I modified grub to have an additional boot option called 'CUSTOM-TEST' and booted into that.
$ ent="Ubuntu, with Linux $(uname -r)" $ cust="CUSTOM-TEST" $ sed -n -e "s/${ent}/${cust}/" \ -e "/^menuentry '${cust}'/,/}/p" \ < /boot/grub/grub.cfg | sudo tee /boot/grub/custom.cfg $ sudo sed -i 's,xen_emul_unplug=unnecessary,,' /boot/grub/custom.cfg $ sudo grub-set-default "${ent}" $ sudo grub-reboot "${cust}" $ sudo update-grub $ grep -v "^#" /boot/grub/grubenv saved_entry=CUSTOM-TEST prev_saved_entry=Ubuntu, with Linux 2.6.37-12-virtual $ cat /boot/grub/custom.cfg menuentry 'CUSTOM-TEST' --class ubuntu --class gnu-linux --class gnu --class os { recordfail set gfxpayload=$linux_gfx_mode insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root f7ac8333-d0de-4c19-b130-794dbd905a44 linux /boot/vmlinuz-2.6.37-12-virtual root=UUID=f7ac8333-d0de-4c19-b130-794dbd905a44 ro vt.handoff=7 console=ttyS0 initrd /boot/initrd.img-2.6.37-12-virtual } $ sudo reboot The above does a "boot once" into that custom test kernel, so that subsequent reboots will go back into working kernel. ** Attachment added: "console after reboot without argument" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/704022/+attachment/1796955/+files/rebooted-without-arg.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/704022 Title: xen_emul_unplug=unnecessary on kernel cmdline is required in ec2 hvm -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs