Well, actually, it is pretty straightforward.
You just need to load the application ELF file in RAM with OpenOCD (+some initializations coming from the sflash_write TCL script).
After all, it's what the tiny bootloader does.
You still may need to download DCT first (we manage to stub the access to avoid this soon).
Now, the application is loaded and reset in less than 3 seconds (even less if you keep the OpenOCD session open), instead of 25 seconds when using flash.
I could post the script here if someone is interested, but I would prefer that it comes from the Cypress team to avoid mistakes.
