cp -L /etc/resolv.conf /mnt/gentoo/etc/
mount -t proc none /mnt/gentoo/proc
mount -o bind /dev /mnt/gentoo/dev
chroot /mnt/gentoo /bin/bash
env-update
source /etc/profile

# grub
grub> root (hd0,0)
grub> setup (hd0)
grub> quit