all: app.bin : to create binary output file .bin and and executable and linkable file .elf

make crt.o to compile startup code

make main.o: to compile main.c

make app.elf to create .elf output file

Get board info st-info --probe

Read flash st-flash read ./saved.img 0x8000000 0x1000

Write flash st-flash write ./saved.img 0x8000000

Erase chip st-flash erase