What does this bootloader firmware do? - majbthrd/pic16f1454-bootloader GitHub Wiki

A bootloader is a piece of firmware that is programmed into the part FIRST. After the bootloader has been programmed the bootloader can be used to program (or reprogram) the part with an application of choice.

The bootloader occupies some of the microcontroller flash memory; the downloaded application can use any and all of the remaining flash memory.

A bootloader does NOT run concurrently with the user application. When the microcontroller boots, the execution starts with the bootloader. The bootloader then voluntarily transfers execution to the user application.

The first programming of the part with the pic16f1454-bootloader can be done by someone who has a PIC programmer. The subsequent programming of the application should be possible to be done by anyone with a PC running the download-tool provided in the Source section of this web site.

What makes this bootloader more useful than other existing bootloaders for the PIC16F145x is that once the PIC has been programmed with pic16f1454-bootloader, it doesn't need a serial adapter or a programmer to reprogrammed. You can download an application of your choice directly from a PC over USB.