grub2 doesn’t allow passing arguments to ‘modules’ in multiboot environment

This seamingly reasonable entry will fail to boot (waiting for root filesystem, iirc):

menuentry “Xen 3.2″ {
multiboot (hd0,1)/xen-3.2-1-amd64.gz dom0_mem=256M
module (hd0,1)/vmlinuz-2.6.18-5-xen-amd64 root=/dev/sda2 ro
module (hd0,1)/initrd.img-2.6.18-5-xen-amd64

The issue is that the arguments “root=/dev/sda2 ro” do not actually get passed to the kernel. If you’re sufficiently patient and you get dropped to a busybox shell, ‘cat /proc/cmdline’ will demonstrate this. A possible work-around if you build your own kernels is to set the kernel command line options statically at compile time. It’s the very last option under “Processor Type and Features” or whatever (don’t recall exactly).

This strikes me as a pretty crippling limitation of grub2. I hope I’m just missing something that will be obvious in hindsight.


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