Index: tools/boot/install-boot.sh
===================================================================
--- tools/boot/install-boot.sh
+++ tools/boot/install-boot.sh
@@ -134,29 +134,31 @@
     echo "Copying loader to /EFI/freebsd on ESP"
     cp "${file}" "${mntpt}/EFI/freebsd/loader.efi"
 
-    existingbootentryloaderfile=$(efibootmgr -v | grep "${mntpt}//EFI/freebsd/loader.efi")
+    if [ -z "${offline}" ]; then
+        existingbootentryloaderfile=$(efibootmgr -v | grep "${mntpt}//EFI/freebsd/loader.efi")
 
-    if [ -z "$existingbootentryloaderfile" ]; then
-        # Try again without the double forward-slash in the path
-        existingbootentryloaderfile=$(efibootmgr -v | grep "${mntpt}/EFI/freebsd/loader.efi")
-    fi
-
-    if [ -z "$existingbootentryloaderfile" ]; then
-        echo "Creating UEFI boot entry for FreeBSD"
-        efibootmgr --create --label FreeBSD --loader "${mntpt}/EFI/freebsd/loader.efi" > /dev/null
-        if [ $? -ne 0 ]; then
-            die "Failed to create new boot entry"
+        if [ -z "$existingbootentryloaderfile" ]; then
+            # Try again without the double forward-slash in the path
+            existingbootentryloaderfile=$(efibootmgr -v | grep "${mntpt}/EFI/freebsd/loader.efi")
         fi
 
-        # When creating new entries, efibootmgr doesn't mark them active, so we need to
-        # do so. It doesn't make it easy to find which entry it just added, so rely on
-        # the fact that it places the new entry first in BootOrder.
-        bootorder=$(efivar --name 8be4df61-93ca-11d2-aa0d-00e098032b8c-BootOrder --print --no-name --hex | head -1)
-        bootentry=$(echo "${bootorder}" | cut -w -f 3)$(echo "${bootorder}" | cut -w -f 2)
-        echo "Marking UEFI boot entry ${bootentry} active"
-        efibootmgr --activate "${bootentry}" > /dev/null
-    else
-        echo "Existing UEFI FreeBSD boot entry found: not creating a new one"
+        if [ -z "$existingbootentryloaderfile" ]; then
+            echo "Creating UEFI boot entry for FreeBSD"
+            efibootmgr --create --label FreeBSD --loader "${mntpt}/EFI/freebsd/loader.efi" > /dev/null
+            if [ $? -ne 0 ]; then
+                die "Failed to create new boot entry"
+            fi
+
+            # When creating new entries, efibootmgr doesn't mark them active, so we need to
+            # do so. It doesn't make it easy to find which entry it just added, so rely on
+            # the fact that it places the new entry first in BootOrder.
+            bootorder=$(efivar --name 8be4df61-93ca-11d2-aa0d-00e098032b8c-BootOrder --print --no-name --hex | head -1)
+            bootentry=$(echo "${bootorder}" | cut -w -f 3)$(echo "${bootorder}" | cut -w -f 2)
+            echo "Marking UEFI boot entry ${bootentry} active"
+            efibootmgr --activate "${bootentry}" > /dev/null
+        else
+            echo "Existing UEFI FreeBSD boot entry found: not creating a new one"
+        fi
     fi
 
     umount "${mntpt}"
@@ -362,6 +364,7 @@
 	printf ' -f fs         filesystem type: ufs or zfs\n'
 	printf ' -g geli       yes or no\n'
 	printf ' -h            this help/usage text\n'
+	printf ' -n            Operate offline: do not run efibootmgr etc.\n'
 	printf ' -o optargs    optional arguments\n'
 	printf ' -s scheme     mbr or gpt\n'
 	exit 0
@@ -372,7 +375,7 @@
 # Note: we really don't support geli boot in this script yet.
 geli=nogeli
 
-while getopts "b:d:f:g:ho:s:" opt; do
+while getopts "b:d:f:g:hno:s:" opt; do
     case "$opt" in
 	b)
 	    bios=${OPTARG}
@@ -389,6 +392,9 @@
 		*) geli=nogeli ;;
 	    esac
 	    ;;
+	n)
+	    offline=1
+	    ;;
 	o)
 	    opts=${OPTARG}
 	    ;;
Index: tools/boot/rootgen.sh
===================================================================
--- tools/boot/rootgen.sh
+++ tools/boot/rootgen.sh
@@ -27,6 +27,8 @@
 # vars should likely be conditionally set to allow better automation.
 #
 
+. $(dirname $0)/install-boot.sh
+
 cpsys() {
     src=$1
     dst=$2
@@ -116,7 +118,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -154,7 +156,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -193,7 +195,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -274,7 +276,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -315,7 +317,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -356,7 +358,7 @@
     zpool set bootfs=${pool}/ROOT/default ${pool}
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -392,7 +394,7 @@
     # end tweaks
     umount -f ${mntpt}
     geli detach ${md}p2
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -428,7 +430,7 @@
     # end tweaks
     umount -f ${mntpt}
     geli detach ${md}p2
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -465,7 +467,7 @@
     # end tweaks
     umount -f ${mntpt}
     geli detach ${md}p3
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -508,7 +510,7 @@
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
     geli detach ${md}p2
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -551,7 +553,7 @@
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
     geli detach ${md}p2
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -595,7 +597,7 @@
     zpool set autoexpand=on ${pool}
     zpool export ${pool}
     geli detach ${md}p3
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
 }
 
@@ -641,7 +643,7 @@
     kldload geom_part_vtoc8.ko
     gpart create -s VTOC8 ${md}
     gpart add -t freebsd-ufs ${md}
-    ${SRCTOP}/tools/boot/install-boot.sh -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
+    ${SRCTOP}/tools/boot/install-boot.sh -n -g ${geli} -s ${scheme} -f ${fs} -b ${bios} -d ${src} ${md}
     mdconfig -d -u ${md}
     rm -f ${src}/etc/fstab
 }