Bootlin's Best Techniques For A Smaller Kernel + Faster Boot Times

In addition to a talk at the Embedded Linux Conference Europe on trimming the Linux boot time with systemd changes, Michael Opdenacker of embedded Linux engineering firm Bootlin presented on their techniques for not only speeding up the Linux boot time but also reductions in the kernel image size.

The techniques laid out by Opdenacker included using the U-Boot "Falcon mode" for its boot loader, an uncompressed initramfs, disable tracing, disabling sysfs, silencing the kernel output, disabling SMP during boot, simplifying the rootfs setup, and other steps.

With the examples shown during the presentation that took place in Lyon, France, Michael was able to hit a total boot time of 2.4 seconds. More details via his slide deck (PDF).