The firmware variants are built using different configuration overlays that modify the base functionality:
| Overlay file | Purpose | Key features |
|---|---|---|
overlay-storage-minimal.conf |
Minimal storage configuration | Reduced memory footprint with storage for one sample and immediate sending |
overlay-modem-trace-over-uart.conf and overlay-modem-trace-shmem.overlay |
Modem tracing over UART1 | UART trace backend in Kconfig and 16 KiB cpucell_cpuapp_ipc_shm_trace in SRAM |
overlay-upload-modem-traces-to-memfault.conf and overlay-upload-modem-traces-to-memfault.overlay |
Modem trace to Memfault | Memfault modem trace upload, on-flash trace partition, and trace shmem, which is mutually exclusive with the UART overlay |