Implemented 'rootoptions' and 'rootrwoptions' kernel parameters

These parameters allow to change the mount options of the read-only and
read-write filesystems via the kernel commandline.

Signed-off-by: Claudius Heine <ch@denx.de>

2 files changed, 45 insertions, 16 deletions

diff --git a/README.md b/README.md
index ec1aa07..07fb6ad 100644
--- a/README.md
+++ b/README.md
@@ -134,8 +134,12 @@ The same as before but it now starts `/bin/sh` instead of `/sbin/init`
 `root=` specifies the read-only root file system device. If this is not
 specified, the current rootfs is used.
 
-`rootfstype=` if support for the-read only file system is not build into the
-kernel, you can specify the required module name here.
+`rootfstype=` if support for the read-only file system is not build into the
+kernel, you can specify the required module name here. It will also be used in
+the mount command.
+
+`rootoptions=` specifies the mount options of the read-only file system.
+Defaults to `noatime,nodiratime`.
 
 `rootinit=` if the `init` parameter was used to specify this init script,
 `rootinit` can be used to overwrite the default (`/sbin/init`).
@@ -144,7 +148,11 @@ kernel, you can specify the required module name here.
 specified, `tmpfs` is used.
 
 `rootrwfstype=` if support for the read-write file system is not build into the
-kernel, you can specify the required module name here.
+kernel, you can specify the required module name here. It will also be used in
+the mount command.
+
+`rootrwoptions=` specifies the mount options of the read-write file system.
+Defaults to `rw,noatime,mode=755`.
 
 `rootrwreset=` set to `yes` if you want to delete all the files in the
 read-write file system prior to building the overlay root files system.
diff --git a/recipes-core/initrdscripts/files/init-readonly-rootfs-overlay-boot.sh b/recipes-core/initrdscripts/files/init-readonly-rootfs-overlay-boot.sh
index ff6a774..be62db0 100644
--- a/recipes-core/initrdscripts/files/init-readonly-rootfs-overlay-boot.sh
+++ b/recipes-core/initrdscripts/files/init-readonly-rootfs-overlay-boot.sh
@@ -18,6 +18,14 @@ ROOT_ROMOUNT="/media/rfs/ro"
 ROOT_RWMOUNT="/media/rfs/rw"
 ROOT_RWRESET="no"
 
+ROOT_ROFSTYPE=""
+ROOT_ROMOUNTOPTIONS="bind"
+ROOT_ROMOUNTOPTIONS_DEVICE="noatime,nodiratime"
+
+ROOT_RWFSTYPE=""
+ROOT_RWMOUNTOPTIONS="rw,noatime,mode=755 tmpfs"
+ROOT_RWMOUNTOPTIONS_DEVICE="rw,noatime,mode=755"
+
 early_setup() {
         mkdir -p /proc
         mkdir -p /sys
@@ -36,17 +44,23 @@ read_args() {
                         root=*)
                                 ROOT_RODEVICE=$optarg ;;
                         rootfstype=*)
+                                ROOT_ROFSTYPE="$optarg"
                                 modprobe $optarg 2> /dev/null || \
                                         log "Could not load $optarg module";;
                         rootinit=*)
                                 ROOT_ROINIT=$optarg ;;
+                        rootoptions=*)
+                                ROOT_ROMOUNTOPTIONS_DEVICE="$optarg" ;;
                         rootrw=*)
                                 ROOT_RWDEVICE=$optarg ;;
                         rootrwfstype=*)
+                                ROOT_RWFSTYPE="$optarg"
                                 modprobe $optarg 2> /dev/null || \
                                         log "Could not load $optarg module";;
                         rootrwreset=*)
                                 ROOT_RWRESET=$optarg ;;
+                        rootrwoptions=*)
+                                ROOT_RWMOUNTOPTIONS_DEVICE="$optarg" ;;
                         init=*)
                         INIT=$optarg ;;
                 esac
@@ -75,19 +89,22 @@ mount_and_boot() {
         # Build mount options for read only root file system.
         # If no read-only device was specified via kernel command line, use
         # current root file system via bind mount.
-        ROOT_ROMOUNTOPTIONS_BIND="-o bind /"
-        if [ -z "${ROOT_RODEVICE}" ]; then
-                ROOT_ROMOUNTOPTIONS="${ROOT_ROMOUNTOPTIONS_BIND}"
+        ROOT_ROMOUNTPARAMS_BIND="-o ${ROOT_ROMOUNTOPTIONS} /"
+        if [ -n "${ROOT_RODEVICE}" ]; then
+                ROOT_ROMOUNTPARAMS="-o ${ROOT_ROMOUNTOPTIONS_DEVICE} $ROOT_RODEVICE"
+                if [ -n "${ROOT_ROFSTYPE}" ]; then
+                        ROOT_ROMOUNTPARAMS="-t $ROOT_ROFSTYPE $ROOT_ROMOUNTPARAMS"
+                fi
         else
-                ROOT_ROMOUNTOPTIONS="-o noatime,nodiratime $ROOT_RODEVICE"
+                ROOT_ROMOUNTPARAMS="$ROOT_ROMOUNTPARAMS_BIND"
         fi
 
         # Mount root file system to new mount-point, if unsuccessful, try bind
         # mounting current root file system.
-        if ! $MOUNT $ROOT_ROMOUNTOPTIONS "$ROOT_ROMOUNT" 2>/dev/null && \
-                [ "x$ROOT_ROMOUNTOPTIONS_BIND" == "x$ROOT_ROMOUNTOPTIONS" ] || \
+        if ! $MOUNT $ROOT_ROMOUNTPARAMS "$ROOT_ROMOUNT" 2>/dev/null && \
+                [ "x$ROOT_ROMOUNTPARAMS_BIND" == "x$ROOT_ROMOUNTPARAMS" ] || \
                 log "Could not mount $ROOT_RODEVICE, bind mounting..." && \
-                ! $MOUNT $ROOT_ROMOUNTOPTIONS_BIND "$ROOT_ROMOUNT"; then
+                ! $MOUNT $ROOT_ROMOUNTPARAMS_BIND "$ROOT_ROMOUNT"; then
                 fatal "Could not mount read-only rootfs"
         fi
 
@@ -104,16 +121,20 @@ mount_and_boot() {
         fi
 
         # Build mount options for read write root file system.
-        # If no read-write device was specified via kernel command line, use
-        # tmpfs.
-        if [ -z "${ROOT_RWDEVICE}" ]; then
-                ROOT_RWMOUNTOPTIONS="-t tmpfs -o rw,noatime,mode=755 tmpfs"
+        # If a read-write device was specified via kernel command line, use
+        # it, otherwise default to tmpfs.
+        if [ -n "${ROOT_RWDEVICE}" ]; then
+                
+                ROOT_RWMOUNTPARAMS="-o $ROOT_RWMOUNTOPTIONS_DEVICE $ROOT_RWDEVICE"
+                if [ -n "${ROOT_RWFSTYPE}" ]; then
+                        ROOT_RWMOUNTPARAMS="-t $ROOT_RWFSTYPE $ROOT_RWMOUNTPARAMS"
+                fi
         else
-                ROOT_RWMOUNTOPTIONS="-o rw,noatime,mode=755 $ROOT_RWDEVICE"
+                ROOT_RWMOUNTPARAMS="-t tmpfs -o $ROOT_RWMOUNTOPTIONS"
         fi
 
         # Mount read-write file system into initram root file system
-        if ! $MOUNT $ROOT_RWMOUNTOPTIONS $ROOT_RWMOUNT ; then
+        if ! $MOUNT $ROOT_RWMOUNTPARAMS $ROOT_RWMOUNT ; then
                 fatal "Could not mount read-write rootfs"
         fi