Serial port bootloader for dsPIC33EV256GM002 and dsPIC33EP512MC202
This is a little bit of assembler that sits in the last page of flash along with some Visual Studio 2019 (free) code and source to load hex files and download, verify and boot. There is a little C++ class so that it can be included in other projects.
I use the same PC code for 16F and 18F devices and have PIC ode for the devices I use. The dsPIC33EV and dsPIC33EP devices are pretty similar so that adding other variations should be easy. The PC code reads info from the devices so most likely, there will be no changes need to the PC code to support other devices.
Only the erase size blocks that need to be modified are erased and reprogrammed so compile and reload can go pretty fast if you are lucky. The project is here: https://www.sites.google.com/site/tedrossin/home/electronics/pic#h.rdkvr4jiipdl