X-Git-Url: http://git.grml.org/?p=grml2usb.git;a=blobdiff_plain;f=grml2usb;h=749fcd1d412ec3510afa43fb0e1da7a0ee5b0a25;hp=70d514299e07b884044965ac83821135a3162778;hb=657b880f0229f3e11d7eff07f0b285bf708606ff;hpb=8b59cb0b5c0cfaab6ea5f1ed29190d74726eb9b5

diff --git a/grml2usb b/grml2usb
index 70d5142..749fcd1 100755
--- a/grml2usb
+++ b/grml2usb
@@ -503,6 +503,12 @@ def get_partition_for_path(path):
 
 
 def check_boot_flag(device):
+    if os.path.isdir(device):
+        logging.debug(
+            "Device %s is a directory, skipping check for boot flag." % device
+        )
+        return
+
     boot_dev, x = get_device_from_partition(device)
 
     logging.info("Checking for boot flag")
@@ -748,16 +754,14 @@ def install_mbr(mbrtemplate, device, partition, ismirbsdmbr=True):
     "mbrtemplate" file, set the "partition" (0..3) active, and install the
     result back to "device".
 
-    @mbrtemplate: default MBR file
+    @mbrtemplate: default MBR file (must be a valid MBR file of at least 440
+    (or 439 if ismirbsdmbr) bytes)
 
     @device: name of a file assumed to be a hard disc (or USB stick) image, or
     something like "/dev/sdb"
 
     @partition: must be a number between 0 and 3, inclusive
 
-    @mbrtemplate: must be a valid MBR file of at least 440 (or 439 if
-    ismirbsdmbr) bytes.
-
     @ismirbsdmbr: if true then ignore the active flag, set the mirbsdmbr
     specific flag to 0/1/2/3 and set the MBR's default value accordingly. If
     false then leave the mirbsdmbr specific flag set to FFh, set all
@@ -875,6 +879,14 @@ def install_mbr(mbrtemplate, device, partition, ismirbsdmbr=True):
     proc = subprocess.Popen(["sync"])
     proc.wait()
 
+    logging.debug("Probing device via 'blockdev --rereadpt %s'", device)
+    proc = subprocess.Popen(["blockdev", "--rereadpt", device])
+    proc.wait()
+    if proc.returncode != 0:
+        raise Exception(
+            "Couldn't execute blockdev on '%s' (install util-linux?)", device
+        )
+
     set_rw(device)