buildroot install

buildroot is a tool set. It contains : bootloader,busybox,kernel etc.

wiki

###Pre-installation

sudo apt-get install libncurses-dev

###install

git clone git://git.buildroot.net/buildroot
cd buildroot
make menuconfig

• Target Options -> Target Architecture(AArch64)
• Toolchain -> Toolchain type (External toolchain)
• Toolchain -> Toolchain (Linaro AArch64 14.02)
• System configuration -> Run a getty (login prompt) after boot (BR2_TARGET_GENERIC_GETTY)
• System configuration -> getty options -> TTY Port (ttyAMA0) (BR2_TARGET_GENERIC_GETTY_PORT)
• Target Packages -> Show packages that are also provided by busybox (BR2_PACKAGE_BUSYBOX_SHOW_OTHERS)
• Filesystem images -> cpio the root filesystem (for use as an initial RAM filesystem) (BR2_TARGET_ROOTFS_CPIO)

make

note: getty is a Unix program, it provides login function. wiki