# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1366756959 -7200
# Node ID 7ef64e8fcbdf5c6cee3a4f189b3de479991fbd68
# Parent  d487338fdabec6bbb48af292ceb826f99bfa4433
Added more information about installing a UML instance from installation media.
Added error messages to the UML image-making script.

diff -r d487338fdabe -r 7ef64e8fcbdf README.txt
--- a/README.txt	Mon Apr 22 23:00:48 2013 +0200
+++ b/README.txt	Wed Apr 24 00:42:39 2013 +0200
@@ -377,7 +377,9 @@
 umount installer
 
 This assumes that initrd.gz is found at the top level of the installation
-media's filesystem.
+media's filesystem. It may also be found in a directory below the top level
+such as install.386 (taking the i386 architecture as an example) on Debian
+installation media.
 
 The UML instance is then booted as follows:
 
@@ -387,6 +389,22 @@
 instance, not merely as partitions, and so installers may ask you if you would
 like to partition these devices still further.
 
+The installation media will appear as /dev/ubdc and this may need to be
+specified manually when an installer is attempting to read the installation
+media from what it thinks is a CD-ROM drive.
+
+Since the installer will most likely be designed for use on real hardware,
+various operations will be performed that will fail in a UML environment. Of
+particular importance is that of networking, and it may be necessary to
+configure networking manually during any installation process, skip any update
+steps requiring the network, and to perform additional configuration and
+updates after the installation has been carried out.
+
+Exiting an installer may be problematic since the installer may assume that
+the installation media has been ejected from the system when it is, in fact,
+still available after a reboot. To shut down the UML instance, obtain a shell
+from the installer program and issue the "halt" command.
+
 Once an installation has been performed using installation media, it should be
 possible to omit the --initrd options when running uml-do on subsequent
 occasions.
diff -r d487338fdabe -r 7ef64e8fcbdf uml-make-image
--- a/uml-make-image	Mon Apr 22 23:00:48 2013 +0200
+++ b/uml-make-image	Wed Apr 24 00:42:39 2013 +0200
@@ -54,11 +54,24 @@
 fi
 
 echo "Making the filesystem with size ${IMAGESIZE}GB..."
-dd if=/dev/zero of=$IMAGE bs=1024 count=1 seek=$(($IMAGESIZE*1024*1024-1024))
-mkfs.ext3 $IMAGE
+if dd if=/dev/zero of=$IMAGE bs=1024 count=1 seek=$(($IMAGESIZE*1024*1024-1024)) ; then
+        mkfs.ext3 $IMAGE
+else
+        cat 1>&2 <<EOF
+Unable to create an image file for the root partition.
+See the error messages above for more information.
+EOF
+        exit 1
+fi
 
 echo "Making the swap file with size ${SWAPSIZE}MB..."
-dd if=/dev/zero of=$SWAPIMAGE bs=1M count=$SWAPSIZE
+if ! dd if=/dev/zero of=$SWAPIMAGE bs=1M count=$SWAPSIZE ; then
+        cat 1>&2 <<EOF
+Unable to create an image file for the swap partition.
+See the error messages above for more information.
+EOF
+        exit 1
+fi
 
 # Image population activities.