rootfsinstall: new -cp option to run a command before chroot

src/rootfsinstall.sh

@@ -1,3 +1,4 @@
+#!/bin/bash
 ### rootfsinstall: create partitions and fileysytems
 #
 # Based on rpi-install by: Davide Madrisan
@@ -10,6 +11,7 @@ function usage() {
    echo
    echo "Options:"
    echo "-a archive  : additional archive to unpack in rootfs root"
+   echo "-cp command : command to run before chroot. Use @ROOT@ as reference to rootfs path"
    echo "-c command  : command to run through chroot in rootfs"
    echo "-fs fstype  : filesystem type for system partition (default: ext4)"
    echo "-h hostname : set given hostname"
@@ -56,6 +58,13 @@ while [ "$1" ]; do
            CHROOTCOMMAND=$2
            shift
            ;;
+      -cp) [ "$2" ] || {
+              echo "Error: -p option requires a command string as argument; aborting."
+              exit 1
+           }
+           PRECHROOTCOMMAND=$2
+           shift
+           ;;
       -k) [ "$2" ] || {
               echo "Error: -k option requires a kernel file name as argument; aborting."
               exit 1
@@ -272,14 +281,17 @@ if [ "$USEKERNEL" ]; then
    else
       KERNELDEST=/tmp/$USEKERNEL
    fi
-   if [ -r boot/$USEKERNEL ]; then
-      cp boot/$USEKERNEL $KERNELDEST
-      if [ -e /tmp/$USEKERNEL ]; then
-         echo "Extracted kernel available as $KERNELDEST"
-      else
+   if [ -r $ROOTMP/boot/$USEKERNEL ]; then
+      cp $ROOTMP/boot/$USEKERNEL $KERNELDEST || {
          echo "ERROR: unable to find or copy kernel $USEKERNEL; aborting."
          exit 1
+      }
+      if [ -e /tmp/$USEKERNEL ]; then
+         echo "Extracted kernel is available as $KERNELDEST"
       fi
+   else
+      echo "ERROR: can't find kernel file $ROOTMP/boot/$USERKERNEL; aborting."
+      exit 1
    fi
 fi
 
@@ -296,6 +308,14 @@ if [ "$ROOTPASSWORD" ]; then
    }
 fi
 
+if [ "$PRECHROOTCOMMAND" ]; then
+   PRECHROOTCOMMAND=`echo $PRECHROOTCOMMAND | sed "s|@ROOT@|$ROOTMP|g"`
+   $PRECHROOTCOMMAND || {
+      echo "ERROR: error running pre-chroot command; aborting."
+      exit 1
+   }
+fi
+
 if [ "$CHROOTCOMMAND" ]; then
    chroot $ROOTMP $CHROOTCOMMAND || {
       echo "ERROR: error running chroot command; aborting."