Open Source Summit + Embedded Linux Conference North America 2026

With more stringent regulations for automotive usecases, every millisecond of boot time is critical. Safety features like rear-view camera and surround view must start working quickly to meet regulations. A typical solution is to have custom boot loaders as they are often faster than U-Boot and the memory footprint of U-Boot has been increasing as device trees grow larger. However, U-Boot provides significant advantages: rich driver model, broad hardware and strong community support.

This raises an important question: how can U-Boot be made a more attractive alternative to custom RTOS bootloaders w.r.t boot time and memory footprint? The answer lies in "bootph" (boot phase) tags, which enable selective node tagging to solve the above-mentioned problems.

This session aims to cover the following:
1. Overview of U-Boot boot phases(SPL, VPL, TPL & U-Boot proper).
2. Deep dive into bootph tags: usage, meaning, and how they affect each boot phase.
3. Common pitfalls: accidentally removing SPL-required nodes, over-tagging shared peripherals, and overusing bootph-all tag.
4. A live case study demonstrating how U-Boot matched the boot time of a custom RTOS bootloader on the TI J7200 SoC.