1.2 I2C Bootloader

The I2C bootloader Library can be used to upgrade firmware on a target device without the need for an external programmer or debugger.

Features

  • Supported Only on CortexM0+ and CortexM4 based Devices

  • Uses Harmony 3 I2C PLIB to communicate resulting in smaller bootloader size

  • Supports Fail Safe update

  • Takes Binary File as input

  • Receives Binary from an I2C Embedded Host Device

Running From SRAM (For SAM Devices)

  • Has capability to self update as it is running from SRAM

bootloader_ram_layout

  • At reset the bootloader Reset handler copies the entire bootloader firmware into SRAM from Start location and start executing from SRAM

  • Once the application is called from bootloader, applications startup code takes control over SRAM and starts executing

I2C Bootloader Block Diagram

i2c_bootloader_block_diagram

  • I2C Event Processor Task:

    • This task is responsible for receiving data from Embedded Host through the I2C communication interface

    • The task polls and processes the I2C events.

    • Based on the event received it gives control to I2C Host Write Request or I2C Host Read Request functions

    • This task is responsible for responding to the bootloader commands received

  • I2C Host Write Request:

    • This function is responsible to handle any write requests coming from I2C host

    • It processes the commands received and notifies the status to I2C Event Process Task

    • If the command received is a Erase/Prgram/Verify command it gives control to the Flash task

  • I2C Host Read Request:

    • This function is responsible to handle any read requests coming from I2C host

    • It sends the current status to I2C host if the command received is Read Status

  • Flash Task:

    • This task is responsible to Erase/Prgram/Verify the internal flash memory with data packet received

    • The task uses the NVM peripheral library to perform the Unlock/Erase/Write Operations