-  echo -e "\nKernel version: $kernel_version"
+  log "\tFound kernel version: $kernel_version"
 
   build_env_lock_boot_files $kernel_version
 
   build_grub_efi $kernel_version
   rc=$?
 
-  [[ $rc -ne 0 ]] && { echo "Error: grub.efi building failure. Aborting."; } \
-                  || { echo "Successful grub.efi building."; \
+  [[ $rc -ne 0 ]] && { log "\tBuilding grub.efi failed. Aborting."; } \
+                  || { log "\tBuilding grub.efi succeeded."; \
                        install_files ${path_boot} ${path_primary}; }
 
   # Back to working directory.
@@ -276,8 +278,7 @@ do_install_bootloader() {
   rm -rf $output_dir/sdimg
 
   [[ $keep -eq 0 ]] && { rm -rf $grubenv_dir $grub_dir; }
-  [[ $rc -ne 0 ]] && { echo -e "\nStage failure."; exit 1; } \
-                  || { echo -e "\nStage done."; }
+  [[ $rc -ne 0 ]] && { exit 1; } || { log "\tDone."; }
 }
 
 PARAMS=""
@@ -309,7 +310,7 @@ while (( "$#" )); do
       break
       ;;
     -*)
-      echo "Error: unsupported option $1" >&2
+      log "Error: unsupported option $1"
       exit 1
       ;;
     *)
diff --git a/convert-stage-4.sh b/convert-stage-4.sh
index 1a8de07..6706200 100755
--- a/convert-stage-4.sh
+++ b/convert-stage-4.sh
@@ -121,7 +121,7 @@ get_mender_files_from_upstream() {
 
   mkdir -p $mender_dir
 
-  echo -e "Downloading inventory & identity scripts..."
+  log "\tDownloading inventory & identity scripts."
 
   wget -nc -q -O $mender_dir/mender-device-identity \
     $mender_client_repo/$mender_client_revision/support/mender-device-identity
@@ -152,6 +152,8 @@ install_files() {
   dataconfdir="mender"
   databootdir="u-boot"
 
+  log "\tInstalling files."
+
   # Prepare 'data' partition
   sudo install -d -m 755 ${data_dir}/${dataconfdir}
   sudo install -d -m 755 ${data_dir}/${databootdir}
@@ -163,18 +165,18 @@ install_files() {
 
   # Prepare 'primary' partition
   [ ! -d "$primary_dir/data" ] && \
-      { echo "'data' mountpoint missing. Adding"; \
+      { log "\t'data' mountpoint missing. Adding"; \
         sudo install -d -m 755 ${primary_dir}/data; }
 
   case "$device_type" in
     "beaglebone")
       [ ! -d "$primary_dir/boot/efi" ] && \
-          { echo "'/boot/efi' mountpoint missing. Adding"; \
+          { log "\t'/boot/efi' mountpoint missing. Adding"; \
             sudo install -d -m 755 ${primary_dir}/boot/efi; }
       ;;
     "raspberrypi3")
       [ ! -d "$primary_dir/uboot" ] && \
-          { echo "'/boot/efi' mountpoint missing. Adding"; \
+          { log "\t'/boot/efi' mountpoint missing. Adding"; \
             sudo install -d -m 755 ${primary_dir}/uboot; }
       ;;
   esac
@@ -184,7 +186,7 @@ install_files() {
   sudo install -d ${primary_dir}/${sysconfdir}
   sudo install -d ${primary_dir}/${sysconfdir}/scripts
 
-  sudo ln -s /data/${dataconfdir} ${primary_dir}/${localstatedir}
+  sudo ln -sf /data/${dataconfdir} ${primary_dir}/${localstatedir}
 
   sudo install -m 0755 ${mender_client} ${primary_dir}/${bindir}/mender
 
@@ -197,7 +199,7 @@ install_files() {
   sudo install -m 0644 ${mender_dir}/mender.service ${primary_dir}/${systemd_unitdir}
 
   # Enable menderd service starting on boot.
-  sudo ln -s /lib/systemd/system/mender.service \
+  sudo ln -sf /lib/systemd/system/mender.service \
       ${primary_dir}/etc/systemd/system/multi-user.target.wants/mender.service
 
   sudo install -m 0644 ${mender_dir}/mender.conf ${primary_dir}/${sysconfdir}
@@ -209,7 +211,7 @@ install_files() {
   sudo install -m 0644 ${mender_dir}/version ${primary_dir}/${sysconfdir}/scripts
 
   if [ -n "${demo_host_ip}" ]; then
-    echo "$demo_host_ip docker.mender.io s3.docker.mender.io" | sudo tee -a $primary_dir/etc/hosts
+    sudo sh -c -e "echo '$demo_host_ip docker.mender.io s3.docker.mender.io' >> $primary_dir/etc/hosts";
   fi
 
   if [ -n "${server_cert}" ]; then
@@ -219,33 +221,33 @@ install_files() {
 
 do_install_mender() {
   if [ -z "${mender_disk_image}" ]; then
-    echo "Mender raw disk image not set. Aborting."
+    log "Mender raw disk image not set. Aborting."
     show_help
   fi
 
   if [ -z "${mender_client}" ]; then
-    echo "Mender client binary not set. Aborting."
+    log "Mender client binary not set. Aborting."
     show_help
   fi
 
   if [ -z "${device_type}" ]; then
-    echo "Target device type name not set. Aborting."
+    log "Target device type name not set. Aborting."
     show_help
   fi
 
   if [ -z "${artifact_name}" ]; then
-    echo "Artifact info not set. Aborting."
+    log "Artifact info not set. Aborting."
     show_help
   fi
 
   if [ -z "${server_url}" ] && [ -z "${demo_host_ip}" ] && \
      [ -z "${tenant_token}" ]; then
-    echo "No server type specified. Aborting."
+    log "No server type specified. Aborting."
     show_help
   fi
 
   if [ -n "${server_url}" ] && [ -n "${demo_host_ip}" ]; then
-    echo "Incompatible server type choice. Aborting."
+    log "Incompatible server type choice. Aborting."
     show_help
   fi
 
@@ -260,7 +262,7 @@ do_install_mender() {
   fi
 
   [ ! -f $mender_disk_image ] && \
-      { echo "$mender_disk_image - file not found. Aborting."; exit 1; }
+      { log "$mender_disk_image - file not found. Aborting."; exit 1; }
 
   # Mount rootfs partition A.
   create_device_maps $mender_disk_image mender_disk_mappings
@@ -295,6 +297,8 @@ do_install_mender() {
   detach_device_maps ${mender_disk_mappings[@]}
   rm -rf $output_dir/sdimg
   [[ $keep -eq 0 ]] && { rm -rf $mender_dir; }
+
+  log "\tDone."
 }
 
 PARAMS=""
@@ -345,7 +349,7 @@ while (( "$#" )); do
       break
       ;;
     -*)
-      echo "Error: unsupported option $1" >&2
+      log "Error: unsupported option $1"
       exit 1
       ;;
     *)
diff --git a/mender-convert b/mender-convert
index 7bf1f37..79eaa95 100755
--- a/mender-convert
+++ b/mender-convert
@@ -157,10 +157,10 @@ prootfs_size=
 mender_disk_image=
 raw_disk_image=
 device_type=
-partitions_number=
+mender_disk_counts=
 artifact_name=
 rootfs_partition_id=
-image_type=
+raw_disk_counts=
 mender_client=
 # Mender production certificate.
 server_cert=
@@ -171,6 +171,10 @@ demo_host_ip=
 # Mender hosted token.
 tenant_token=
 
+# Conversion progress.
+declare -i step=1
+declare -i total=
+
 declare -a rootfs_partition_ids=("primary" "secondary")
 declare -a mender_disk_mappings
 declare -a raw_disk_mappings
@@ -178,9 +182,11 @@ declare -a raw_disk_mappings
 declare -a supported_devices=("beaglebone" "raspberrypi3")
 
 do_raw_disk_image_shrink_rootfs() {
+  log "$step/$total Shrinking raw disk image root filesystem..."
+  ((step++))
   if [ -z "${raw_disk_image}" ]; then
-    echo "Raw disk image not set. Aborting."
-    exit 1
+    log "Raw disk image not set. Aborting."
+    return 1
   fi
 
   local count=
@@ -196,7 +202,7 @@ do_raw_disk_image_shrink_rootfs() {
 
   # Find first available loopback device.
   loopdevice=($(losetup -f))
-  [ $? -ne 0 ] && { echo "Error: inaccesible loopback device"; return 1; }
+  [ $? -ne 0 ] && { log "Error: inaccesible loopback device"; return 1; }
 
   # Mount appropriate partition.
   if [[ $count -eq 1 ]]; then
@@ -204,7 +210,7 @@ do_raw_disk_image_shrink_rootfs() {
   elif [[ $count -eq 2 ]]; then
     sudo losetup $loopdevice $raw_disk_image -o $(($rootfsstart * $sector_size))
   else
-    echo "Error: invalid/unsupported embedded raw disk image. Aborting."
+    log "Error: invalid/unsupported embedded raw disk image. Aborting."
     return 1
   fi
 
@@ -214,14 +220,14 @@ do_raw_disk_image_shrink_rootfs() {
   new_size_sectors=$(( $min_size_blocks * $block_size / $sector_size ))
   align_partition_size new_size_sectors $sector_size
 
-  echo -e "Root filesystem size:"
-  echo -e "\nminimal: $(( $min_size_blocks * $block_size ))"
-  echo -e "\naligned: $(( $new_size_sectors * $sector_size ))"
-  echo -e "\nsectors: $new_size_sectors"
+  log "\tRoot filesystem size:\
+       \n\tminimal: $(( $min_size_blocks * $block_size ))  \
+       \n\taligned: $(( $new_size_sectors * $sector_size ))\
+       \n\tsectors: $new_size_sectors"
 
-  sudo e2fsck -y -f $loopdevice
-  sudo resize2fs -p $loopdevice ${new_size_sectors}s
-  sudo e2fsck -y -f $loopdevice
+  sudo e2fsck -y -f $loopdevice >> "$build_log" 2>&1
+  sudo resize2fs -p $loopdevice ${new_size_sectors}s >> "$build_log" 2>&1
+  sudo e2fsck -y -f $loopdevice >> "$build_log" 2>&1
 
   sudo losetup -d $loopdevice
   sudo losetup $loopdevice $raw_disk_image
@@ -229,7 +235,6 @@ do_raw_disk_image_shrink_rootfs() {
   if [[ $count -eq 1 ]]; then
     create_single_disk_partition_table $loopdevice $bootstart $new_size_sectors
   elif [[ $count -eq 2 ]]; then
-    echo
     create_double_disk_partition_table $loopdevice $rootfsstart $new_size_sectors
   fi
 
@@ -237,29 +242,32 @@ do_raw_disk_image_shrink_rootfs() {
   endsector=($(sudo parted $loopdevice -ms unit s print | grep "^$count" | cut -f3 -d: | sed 's/[^0-9]*//g'))
 
   sudo losetup -d $loopdevice
-  echo "Image new endsector: $endsector"
+  log "\tRaw disk image new endsector: $endsector"
   truncate -s $((($endsector+1) * $sector_size)) $raw_disk_image
-  echo "Root filesystem size (sectors): $new_size_sectors"
+  log "\tNew root filesystem size (sectors): $new_size_sectors"
 
   return 0
 }
 
 do_raw_disk_image_create_partitions() {
+  log "$step/$total Repartitioning raw disk image..."
+  ((step++))
+
   if [ -z "$raw_disk_image" ] || [ -z "$device_type" ] || \
      [ -z "$artifact_name" ]; then
     show_help
-    exit 1
+    return 1
   fi
 
   if [[ ! -f ${raw_disk_image} ]]; then
-    echo "Raw disk image not found. Aborting."
-    exit 1
+    log "Raw disk image not found. Aborting."
+    return 1
   fi
 
   local supported=$(echo ${supported_devices[@]} | grep -o $device_type | wc -w)
 
   [[ $supported -eq 0 ]] && \
-      { echo "Error: incorrect device type. Aborting."; return 1; }
+      { log "Error: incorrect device type. Aborting."; return 1; }
 
   mkdir -p $output_dir && cd $output_dir
 
@@ -279,20 +287,22 @@ do_raw_disk_image_create_partitions() {
   fi
 
   analyse_raw_disk_image ${raw_disk_image} pboot_start pboot_size prootfs_size \
-                         sector_size image_type
+                         sector_size raw_disk_counts
 
   [ -z "${prootfs_size}" ] && \
-    { echo "root filesystem size not set. Aborting."; return 1; }
+    { log "root filesystem size not set. Aborting."; return 1; }
+
+  log "\tDetected raw disk image with $raw_disk_counts partition(s)."
 
   local mender_disk_image_size=
   calculate_mender_disk_size $pboot_start $pboot_size  \
                              $prootfs_size $data_part_size_mb  \
                              $sector_size pdata_size mender_disk_image_size
 
-  echo -e "Creating Mender disk image:\
-           \nimage size: ${mender_disk_image_size} bytes\
-           \nroot filesystem size: ${prootfs_size} sectors\
-           \ndata partition size: $pdata_size sectors\n"
+  log "\tCreating Mender disk image:\
+       \n\t\timage size: ${mender_disk_image_size} bytes\
+       \n\t\troot filesystem size: $((${prootfs_size} * $sector_size)) bytes\
+       \n\t\tdata partition size: $(($pdata_size * $sector_size)) bytes"
 
   create_test_config_file $device_type $partition_alignment $vfat_storage_offset \
                           $pboot_size $prootfs_size $pdata_size $mender_disk_image_size \
@@ -301,9 +311,12 @@ do_raw_disk_image_create_partitions() {
   create_mender_disk $mender_disk_image $mender_disk_image_size
   format_mender_disk $mender_disk_image $mender_disk_image_size $pboot_start \
                      $pboot_size $prootfs_size $pdata_size $sector_size
-  verify_mender_disk $mender_disk_image partitions_number
+  verify_mender_disk $mender_disk_image mender_disk_counts
 
   create_device_maps $mender_disk_image mender_disk_mappings
+
+  log "$step/$total Formatting repartitioned raw disk image..."
+  ((step++))
   make_mender_disk_filesystem ${mender_disk_mappings[@]}
 
   case "$device_type" in
@@ -317,7 +330,8 @@ do_raw_disk_image_create_partitions() {
 
   rc=$?
 
-  echo -e "\nCleaning..."
+  log "$step/$total Cleaning intermediate files..."
+  ((step++))
   # Clean and detach.
   detach_device_maps ${mender_disk_mappings[@]}
   detach_device_maps ${raw_disk_mappings[@]}
@@ -325,8 +339,7 @@ do_raw_disk_image_create_partitions() {
   rm -rf $embedded_base_dir
   rm -rf $sdimg_base_dir
 
-  [ $rc -eq 0 ] && { echo -e "\n$mender_disk_image image created."; } \
-                || { echo -e "\n$mender_disk_image image composing failure."; }
+  [ $rc -eq 0 ] || { log "\nRepartitioning of $raw_disk_image image failed."; }
 
   return $rc
 }
@@ -339,49 +352,57 @@ do_make_sdimg_beaglebone() {
   mount_mender_disk ${mender_disk_mappings[@]}
   mount_raw_disk ${raw_disk_mappings[@]}
 
-  echo -e "\nSetting boot partition..."
+  log "$step/$total Setting boot partition..."
+  ((step++))
   stage_2_args="$sdimg_boot_dir $embedded_rootfs_dir"
   ${tool_dir}/bbb-convert-stage-2.sh ${stage_2_args} || ret=$?
-  [[ $ret -ne 0 ]] && { echo "Aborting."; return $ret; }
+  [[ $ret -ne 0 ]] && { log "Aborting."; return $ret; }
 
-  echo -e "\nSetting root filesystem..."
+  log "$step/$total Setting root filesystem partition..."
+  ((step++))
   stage_3_args="$sdimg_primary_dir $embedded_rootfs_dir"
   ${tool_dir}/bbb-convert-stage-3.sh ${stage_3_args} || ret=$?
-  [[ $ret -ne 0 ]] && { echo "Aborting."; return $ret; }
+  [[ $ret -ne 0 ]] && { log "Aborting."; return $ret; }
 
+  log "$step/$total Setting file system table..."
+  ((step++))
   set_fstab $device_type
 
   return $ret
 }
 
 do_make_sdimg_raspberrypi3() {
+  log "$step/$total Setting boot partition..."
+  ((step++))
   image_boot_part=$(fdisk -l ${raw_disk_image} | grep FAT32)
 
   boot_part_start=$(echo ${image_boot_part} | awk '{print $2}')
   boot_part_end=$(echo ${image_boot_part} | awk '{print $3}')
   boot_part_size=$(echo ${image_boot_part} | awk '{print $4}')
 
+  log "\tExtracting boot partition from raw disk image."
   extract_file_from_image ${raw_disk_image} ${boot_part_start} \
                           ${boot_part_size} "boot.vfat"
 
+  stage_2_args="$output_dir ${mender_disk_mappings[0]}"
+  ${tool_dir}/rpi3-convert-stage-2.sh ${stage_2_args} || ret=$?
+  [[ $ret -ne 0 ]] && { return $ret; }
+
+  log "$step/$total Setting root filesystem partition..."
+  ((step++))
   image_rootfs_part=$(fdisk -l ${raw_disk_image} | grep Linux)
 
   rootfs_part_start=$(echo ${image_rootfs_part} | awk '{print $2}')
   rootfs_part_end=$(echo ${image_rootfs_part} | awk '{print $3}')
   rootfs_part_size=$(echo ${image_rootfs_part} | awk '{print $4}')
 
+  log "\tExtracting root filesystem partition from raw disk image."
   extract_file_from_image ${raw_disk_image} ${rootfs_part_start} \
                           ${rootfs_part_size} "rootfs.img"
 
-  echo -e "\nSetting boot partition..."
-  stage_2_args="$output_dir ${mender_disk_mappings[0]}"
-  ${tool_dir}/rpi3-convert-stage-2.sh ${stage_2_args} || ret=$?
-  [[ $ret -ne 0 ]] && { echo "Aborting."; return $ret; }
-
-  echo -e "\nSetting root filesystem..."
   stage_3_args="$output_dir ${mender_disk_mappings[1]}"
   ${tool_dir}/rpi3-convert-stage-3.sh ${stage_3_args} || ret=$?
-  [[ $ret -ne 0 ]] && { echo "Aborting."; return $ret; }
+  [[ $ret -ne 0 ]] && { return $ret; }
 
   mount_mender_disk ${mender_disk_mappings[@]}
 
@@ -389,6 +410,8 @@ do_make_sdimg_raspberrypi3() {
   sudo install -d -m 755 ${sdimg_primary_dir}/uboot
   sudo install -d -m 755 ${sdimg_primary_dir}/data
 
+  log "$step/$total Setting file system table..."
+  ((step++))
   set_fstab $device_type
 
   [[ $keep != "-k" ]] && { rm -f $output_dir/boot.vfat\
@@ -399,17 +422,19 @@ do_make_sdimg_raspberrypi3() {
 }
 
 do_install_mender_to_mender_disk_image() {
-  # Mender executables, service and configuration files installer.
+  log "$step/$total Installing Mender to Mender disk image..."
+  ((step++))
+
   if [ -z "$mender_disk_image" ] || [ -z "$device_type" ] || \
      [ -z "$mender_client" ] || [ -z "$artifact_name" ]; then
     show_help
-    exit 1
+    return 1
   fi
 
   local supported=$(echo ${supported_devices[@]} | grep -o $device_type | wc -w)
 
   [[ $supported -eq 0 ]] && \
-      { echo "Error: incorrect device type. Aborting."; return 1; }
+      { log "Error: incorrect device type. Aborting."; return 1; }
 
   # mender-image-1.5.0
   stage_4_args="-m $mender_disk_image -d $device_type -g ${mender_client} -a ${artifact_name}"
@@ -436,10 +461,8 @@ do_install_mender_to_mender_disk_image() {
 
   eval set -- " ${stage_4_args}"
 
-  export -f create_device_maps
-  export -f detach_device_maps
-
-  ${tool_dir}/convert-stage-4.sh ${stage_4_args}
+  ${tool_dir}/convert-stage-4.sh ${stage_4_args} || ret=$?
+  [[ $ret -ne 0 ]] && { log "\nInstalling Mender to Mender disk image failed."; return $ret; }
 
   # Update test configuration file
   update_test_config_file $device_type artifact-name $artifact_name
@@ -448,24 +471,26 @@ do_install_mender_to_mender_disk_image() {
 }
 
 do_install_bootloader_to_mender_disk_image() {
+  log "$step/$total Installing Bootloader to Mender disk image..."
+  ((step++))
+
   if [ -z "$mender_disk_image" ] || [ -z "$device_type" ] || \
      [ -z "$bootloader_toolchain" ]; then
     show_help
-    exit 1
+    return 1
   fi
 
   local supported=$(echo ${supported_devices[@]} | grep -o $device_type | wc -w)
 
   [[ $supported -eq 0 ]] && \
-      { echo "Error: incorrect device type. Aborting."; return 1; }
+      { log "Error: incorrect device type. Aborting."; return 1; }
 
   case "$device_type" in
     "beaglebone")
       stage_5_args="-m $mender_disk_image -d $device_type -b ${bootloader_toolchain} $keep"
       eval set -- " ${stage_5_args}"
-      export -f create_device_maps
-      export -f detach_device_maps
-      ${tool_dir}/bbb-convert-stage-5.sh ${stage_5_args}
+      ${tool_dir}/bbb-convert-stage-5.sh ${stage_5_args}|| ret=$?
+      [[ $ret -ne 0 ]] && { log "\nInstalling Bootloader failed."; return $ret; }
 
       # Update test configuration file
       update_test_config_file $device_type distro-feature "mender-grub" \
@@ -474,10 +499,8 @@ do_install_bootloader_to_mender_disk_image() {
     "raspberrypi3")
       stage_5_args="-m $mender_disk_image -d $device_type -b ${bootloader_toolchain} $keep"
       eval set -- " ${stage_5_args}"
-      export -f create_device_maps
-      export -f detach_device_maps
-      export -f mount_mender_disk
-      ${tool_dir}/rpi3-convert-stage-5.sh ${stage_5_args}
+      ${tool_dir}/rpi3-convert-stage-5.sh ${stage_5_args}|| ret=$?
+      [[ $ret -ne 0 ]] && { log "\nInstalling Bootloader failed."; return $ret; }
 
       # Update test configuration file
       update_test_config_file $device_type mount-location "\/uboot"
@@ -488,35 +511,38 @@ do_install_bootloader_to_mender_disk_image() {
 }
 
 do_mender_disk_image_to_artifact() {
+  log "$step/$total Creating Mender Artifact..."
+  ((step++))
+
   if [ -z "${mender_disk_image}" ]; then
-    echo "Mender disk image not set. Aborting."
-    exit 1
+    log "Mender disk image not set. Aborting."
+    return 1
   fi
 
   if [ -z "${device_type}" ]; then
-    echo "Target device_type name not set. Aborting."
-    exit 1
+    log "Target device_type name not set. Aborting."
+    return 1
   fi
 
   if [ -z "${artifact_name}" ]; then
-    echo "Artifact name not set. Aborting."
-    exit 1
+    log "Artifact name not set. Aborting."
+    return 1
   fi
 
   if [ -z "${rootfs_partition_id}" ]; then
-    echo "Rootfs partition id not set - 'primary' will be used by default."
+    log "\tRootfs partition id not set - 'primary' will be used by default."
     rootfs_partition_id="primary"
   fi
 
   local supported=$(echo ${supported_devices[@]} | grep -o $device_type | wc -w)
 
   [[ $supported -eq 0 ]] && \
-      { echo "Error: incorrect device type. Aborting."; return 1; }
+      { log "Error: incorrect device type. Aborting."; return 1; }
 
   inarray=$(echo ${rootfs_partition_ids[@]} | grep -o $rootfs_partition_id | wc -w)
 
   [[ $inarray -eq 0 ]] && \
-      { echo "Error: invalid rootfs partition id provided. Aborting."; return 1; }
+      { log "Error: invalid rootfs partition id provided. Aborting."; return 1; }
 
   local count=
   local bootstart=
@@ -531,7 +557,7 @@ do_mender_disk_image_to_artifact() {
                        rootfs_a_size rootfs_b_start rootfs_b_size
   ret=$?
   [[ $ret -ne 0 ]] && \
-      { echo "Error: cannot validate Mender disk image. Aborting."; return 1; }
+      { log "Error: cannot validate Mender disk image. Aborting."; return 1; }
 
   # Check if device type matches.
   create_device_maps $mender_disk_image mender_disk_mappings
@@ -541,12 +567,12 @@ do_mender_disk_image_to_artifact() {
   mender_device_type=$( cat $sdimg_data_dir/mender/device_type | sed 's/[^=].*=//' )
 
   if [ "$mender_device_type" != "$device_type" ]; then
-    echo "Error: device types of Mender artifact & Mender not matching. Aborting."
+    log "Error: device types of Mender artifact & Mender not matching. Aborting."
     ret=1
   fi
 
   if ! [ -x "$(command -v mender-artifact)" ]; then
-    echo "Error: mender-artifact not found in PATH. Aborting."
+    log "Error: mender-artifact not found in PATH. Aborting."
     ret=1
   fi
 
@@ -571,14 +597,16 @@ do_mender_disk_image_to_artifact() {
     extract_file_from_image $mender_disk_image $prootfs_start \
                             $prootfs_size $mender_rootfs_basename
 
-    fsck.ext4 -fp $mender_rootfs_image
+    fsck.ext4 -fp $mender_rootfs_image &> /dev/null || ret=$?
+    [[ $ret -ne 0 ]] && \
+        { log "Error: checking $mender_rootfs_basename file system failed. Aborting."; }
 
     # Find first available loopback device.
     loopdevice=($(sudo losetup -f || ret=$?))
+    [[ $ret -ne 0 ]] && \
+        { log "Error: cannot find an unused loop device. Aborting."; }
 
-    if [ $ret -ne 0 ]; then
-      echo "Error: cannot find an unused loop device. Aborting."
-    else
+    if [ $ret -eq 0 ]; then
       #Mount extracted ext4 partition to verify 'artifact_info' file content.
       sudo losetup $loopdevice ${mender_rootfs_image}
       rootfs_mountpoint=${output_dir}/mnt/${rootfs_partition_id}
@@ -595,7 +623,7 @@ do_mender_disk_image_to_artifact() {
       # Note: expected Mender Artifact name follows the scheme:
       # mender-<device_name>-<artifact_name>.mender.
       mender_artifact=${output_dir}/${mender_disk_filename}.mender
-      echo "Writing Mender artifact to: ${mender_artifact}"
+      log "\tWriting Mender artifact to: ${mender_artifact}"
 
       #Create Mender artifact
       mender-artifact write rootfs-image \
@@ -606,8 +634,8 @@ do_mender_disk_image_to_artifact() {
 
       ret=$?
       [[ $ret -eq 0 ]] && \
-        { echo "Writing Mender artifact to ${mender_artifact} succeeded."; } || \
-        { echo "Writing Mender artifact to ${mender_artifact} failed."; }
+        { log "\tCreating Mender Artifact succeeded."; } || \
+        { log "\tCreating Mender Artifact failed."; }
     fi
   fi
 
@@ -649,6 +677,14 @@ PARAMS=""
 # Load necessary functions.
 source ${tool_dir}/mender-convert-functions.sh
 
+export -f create_device_maps
+export -f detach_device_maps
+export -f mount_mender_disk
+export -f log
+export -f logsetup
+
+logsetup
+
 while (( "$#" )); do
   case "$1" in
     -p | --rootfs-partition-id)
@@ -712,7 +748,7 @@ while (( "$#" )); do
       break
       ;;
     -*)
-      echo "Error: unsupported option $1" >&2
+      log "Error: unsupported option $1"
       exit 1
       ;;
     *)
@@ -723,7 +759,7 @@ while (( "$#" )); do
 done
 
 [ -z "${data_part_size_mb}" ] && \
-    { echo "Default 'data' partition size set to 128MB"; data_part_size_mb=128; }
+    { log "Default 'data' partition size set to 128MB"; data_part_size_mb=128; }
 
 eval set -- "$PARAMS"
 
@@ -732,42 +768,51 @@ sudo true
 
 case "$1" in
   raw-disk-image-shrink-rootfs)
+    total=1
     do_raw_disk_image_shrink_rootfs || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "The rootfs partition in the raw disk image has been shrinked successfully!"
-    echo "You can now convert the output raw disk image ($raw_disk_image) to a Mender disk image."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "The rootfs partition in the raw disk image has been shrinked successfully!"
+    log "You can now convert the output raw disk image\n\t$raw_disk_image\
+         \nto a Mender disk image."
     ;;
   raw-disk-image-create-partitions)
+    total=6
     do_raw_disk_image_create_partitions || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "A new Mender disk image with partition layout to support Mender has been successfully created!"
-    echo "You can find the output Mender disk image at ${mender_disk_image}."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "A new Mender disk image with partition layout to support Mender has been successfully created!"
+    log "You can find the output Mender disk image at:\n\t${mender_disk_image}."
     ;;
   install-mender-to-mender-disk-image)
+    total=1
     do_install_mender_to_mender_disk_image || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "The Mender client has been successfully installed to the Mender disk image."
-    echo "You can find the output Mender disk image at ${mender_disk_image}."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "The Mender client has been successfully installed to the Mender disk image."
+    log "You can find the output Mender disk image at:\n\t${mender_disk_image}."
     ;;
   install-bootloader-to-mender-disk-image)
+    total=1
     do_install_bootloader_to_mender_disk_image || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "A bootloader configuration supporting dual A/B rootfs updates has been installed to the Mender disk image!"
-    echo "You can find the output Mender disk image at ${mender_disk_image}."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "A bootloader configuration supporting dual A/B rootfs updates has been installed to the Mender disk image!"
+    log "You can find the output Mender disk image at:\n\t${mender_disk_image}."
     ;;
   mender-disk-image-to-artifact)
+    total=1
     do_mender_disk_image_to_artifact || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "A Mender Artifact has been successfully extracted from your Mender disk image!"
-    echo "You can find the Mender Artifact at $mender_artifact and use it to deploy updates."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "A Mender Artifact has been successfully extracted from your Mender disk image!"
+    log "You can find the Mender Artifact at:\n\t$mender_artifact\nand use it to deploy updates."
     ;;
   from-raw-disk-image)
+    total=9
     do_from_raw_disk_image || rc=$?
-    [[ $rc -ne 0 ]] && { exit 1; }
-    echo "Conversion complete!"
-    echo "The Mender disk image you can provision your device storage with is at ${mender_disk_image}."
-    echo "The Mender root file system partition is at ${mender_rootfs_image}."
-    echo "The Mender Artifact you can upload to your Mender server to deploy to your devices is at ${mender_artifact}."
+    [[ $rc -ne 0 ]] && { log "Check $build_log for details."; exit 1; }
+    log "Conversion complete!"
+    log "The Mender disk image you can provision your device storage with is at:\
+         \n\t${mender_disk_image}."
+    log "The Mender root file system partition is at:\n\t${mender_rootfs_image}."
+    log "The Mender Artifact you can upload to your Mender server to deploy to your devices is at:\
+         \n\t${mender_artifact}."
     ;;
   *)
     show_help
diff --git a/mender-convert-functions.sh b/mender-convert-functions.sh
index a39fa2c..1b84470 100755
--- a/mender-convert-functions.sh
+++ b/mender-convert-functions.sh
@@ -15,6 +15,7 @@ declare -a raw_disk_partitions=("boot" "rootfs")
 tool_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 files_dir=${tool_dir}/files
 output_dir=${tool_dir}/output
+build_log=${output_dir}/build.log
 
 embedded_base_dir=$output_dir/embedded
 sdimg_base_dir=$output_dir/sdimg
@@ -26,6 +27,16 @@ sdimg_primary_dir=$sdimg_base_dir/primary
 sdimg_secondary_dir=$sdimg_base_dir/secondary
 sdimg_data_dir=$sdimg_base_dir/data
 
+logsetup() {
+  echo -n "" > $build_log
+  exec > >(tee -a $build_log)
+  exec 2>&1
+}
+
+log() {
+  echo -e "$*"
+}
+
 # Takes following arguments:
 #
 #  $1 -relative file path
@@ -51,7 +62,7 @@ get_part_number_from_device() {
       echo ${1##*[0-9]p}
       ;;
     *)
-      echo "Could not determine partition number from $1"
+      log "Could not determine partition number from $1"
       exit 1
       ;;
   esac
@@ -67,7 +78,7 @@ create_single_disk_partition_table() {
   local bootstart=$2
   local stopsector=$(( $3 - 1 ))
 
-  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk $device
+  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk $device &> /dev/null
 	d # delete partition
 	n # new partition
 	p # primary partition
@@ -90,7 +101,7 @@ create_double_disk_partition_table() {
   local rootfsstart=$2
   local rootfsstop=$(( $3 - 1 ))
 
-  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk $device
+  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk $device &> /dev/null
 	d # delete partition
 	2
 	n
@@ -164,7 +175,7 @@ get_image_info() {
   eval $rvar_rootfssize="'$lsecondpartsize'"
 
   [[ $lcount -gt 2 ]] && \
-      { echo "Unsupported type of source image. Aborting."; return 1; } || \
+      { log "Unsupported type of source image. Aborting."; return 1; } || \
       { return 0; }
 }
 
@@ -196,7 +207,7 @@ get_mender_disk_info() {
   local lcount=${#lparts[@]}
 
   if [[ $lcount -ne 4 ]]; then
-    echo "Error: invalid Mender disk image. Aborting."
+    log "Error: invalid Mender disk image. Aborting."
     return 1
   else
     local lsectorsize=($(echo "${lfdisk}" | grep '^Sector' | cut -d' ' -f4))
@@ -255,7 +266,7 @@ align_partition_size() {
 #  $3 - boot partition size (in sectors)
 #  $4 - root filesystem partition size (in sectors)
 #  $5 - sector size (in bytes)
-#  $6 - image type
+#  $6 - number of detected partitions
 analyse_raw_disk_image() {
   local image=$1
   local count=
@@ -270,21 +281,18 @@ analyse_raw_disk_image() {
   local rvar_bootsize=$3
   local rvar_rootfssize=$4
   local rvar_sectorsize=$5
-  local rvar_imagetype=$6
+  local rvar_partitions=$6
 
   get_image_info $image count sectorsize bootstart bootsize \
           rootfsstart rootfssize bootflag
 
   [[ $? -ne 0 ]] && \
-      { echo "Error: invalid/unsupported raw_disk image. Aborting."; exit 1; }
+      { log "Error: invalid/unsupported raw disk image. Aborting."; exit 1; }
 
   if [[ $count -eq 1 ]]; then
-    echo -e "\nDetected single partition raw_disk image."
     rootfssize=$bootsize
     # Default size of the boot partition: 16MiB.
     bootsize=$(( ($partition_alignment * 2) / $sectorsize ))
-  elif [[ $count -eq 2 ]]; then
-    echo -e "\nDetected multipartition ($count) raw_disk image."
   fi
 
   # Boot partition storage offset is defined from the top down.
@@ -297,13 +305,7 @@ analyse_raw_disk_image() {
   eval $rvar_bootsize="'$bootsize'"
   eval $rvar_rootfssize="'$rootfssize'"
   eval $rvar_sectorsize="'$sectorsize'"
-  eval $rvar_imagetype="'$count'"
-
-  echo -e "\nEmbedded image processing summary:\
-           \nboot part start sector: ${bootstart}\
-           \nboot part size (sectors): ${bootsize}\
-           \nrootfs part size (sectors): ${rootfssize}\
-           \nsector size (bytes): ${sectorsize}\n"
+  eval $rvar_partitions="'$count'"
 }
 
 # Takes following arguments:
@@ -336,7 +338,7 @@ calculate_mender_disk_size() {
 #
 #  $1 - raw disk image
 unmount_partitions() {
-  echo "1. Check if device is mounted..."
+  log "Check if device is mounted..."
   is_mounted=`grep ${1} /proc/self/mounts | wc -l`
   if [ ${is_mounted} -ne 0 ]; then
     sudo umount ${1}?*
@@ -347,7 +349,7 @@ unmount_partitions() {
 #
 #  $1 - raw disk image
 erase_filesystem() {
-  echo "2. Erase filesystem..."
+  log "Erase filesystem..."
   sudo wipefs --all --force ${1}?*
   sudo dd if=/dev/zero of=${1} bs=1M count=100
 }
@@ -362,8 +364,7 @@ create_mender_disk() {
   local bs=$(( 1024*1024 ))
   local count=$(( ${lsize} / ${bs} ))
 
-  echo -e "\nWriting $lsize bytes to Mender disk image..."
-  dd if=/dev/zero of=${lfile} bs=${bs} count=${count}
+  dd if=/dev/zero of=${lfile} bs=${bs} count=${count}>> "$build_log" 2>&1
 }
 
 # Takes following arguments:
@@ -398,11 +399,7 @@ format_mender_disk() {
   data_start=$(( ${secondary_start} + ${rootfs_size} + 1 ))
   data_offset=$(( ${6} - 1 ))
 
-  echo $3 ${pboot_offset} $primary_start $secondary_start $data_start $data_offset
-
-  echo -e "\nFormatting Mender disk image..."
-
-  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk ${lfile}
+  sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | sudo fdisk ${lfile} &> /dev/null
 	o # clear the in memory partition table
 	x
 	h
@@ -438,6 +435,7 @@ format_mender_disk() {
 	w # write the partition table
 	q # and we're done
 EOF
+  log "\tChanges in partition table applied."
 }
 
 # Takes following arguments:
@@ -457,7 +455,7 @@ verify_mender_disk() {
   local no_of_parts=${#partitions[@]}
 
   [[ $no_of_parts -eq 4 ]] || \
-      { echo "Error: incorrect number of partitions: $no_of_parts. Aborting."; return 1; }
+      { log "Error: incorrect number of partitions: $no_of_parts. Aborting."; return 1; }
 
   eval $rvar_no_of_parts=="'$no_of_parts='"
 
@@ -474,16 +472,13 @@ create_device_maps() {
   if [[ -n "$1" ]]; then
     mapfile -t mappings < <( sudo kpartx -v -a $1 | grep 'loop' | cut -d' ' -f3 )
     [[ ${#mappings[@]} -eq 0 ]] \
-        && { echo "Error: partition mappings failed. Aborting."; exit 1; } \
-        || { echo "Mapped ${#mappings[@]} partition(s)."; }
+        && { log "Error: partition mappings failed. Aborting."; exit 1; }
   else
-    echo "Error: no device passed. Aborting."
+    log "Error: no device passed. Aborting."
     exit 1
   fi
 
   sudo partprobe /dev/${mappings[0]%p*}
-
-  echo "Mapper device: ${mappings[0]%p*}"
 }
 
 # Takes following arguments:
@@ -492,7 +487,7 @@ create_device_maps() {
 detach_device_maps() {
   local mappings=($@)
 
-  [ ${#mappings[@]} -eq 0 ] && { echo "Nothing to detach."; return; }
+  [ ${#mappings[@]} -eq 0 ] && { log "\tPartition mappings cleaned."; return; }
 
   local mapper=${mappings[0]%p*}
 
@@ -515,19 +510,20 @@ detach_device_maps() {
 #  $1 - partition mappings holder
 make_mender_disk_filesystem() {
   local mappings=($@)
-  echo -e "\nCreating filesystem for ${#mappings[@]} partitions..."
 
   for mapping in ${mappings[@]}
   do
     map_dev=/dev/mapper/"$mapping"
     part_no=$(get_part_number_from_device $map_dev)
 
-    echo -e "\nFormatting partition: ${part_no}..."
+    label=${mender_disk_partitions[${part_no} - 1]}
 
     if [[ part_no -eq 1 ]]; then
-      sudo mkfs.vfat -n ${mender_disk_partitions[${part_no} - 1]} $map_dev
+      log "\tCreating MS-DOS filesystem for '$label' partition."
+      sudo mkfs.vfat -n ${label} $map_dev >> "$build_log" 2>&1
     else
-      sudo mkfs.ext4 -L ${mender_disk_partitions[${part_no} - 1]} $map_dev
+      log "\tCreating ext4 filesystem for '$label' partition."
+      sudo mkfs.ext4 -L ${label} $map_dev >> "$build_log" 2>&1
     fi
   done
 }
@@ -573,12 +569,11 @@ mount_mender_disk() {
 #
 #  $1 - device type
 set_fstab() {
-  echo -e "\nSetting fstab..."
   local mountpoint=
   local device_type=$1
   local sysconfdir="$sdimg_primary_dir/etc"
 
-  [ ! -d "${sysconfdir}" ] && { echo "Error: cannot find rootfs config dir."; exit 1; }
+  [ ! -d "${sysconfdir}" ] && { log "Error: cannot find rootfs config dir."; exit 1; }
 
   # Erase/create the fstab file.
   sudo install -b -m 644 /dev/null ${sysconfdir}/fstab
@@ -609,6 +604,8 @@ set_fstab() {
 	/dev/mmcblk0p1   $mountpoint          auto       defaults,sync    0  0
 	/dev/mmcblk0p4   /data                auto       defaults         0  0
 	EOF"
+
+  log "\tDone."
 }
 
 # Takes following arguments
@@ -618,11 +615,11 @@ set_fstab() {
 #  $3 - size (in 512 blocks)
 
 extract_file_from_image() {
-    local cmd="dd if=$1 of=${output_dir}/$4 skip=$2 bs=512 count=$3 status=progress"
+  local cmd="dd if=$1 of=${output_dir}/$4 skip=$2 bs=512 count=$3"
 
-    echo "Running command:"
-    echo "    ${cmd}"
-    $(${cmd})
+  [ "${4##*.}" == "ext4" ] && { log "\tStoring data in $4 root file system image."; } \
+                           || { log "\tStoring data in $4 disk image."; }
+  $(${cmd}>> "$build_log" 2>&1)
 }
 
 # Takes following arguments
@@ -666,7 +663,7 @@ update_test_config_file() {
   local device_type=$1
 
   [ ! -f "${files_dir}/${device_type}_variables.cfg" ] && \
-      { echo "Error: test configuration file '${device_type}_variables.cfg' not found. Aborting."; return 1; }
+      { log "Error: test configuration file '${device_type}_variables.cfg' not found. Aborting."; return 1; }
 
   shift
 
diff --git a/rpi3-convert-stage-2.sh b/rpi3-convert-stage-2.sh
index d6a2078..57f5f4f 100755
--- a/rpi3-convert-stage-2.sh
+++ b/rpi3-convert-stage-2.sh
@@ -2,23 +2,24 @@
 
 output_dir=$1
 boot_mapping=$2
+build_log=$output_dir/build.log
 
 [ ! -f $output_dir/boot.vfat ] && \
-    { echo "Error: extracted boot partition not found. Aborting."; exit 1; }
+    { log "Error: extracted boot partition not found. Aborting."; exit 1; }
 
 # Make a copy of Linux kernel arguments and modify.
-mcopy -o -i ${output_dir}/boot.vfat -s ::cmdline.txt ${output_dir}/cmdline.txt
+mcopy -on -i ${output_dir}/boot.vfat -s ::cmdline.txt ${output_dir}/cmdline.txt
 sed -i 's/\b[ ]root=[^ ]*/ root=\/dev\/mmcblk0p2/' ${output_dir}/cmdline.txt
 sed -i 's/\b[ ]console=tty1//' ${output_dir}/cmdline.txt
 # Update Linux kernel command arguments with our custom configuration
 mcopy -o -i ${output_dir}/boot.vfat -s ${output_dir}/cmdline.txt ::cmdline.txt
 
-mcopy -i ${output_dir}/boot.vfat -s ::config.txt ${output_dir}/config.txt
+mcopy -on -i ${output_dir}/boot.vfat -s ::config.txt ${output_dir}/config.txt
 echo -e '\nenable_uart=1\n' >> ${output_dir}/config.txt
 mcopy -o -i ${output_dir}/boot.vfat -s ${output_dir}/config.txt ::config.txt
 
-sudo dd if=${output_dir}/boot.vfat of=/dev/mapper/${boot_mapping} bs=1M
+sudo dd if=${output_dir}/boot.vfat of=/dev/mapper/${boot_mapping} bs=1M >> "$build_log" 2>&1
 
-echo -e "\nStage done."
+log "\tDone."
 
 exit 0
diff --git a/rpi3-convert-stage-3.sh b/rpi3-convert-stage-3.sh
index b3044f0..763be39 100755
--- a/rpi3-convert-stage-3.sh
+++ b/rpi3-convert-stage-3.sh
@@ -2,15 +2,16 @@
 
 output_dir=$1
 rootfs_mapping=$2
+build_log=$output_dir/build.log
 
 [ ! -f ${output_dir}/rootfs.img ] && \
-    { echo "Error: extracted rootfs partition not found. Aborting."; exit 1; }
+    { log "Error: extracted rootfs partition not found. Aborting."; exit 1; }
 
-sudo dd if=${output_dir}/rootfs.img of=/dev/mapper/${rootfs_mapping} bs=8M
+sudo dd if=${output_dir}/rootfs.img of=/dev/mapper/${rootfs_mapping} bs=8M >> "$build_log" 2>&1
 
 # dd sets the original label, make sure label follows Mender naming convention.
 sudo e2label /dev/mapper/${rootfs_mapping} "primary"
 
-echo -e "\nStage done."
+log "\tDone."
 
 exit 0
diff --git a/rpi3-convert-stage-5.sh b/rpi3-convert-stage-5.sh
index 57b5e3b..d393716 100755
--- a/rpi3-convert-stage-5.sh
+++ b/rpi3-convert-stage-5.sh
@@ -23,7 +23,6 @@ bin_dir_pi=${bin_base_dir}/raspberrypi
 sdimg_base_dir=$output_dir/sdimg
 GCC_VERSION="6.3.1"
 
-echo "Running: $(basename $0)"
 declare -a mender_disk_mappings
 declare -a mender_disk_partitions=("boot" "primary" "secondary" "data")
 
@@ -46,19 +45,20 @@ build_uboot_files() {
 
   mkdir -p $bin_dir_pi
 
-  echo -e "Building U-Boot related files..."
+  log "\tBuilding U-Boot related files."
 
   if [ ! -d $uboot_repo_vc_dir ]; then
-    git clone https://github.com/mendersoftware/uboot-mender.git -b $branch
+    git clone https://github.com/mendersoftware/uboot-mender.git -b $branch >> "$build_log" 2>&1
   fi
 
   cd $uboot_dir
 
-  git checkout $commit
+  git checkout $commit >> "$build_log" 2>&1
 
-  make --quiet distclean
-  make --quiet rpi_3_32b_defconfig && make --quiet
-  make envtools
+  make --quiet distclean >> "$build_log"
+  make --quiet rpi_3_32b_defconfig >> "$build_log" 2>&1
+  make --quiet >> "$build_log" 2>&1
+  make --quiet envtools >> "$build_log" 2>&1
 
   cat<<-'EOF' >boot.cmd
 	fdt addr ${fdt_addr} && fdt get value bootargs /chosen bootargs
@@ -70,11 +70,11 @@ build_uboot_files() {
 	EOF
 
   if [ ! -e $uboot_dir/tools/mkimage ]; then
-    echo "Error: cannot build U-Boot. Aborting"
+    log "Error: cannot build U-Boot. Aborting"
     return 1
   fi
 
-  $uboot_dir/tools/mkimage -A arm -T script -C none -n "Boot script" -d "boot.cmd" boot.scr
+  $uboot_dir/tools/mkimage -A arm -T script -C none -n "Boot script" -d "boot.cmd" boot.scr >> "$build_log" 2>&1
   cp -t $bin_dir_pi $uboot_dir/boot.scr $uboot_dir/tools/env/fw_printenv $uboot_dir/u-boot.bin
 
   return 0
@@ -88,6 +88,8 @@ install_files() {
   local boot_dir=$1
   local rootfs_dir=$2
 
+  log "\tInstalling U-Boot related files."
+
   # Make a copy of Linux kernel arguments and modify.
   sudo cp ${boot_dir}/cmdline.txt ${output_dir}/cmdline.txt
 
@@ -98,9 +100,9 @@ install_files() {
   #
   # But we want it to run on our image as well to resize our data part so in
   # case it is missing, add it back to cmdline.txt
-  if ! grep "init=/usr/lib/raspi-config/init_resize.sh" ${output_dir}/cmdline.txt; then
+  if ! grep -q "init=/usr/lib/raspi-config/init_resize.sh" ${output_dir}/cmdline.txt; then
     cmdline=$(cat ${output_dir}/cmdline.txt)
-    echo "${cmdline} init=/usr/lib/raspi-config/init_resize.sh" > ${output_dir}/cmdline.txt
+    sh -c -e "echo '${cmdline} init=/usr/lib/raspi-config/init_resize.sh' >> ${output_dir}/cmdline.txt";
   fi
 
   # Update Linux kernel command arguments with our custom configuration
@@ -146,32 +148,30 @@ install_files() {
 }
 
 do_install_bootloader() {
-  echo "Setting bootloader..."
-
   if [ -z "${mender_disk_image}" ]; then
-    echo "Mender raw disk image file not set. Aborting."
+    log "Mender raw disk image file not set. Aborting."
     exit 1
   fi
 
   if [ -z "${bootloader_toolchain}" ]; then
-    echo "ARM GCC toolchain not set. Aborting."
+    log "ARM GCC toolchain not set. Aborting."
     exit 1
   fi
 
-  if [[ $(which ${bootloader_toolchain}-gcc) = 1 ]]; then
-    echo "Error: ARM GCC not found in PATH. Aborting."
+  if ! [ -x "$(command -v ${bootloader_toolchain}-gcc)" ]; then
+    log "Error: ARM GCC not found in PATH. Aborting."
     exit 1
   fi
 
   local gcc_version=$(${bootloader_toolchain}-gcc -dumpversion)
 
   if [ $(version $gcc_version) -ne $(version $GCC_VERSION) ]; then
-    echo "Error: Invalid ARM GCC version ($gcc_version). Expected $GCC_VERSION. Aborting."
+    log "Error: Invalid ARM GCC version ($gcc_version). Expected $GCC_VERSION. Aborting."
     exit 1
   fi
 
   [ ! -f $mender_disk_image ] && \
-      { echo "$mender_disk_image - file not found. Aborting."; exit 1; }
+      { log "$mender_disk_image - file not found. Aborting."; exit 1; }
 
   # Map & mount Mender compliant image.
   create_device_maps $mender_disk_image mender_disk_mappings
@@ -189,11 +189,12 @@ do_install_bootloader() {
   fi
 
   detach_device_maps ${mender_disk_mappings[@]}
+  rm -rf $sdimg_base_dir
 
   [[ $keep -eq 0 ]] && { rm -f ${output_dir}/config.txt ${output_dir}/cmdline.txt;
-     rm -rf $uboot_dir $bin_base_dir $sdimg_base_dir; }
+     rm -rf $uboot_dir $bin_base_dir; }
 
-  [[ "$rc" -ne 0 ]] && { echo -e "\nStage failure."; exit 1; } || { echo -e "\nStage done."; }
+  [[ "$rc" -ne 0 ]] && { exit 1; } || { log "\tDone."; }
 }
 
 # Conditional once we support other boards
@@ -226,7 +227,7 @@ while (( "$#" )); do
       break
       ;;
     -*)
-      echo "Error: unsupported option $1" >&2
+      log "Error: unsupported option $1"
       exit 1
       ;;
     *)