I had a problem where my code wasn't running properly so I calculated the image sizes from the A & B xcl files: cc2540\cc254x_f256_imgA.xcl.
From this I calculated both images have 126,923 bytes available for each code image area. This is calculated by totaling the memory of each code space in the .xcl file.
I thought I was OK with under 123,000 bytes of code memory but, the link map had 5036 bytes of CONST memory.
In my case CODE + CONST was greater than the 126,923 bytes. BUT THERE WERE NO ERRORS OR WARNINGS FROM THE IAR LINKER! (v8.20.1)
I didn't see any options in the tools to generate link errors from memory space violations. I've since trimmed some features out of my code to get it under the limit and now everything works fine.