Add --minversion option to vbutil_kernel to check for rollback.

BUG=chrome-os-partner:3309
TEST=manual:

1. Extract a kernel partition from an image, for example, using
unpack_partitions.sh.  Or if running this on a device, use /dev/sda2
or /dev/sda4 for the kernel filename.

2. vbutil_kernel --verify part_2

3. Note the data key version and kernel version printed.  For example,

  Data key version:    1
  Kernel version:      3

4. Test specifying the same version.  This should succeed.

   vbutil_kernel --verify part_2 --minversion 0x00010003

5. Test specifying a higher data key version.  This should fail with a
data key version error.

   vbutil_kernel --verify part_2 --minversion 0x00020003

6. Test specifying a higher kernel version.  This should fail with a
kernel version error.

   vbutil_kernel --verify part_2 --minversion 0x00010004

Change-Id: I7b69041cf41527fc59ad29995135f30d9f496fac
Reviewed-on: http://gerrit.chromium.org/gerrit/792
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Tested-by: Randall Spangler <rspangler@chromium.org>
1 file changed