pep8 cleanups

[grml2usb.git] / grml2usb

diff --git a/grml2usb b/grml2usb
index bef2dc2..4e958b5 100755 (executable)
--- a/grml2usb
+++ b/grml2usb
@@ -40,11 +40,13 @@ GRML_FLAVOURS = set()  # which flavours are being installed?
 GRML_DEFAULT = None
 UUID = None
 SYSLINUX_LIBS = "/usr/lib/syslinux/"
+GPT_HEADER = "\x55\xaa\x45\x46\x49\x20\x50\x41\x52\x54"  # original GPT header
 
 RE_PARTITION = re.compile(r'([a-z/]*?)(\d+)$')
 RE_P_PARTITION = re.compile(r'(.*?\d+)p(\d+)$')
 RE_LOOP_DEVICE = re.compile(r'/dev/loop\d+$')
 
+
 def syslinux_warning(option, opt, value, opt_parser):
     """A helper function for printing a warning about deprecated option
     """
@@ -131,6 +133,7 @@ class CriticalException(Exception):
     @Exception: message"""
     pass
 
+
 class VerifyException(Exception):
     """Throw critical exception if there is an fatal error when verifying something.
 
@@ -286,7 +289,7 @@ def search_file(filename, search_path='/bin' + os.pathsep + '/usr/bin', lst_retu
 
         @cwd: current working directory
         """
-        return  os.path.exists(os.path.join(cwd, filename))
+        return os.path.exists(os.path.join(cwd, filename))
 
     for path in paths:
         current_dir = path
@@ -318,9 +321,13 @@ def check_boot_flag(device):
     boot_dev, x = get_device_from_partition(device)
 
     with open(boot_dev, 'r') as image:
-        data = image.read(512)
+        data = image.read(520)
         bootcode = data[440:]
-        if bootcode[6] == '\x80':
+        gpt_data = bootcode[70:80]
+
+        if gpt_data == GPT_HEADER:
+            logging.info("GPT detected, skipping bootflag check")
+        elif bootcode[6] == '\x80':
             logging.debug("bootflag is enabled")
         else:
             logging.debug("bootflag is NOT enabled")
@@ -796,8 +803,7 @@ def copy_system_files(grml_flavour, iso_mount, target):
     squashfs = search_file(grml_flavour + '.squashfs', iso_mount)
     if squashfs is None:
         logging.error("error locating squashfs file")
-        raise CriticalException("squashfs file not found"
-            ", please check that your iso is not corrupt")
+        raise CriticalException("squashfs file not found, please check that your iso is not corrupt")
     else:
         squashfs_target = target + '/live/' + grml_flavour + '/'
         execute(mkdir, squashfs_target)
@@ -1379,7 +1385,7 @@ def handle_syslinux_config(grml_flavour, target):
 
     # install main configuration only *once*, no matter how many ISOs we have:
     syslinux_config_file = open(syslinux_cfg, 'w')
-    syslinux_config_file.write("TIMEOUT 300\n")
+    syslinux_config_file.write("timeout 300\n")
     syslinux_config_file.write("include vesamenu.cfg\n")
     syslinux_config_file.close()
 
@@ -1562,7 +1568,20 @@ def handle_mbr(device):
 
     mbrcode = GRML2USB_BASE + '/mbr/mbrldr'
     if options.syslinuxmbr:
-        mbrcode = '/usr/lib/syslinux/mbr.bin'
+        mbrcode = ""
+        mbr_locations = ('/usr/lib/syslinux/mbr.bin',
+                         '/usr/share/syslinux/mbr.bin')
+        for mbrpath in mbr_locations:
+            if os.path.isfile(mbrpath):
+                mbrcode = mbrpath
+                break
+
+        if mbrcode is "":
+            str_locations = " or ".join(['"%s"' % l for l in mbr_locations])
+            logging.error('Cannot find syslinux MBR, install it at %s)',
+                          str_locations)
+            raise CriticalException("syslinux MBR  can not be found at %s."
+                                    % str_locations)
     elif options.mbrmenu:
         mbrcode = GRML2USB_BASE + '/mbr/mbrldr'