OTA upgrading is an important feature for Zigbee devices. There is a detailed guide about setting up OTA server and client, AN728, but we still need to learn more about the storage settings.

Application upgrading is done by Gecko Bootloader. Gecko Bootloader can only bootload the GBL file format. Therefore, to upgrade the application image, we have to put the new image to the right place in GBL format. The detailed upgrading process is introduced in UG266.

This page will introduce the storage layout in bootloader perspective and application perspective, and also the settings of OTA storage, so that users can understand it better.

2. Storage Layout

2.1. Storage Layout in Gecko Bootloader's Perspective

2.1.1. Internal Storage

Note that the start address is the offset from the begining of the main flash.

 

2.1.2. SPI Flash Storage

Note that the start address is the offset from the beginning of the SPI flash, so it can start from 0.

 

 

2.2. Storage Layout in Application's Perspective

2.2.1. Using Slot Manager

When the plugin Slot Manager is used, the exact storage offset is determined by the Gecko Bootloader.

 

2.2.2. Using direct offset

When the plugin Slot Manager is NOT used, users need to specify the exact offset of the OTA storage. The start offset for OTA storage must match the start offset of the slot setting in Gecko Bootloader.

 

2.3. The Full Layout of Internal Flash

Besides the OTA storage, there are some other sections stored in the internal flash. When you set the offset of the OTA storage, please make sure the offset of these sections don't overlap each other. This is only applicable for internal storage. If the OTA image is stored in SPI flash, it will be OK.

There are two different flash layouts which is determined by the following setting:

 

2.3.1. Bootloader is set to Application

 

2.3.2. Bootloader is set to Local Storage

转载连接：https://github.com/Jim-tech/IoT-Developer-Boot-Camp/wiki/Zigbee-Understanding-OTA-Storage