spear_usbload is a tool to boot a SPEAr SOC over USB.
It is distributed under GPLv2 license.

It loads a ddr_driver (a binary that initializes the DDR) and then loads a
firmware (typically U-Boot).

Those binaries must be in uImage format.

1) Compilation

spear_usbload depends on libusb.
Compilation can be done using
./autogen.sh
./configure
make

2) Installation
make install

3) Boot over USB
Set jumpers or switches on your board to enable the USB boot.
Connect the board to your host using USB.
Check if the SOC is available
spear_usbload -s

Load over USB
spear_usbload -d /path/ddr_driver.img -f /path/firmware.img