Method of Second Bootloader Program Update Based on AVP32F335

This article designs a second bootloader based on AVP32F335 MCU, the second bootloader can be used to IAP via CAN bus. AVP32F335 is configured to start with on-chip FLASH, after the chip is powered on, the second bootloader at the specified location of on-chip FLASH start up and control the chip. The second bootloader requests the user app bin file from the upper computer using the communication protocol and burns it to the specified location of on-chip FLASH, and then jumps to the entrance of the user app. This article introduces in detail the chip startup process, the verification of the user app program, the communication protocol between the second bootloader and the upper computer, and the jump procedure of the user app. The test results illustrate that this method is simple to implement, stable, reliable.