[HELP] External Flash: Nios program + Permanent data

Hello im a beginner in FPGA stuff,

After dwelling with sdcard, i gave up on the sdcard and now i am back to the flash chip on my de2-70 board to store permanent data....

Currently, i can store my program externally in that flash using flash programmer but now i want to modify the program to store permanent data in the flash for future usage....

My question is where should i change in my project plus in the software....

also when i tried to program using hal.... the program stuck at the line where the write operation takes place....

Hence i suspect that the offset im using is not right.... how can i know which offset to use when writing to flash....

Cut short...

i have my program which is flashed to cfi flash device... then i want to write my data below this program memoty address..hence i think i need the safe offset to write my data....

how can i do this?

ps: sorry if this is a repost since i really dont understand the jargons used before this...