1, download uboot
ftp://ftp.denx.de/pub/u-boot/
2, compile uboot
make vexpress_ca9x4_config
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabi-
make vexpress_ca9x4_config
make
3, test uboot on qemu
qemu-system-arm -M vexpress-a9 -serial stdio -kernel u-boot
