To further reduce startup time, we looked at augmenting U-Boot Fast-Boot by modifying the SD card’s I/O operations in U-Boot when it reads the image and by shrinking the suspend image—the image of the system’s last current state, which the OS must read from external memory when the system resumes. We found that our technique in concert with these approaches can shorten startup time from the normal 27 to 30 seconds to as little as 2.3 seconds.