How to build bootable USB key

1. Download syslinux-3.84.tar.gz

$wget http://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-3.84.tar.gz

$tar zxvf syslinux-3.84.tar.gz

2. Copy "syslinux.exe" to target(usb root)

$cp -a syslinux.exe target/...