chroot for Gentoo

Device     Boot    Start       End   Sectors   Size Id Type
/dev/sdb1             63      4159      4097     2M  4 FAT16 <32M
/dev/sdb2  *        4160   2101312   2097153     1G 83 Linux
/dev/sdb3        2101313  35655745  33554433    16G 82 Linux swap / Solaris
/dev/sdb4       35655746 488397167 452741422 215.9G 83 Linux

mount /dev/sdb4 /mnt/gentoo
mount /dev/sdb2 /mnt/gentoo/boot
mount -t proc proc /mnt/gentoo/proc
mount --rbind /sys /mnt/gentoo/sys
mount --make-rslave /mnt/gentoo/sys
mount --rbind /dev /mnt/gentoo/dev
mount --make-rslave /mnt/gentoo/dev
chroot /mnt/gentoo /bin/bash
source /etc/profile