Gentoo bootable usb

mkdosfs -F 32 /dev/sdb1
dd if=/usr/share/syslinux/mbr.bin of=/dev/sdb
mount -o loop,ro -t iso9660 /data/software/install-amd64-minimal-20120621.iso /mnt/cdrom
mount -t vfat /dev/sdb1 /mnt/usb
cp -r /mnt/cdrom/* /mnt/usb
mv /mnt/usb/isolinux/* /mnt/usb
mv /mnt/usb/isolinux.cfg /mnt/usb/syslinux.cfg
rm -rf /mnt/usb/isolinux*
syslinux /dev/sdb1
sed -i \
 -e "s:cdroot:cdroot slowusb:" \
 -e "s:kernel memtest86:kernel memtest:" \
 /mnt/usb/syslinux.cfg