(a) image=/boot/zImage label=rtlinux-0.6 root=/dev/hda2 read-only (b) image=/boot/zImage label=rtlinux-0.6 root=/dev/hda2 read-only append="mem=31m" (c) image=/boot/zImage label=rtlinux-0.6 root=/dev/hda2 read-only append="mem=15872k"