I am working on a custom hardware add-on to rpi2. The hardware requires the GPIO output from the pi to be programmed to a particular output value at boot time as early as possible. Is it possible to set the GPIO output value in the bootloader cmdline.txt ? (And then once the OS has booted a driver can take over to control the output value.)
If so, what is the syntax to do so.
If not, this would be a very useful upgrade to the bootloader.