overlay not found: kernel continues boot despite missing device tree

When a device-tree overlay is specified in /boot/config.txt but the corresponding file is missing from the boot partition, the Raspberry Pi firmware reports a failure in the kernel logs. However, the system proceeds to complete the boot sequence without halting or returning a non-zero exit code.

This silent failure creates a state where expected hardware-dependent features—such as specific network interfaces or security-related modules—remain uninitialized. Because the kernel implicitly treats the missing overlay as a non-critical error, the system may appear functional while lacking the intended security configurations or hardware-level protections.

Is there a kernel-level configuration or parameter to force a boot halt when a required device-tree overlay is missing? How can the system distinguish between a non-essential optional overlay and one critical for the system's security posture?