MSP-EXP430F5438: Flashing tool doesn't recognise the entire flash size for code thus burns only part of the code

Part Number:MSP-EXP430F5438

I am trying to run RIOT-OS on MSP-EXP430F5438 which has Flash size of 256KB and RAM of 16KB. The code that I had compiled using mspgcc on Ubuntu-16.04 is of size 14KB . When I try to burn the code on the device using JTAG and using tool Uniflash or FET-Pro430 only part of the code gets flashed. It keeps saying that the code size exceeds memory on the device. How is that possible and how to resolve this? Please help.