Description of problem:

  When you create a livecd, llivecd-creator always adds to the parameters kernels line "ro liveimg quiet". In this quiet setting can cause problems at the start of the kernel in VMware WS (see http://wiki.centos.org/Manuals/ReleaseNotes/CentOSLiveCD5.6#head-41a02a9986009392b59145e7b999177e49af9636), and VirtualBox VM (is watching me: kernel hangs if the parameter string is quiet and the system boots properly, if quiet remove).

  Reasons:

1. See /usr/lib/python2.6/site-packages/imgcreate/kickstart.py:

def get_kernel_args(ks, default = "ro liveimg quiet"):
    if not hasattr(ks.handler.bootloader, "appendLine"):
        return default
    if ks.handler.bootloader.appendLine is None:
        return default
    return "%s %s" %(default, ks.handler.bootloader.appendLine)
    
  It can be seen that the result returned is always added to the contents of the variable default. And by default, it is "ro liveimg quiet".

2. See /usr/lib/python2.6/site-packages/imgcreate/live.py (what uses llivecd-creator):

    def _get_kernel_options(self):
        """Return a kernel options string for bootloader configuration.

        This is the hook where subclasses may specify a set of kernel options
        which should be included in the images bootloader configuration.

        A sensible default implementation is provided.

        """
        r = kickstart.get_kernel_args(self.ks)
        if os.path.exists(self._instroot + "/usr/bin/rhgb"):
            r += " rhgb"
        if os.path.exists(self._instroot + "/usr/bin/plymouth"):
            r += " rhgb"
        return r


It can be seen that the function call get_kernel_args the default option is not passed. That is, its value is used by default.

Offering: Add to llivecd-creator option allows you to specify the default option in the function get_kernel_args.