There are many advantages and one disadvantage in writing specific data to pROM with linker commands and accessing this data in assembly,
The advantages are:
The disadvantage is that data is not defined or accessed conventionally via C language; data is specifically flashed to pROM via the linker command file and fetched from pROM with assembly.
If you want to keep specific constant data in pROM and access it from there, you can use the linker commands to explicitly store the data in pROM and then later access the data in pROM with assembly.
The next two sections describe putting data in the pROM flash at build and run-time.