https://docs.silabs.com/openthread/2.7.0/bootloader-user-guide-series3-and-higher/03-gecko-bootloader-operation-application-upgrade
03 Gecko Bootloader Operation Application Upgrade | Gecko Bootloader User's Guide for Series 3 and...
Gecko Bootloader User's Guide for Series 3 and Higher - 03 Gecko Bootloader Operation Application Upgrade in OpenThread (v2.7.0) | Silicon Labs Docs