This a simple bootloader for AT91SAM7{S,X}{64,128,256} processors. It

permits you to download new code to the device over USB. This bootrom is

installed at address 0x00000000 in the ARM, which means that it is the

first piece of code to execute after reset. At startup, it waits for

a few seconds to see if the downloader is trying to connect. If not,

then the bootloader gives up control and jumps to your program. If the

downloader is trying to connect, then the bootloader receives the new

program over USB and writes it into flash.