diff --git a/board/common/overlay-initramfs/init b/board/common/overlay-initramfs/init
index 5869745d88..301697a9e7 100755
--- a/board/common/overlay-initramfs/init
+++ b/board/common/overlay-initramfs/init
@@ -1,18 +1,20 @@
 #!/bin/sh
 
 PATH=/bin:/sbin:/usr/bin:/usr/sbin
-DISK_TIMEOUT="10"
+DISK_TIMEOUT=10
 
 msg() {
     echo " * $1"
 }
 
+sh
+
 msg "Mounting pseudo filesystems"
 mount -t devtmpfs devtmpfs /dev
 mount -t proc proc /proc
 
 ROOT_DEV=$(cat /proc/cmdline | grep -oE 'root=[/a-z0-9]+' | cut -d '=' -f 2)
-if echo ${ROOT_DEV: -2} | grep -E 'p[0-9]' &>/dev/null; then  # e.g. /dev/mmcblk0p2
+if echo ${ROOT_DEV:-2} | grep -E 'p[0-9]' &>/dev/null; then  # e.g. /dev/mmcblk0p2
     DISK_DEV=${ROOT_DEV:0:$((${#ROOT_DEV}-2))}
     BOOT_DEV=${DISK_DEV}p1
     DATA_DEV=${DISK_DEV}p3
@@ -28,10 +30,10 @@ while true; do
     if [ ${count} -ge ${DISK_TIMEOUT} ]; then
         break
     fi
-    if [ -b ${ROOT_DEV} ]; then
+    if [[ -b ${ROOT_DEV} ]]; then
         break
     fi
-    count=$((${count} + 1))
+    count=$((count + 1))
     sleep 1
 done
 
@@ -41,15 +43,12 @@ msg "Root device is ${ROOT_DEV}"
 msg "Data device is ${DATA_DEV}"
 
 FW_DIR=/data/.fwupdate
-FW_FILE=firmware.img.gz
-FW_FILE_EXTR=firmware.img
+FW_FILE=${FW_DIR}/firmware.img.gz
+FW_FILE_EXTR=${FW_DIR}/firmware.img
 
-LEGACY_FW_DIR=/data/.firmware_update
-LEGACY_FW_FILE_EXTR=firmware
+ROOT_INFO_FILE=${FW_DIR}/root_info
 
-ROOT_INFO_FILE=root_info
-
-on_exit() {
+cleanup_on_exit() {
     msg "Switching to normal boot"
     /remove_initramfs
 
@@ -66,7 +65,7 @@ on_exit() {
     echo 'b' > /proc/sysrq-trigger
 }
 
-trap on_exit EXIT
+trap cleanup_on_exit EXIT
 
 if [ -x /prepare_initramfs ]; then
     msg "Preparing initramfs"
@@ -79,35 +78,39 @@ mount ${BOOT_DEV} /boot
 msg "Mounting data partition"
 mount ${DATA_DEV} /data
 
-if ! [ -r ${FW_DIR}/${FW_FILE_EXTR} ]; then
-    if [ -r ${LEGACY_FW_DIR}/${LEGACY_FW_FILE_EXTR} ]; then
-        msg "Detected legacy firmware path"
-        mkdir -p ${FW_DIR}
-        mv ${LEGACY_FW_DIR}/${LEGACY_FW_FILE_EXTR} ${FW_DIR}/${FW_FILE_EXTR}
-        
-        msg "Computing root partition info"
-        root_start=$(fdisk -l ${FW_DIR}/${FW_FILE_EXTR} | grep ${FW_FILE_EXTR}2 | tr -s ' ' | cut -d ' ' -f 4)
-        root_start=$((${root_start} / 2048))
-        root_size=$(fdisk -l ${FW_DIR}/${FW_FILE_EXTR} | grep ${FW_FILE_EXTR}2 | tr -s ' ' | cut -d ' ' -f 6)
-        root_size=$((${root_size} / 2048))
-        
-        echo ${root_start} ${root_size} > ${FW_DIR}/${ROOT_INFO_FILE}
-    else
-        msg "No firmware found, aborting"
-        exit 1
-    fi
+if ! [[ -r ${FW_FILE_EXTR} ]]; then
+    msg "No firmware found, aborting"
+    exit 1
 fi
 
-if ! [ -r ${FW_DIR}/${ROOT_INFO_FILE} ]; then
+if ! [[ -r ${ROOT_INFO_FILE} ]]; then
     msg "No root partition info, aborting"
     exit 1
 fi
 
 msg "Copying root image"
-root_start=$(cat ${FW_DIR}/${ROOT_INFO_FILE} | cut -d ' ' -f 1)
-root_size=$(cat ${FW_DIR}/${ROOT_INFO_FILE} | cut -d ' ' -f 2)
+root_info=$(cat ${ROOT_INFO_FILE})
+count=0
 
-dd if=${FW_DIR}/${FW_FILE_EXTR} skip=${root_start} of=${ROOT_DEV} bs=1048576 count=${root_size} || exit 1
+for i in ${root_info}; do count=$((count + 1)); done
+
+if [[ ${count} == 3 ]]; then
+    root_start=$(echo ${root_info} | cut -d ' ' -f 1)
+    root_size=$(echo ${root_info} | cut -d ' ' -f 3)
+    root_start=$((root_start / 2048))
+    root_size=$((root_size / 2048))
+
+elif [[ ${count} == 2 ]]; then
+    # compatibility with old info file format
+    root_start=$(echo ${root_info} | cut -d ' ' -f 1)
+    root_size=$(echo ${root_info} | cut -d ' ' -f 2)
+
+else
+    msg "Unrecognized root partition info file format"
+    exit 1
+fi
+
+dd if=${FW_FILE_EXTR} skip=${root_start} of=${ROOT_DEV} bs=1048576 count=${root_size} || exit 1
 
 msg "Cleaning up"
 rm -rf ${FW_DIR}
diff --git a/board/raspberrypi/cpinitramfs.sh b/board/raspberrypi/cpinitramfs.sh
index a1dd89030b..9965c2aaa6 100755
--- a/board/raspberrypi/cpinitramfs.sh
+++ b/board/raspberrypi/cpinitramfs.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
 
 cp ${IMG_DIR}/rootfs.cpio.gz ${BOARD_DIR}/initrd.gz
+cp ${IMG_DIR}/rootfs.cpio.gz ${BOARD_DIR}/fwupdater.gz  # for compatibility
 
diff --git a/board/raspberrypi3/initrd.gz b/board/raspberrypi3/initrd.gz
new file mode 100644
index 0000000000..8b729de08a
Binary files /dev/null and b/board/raspberrypi3/initrd.gz differ