@bsvtgc this earlier discussion details pretty much the same question you had. Basically, as I outlined above, the main SPI Flash/ROM entry point is 0x2000 0000. The “double-tap bootloader”, a specific program module for the HiFive1 board, resides at this ROM address and eventually goes to the address you question, 0x2001 0000. If you don’t have or don’t want to use the double-tap bootloader, just erase as much of the Flash as you need and link/load your code to 0x2000 0000.