X-Git-Url: https://git.grml.org/?p=grml2usb.git;a=blobdiff_plain;f=grml2usb;h=2bb543905d31cfebb10fbf46e8543f81787acb26;hp=fc3a9055c493c0c0750894479e88c4c67717bdfb;hb=68df4a8c900486fc17138b4da1fe1f0847c45396;hpb=428b5102a56be55e3d980103a4f0207c0f650ac8

diff --git a/grml2usb b/grml2usb
index fc3a905..2bb5439 100755
--- a/grml2usb
+++ b/grml2usb
@@ -88,6 +88,21 @@ class CriticalException(Exception):
     pass
 
 
+# The following two functions help to operate on strings as
+# array (list) of bytes (octets). In Python 3000, the bytes
+# datatype will need to be used. This is intended for using
+# with manipulation of files on the octet level, like shell
+# arrays, e.g. in MBR creation.
+
+def array2string(a):
+    """Convert a list of integers [0;255] to a string."""
+    return struct.pack("%sB" % len(a), *a)
+
+def string2array(s):
+    """Convert a (bytes) string into a list of integers."""
+    return struct.unpack("%sB" % len(s), s)
+
+
 def cleanup():
     """Cleanup function to make sure there aren't any mounted devices left behind.
     """
@@ -955,6 +970,7 @@ def copy_system_files(grml_flavour, iso_mount, target):
     filesystem_module = search_file('filesystem.module', iso_mount)
     if filesystem_module is None:
         logging.critical("Fatal: filesystem.module not found")
+        raise CriticalException("error locating filesystem.module file")
     else:
         exec_rsync(filesystem_module, squashfs_target + 'filesystem.module')
 
@@ -964,12 +980,14 @@ def copy_system_files(grml_flavour, iso_mount, target):
     kernel = search_file('linux26', iso_mount)
     if kernel is None:
         logging.critical("Fatal kernel not found")
+        raise CriticalException("error locating kernel file")
     else:
         exec_rsync(kernel, release_target + '/linux26')
 
     initrd = search_file('initrd.gz', iso_mount)
     if initrd is None:
         logging.critical("Fatal: initrd not found")
+        raise CriticalException("error locating initrd file")
     else:
         exec_rsync(initrd, release_target + '/initrd.gz')