Internet Bootloader

The Internet Bootloader is a stand alone application allowing new application firmware to be uploaded directly into the Flash memory of a PIC18F microcontroller over an Ethernet network or the Internet. For other PIC and dsPIC architectures, third-party TCP/IP bootloaders can be obtained from http://www.brushelectronics.com/. This Internet Bootloader application implements its own private UDP/IP stack as well as a Trivial File Transfer Protocol (TFTP) server. The bootloader operates independently of the main application and cannot update itself. Safeguards are implemented internally to minimize the risk of non-recoverable failed upgrades. 

Important attributes of the Internet bootloader include:

• Self contained TFTP, UDP, IP, ARP, and Ethernet protocol handling
• Executes on Power-on Reset instead of during main application
• Waits approximately 4 seconds before starting main application
• Requires 8KB of program Flash
• Requires 0B of RAM (all used RAM is overlaid with main application)
• Requires no CPU time while executing main application
• Requires minimal or no changes to main application code and linker script
• Does not interfere with application interrupt vector locations or add interrupt latency
• Can reprogram configuration words
• Can reuse MAC and IP address provided by main application
• Client update software is already available on most computers