hi i have read the pdf file:Embedded Linux kernel and driver developm Training lab book.pdf. at the page 7,when i boot kernel. " qemu -m 32 -kernel /lab/linux-18.104.22.168/arch/i386/boot/bzImage -append "clock=pit root=/dev/hda" -hda /lab/linux/lab1/data/linux_i386.img -boot c" i meet the information: kernel panic -not syncing:no init found. try passing init=option to kernel." then i add a console device to root filesystem: mkdir /lab/rootfs cd ....../lab1 mount -o loop data/linux_i386.img /lab/rootfs then i just copy /dev/console file to /lab/rootfs/dev.-----------though i can't find it in /lab/rootfs after i do that. and then i umount /lab/rootfs i meet the error:umount: /lab/rootfs: device is busy. Also ,i can't qeum kernel. who know the reason? explain it clearly!