Bootloading with NCP#

Bootloading the NCP (secondary)#

CPC supports bootloading the secondary via xmodem protocol, using CPCd as the programmer. For more details, follow the CPCd documentation.

OTA Image Distribution and Bootloading#

Connect supports OTA Broadcast and Unicast implementations. For details on them, see Bootloading and OTA with Silicon Labs Connect v3.x.

In NCP mode, currently only the Unicast implementation is supported, and it differs slightly from the SoC implementation. It is usually the Host-NCP device pair that starts distributing the image. In this case, there is no reason to first load the image to the NCP’s flash and then start the distribution. It’s much simpler to directly distribute the image from the host’s memory. This also means that you don’t need Gecko Bootloader installed on the NCP, and you don’t need to call bootloader_init or erase on the host.

To select a gbl file for distribution on the host, the load_gbl_file command can be used. Its argument is a filename, relative to the path from where the host application was started. It will return the file size, which can be used for the distribute command later on. The process of image distribution and bootloading request from this point on is the same.