Now, when we created the new configuration for the GNU compilers, CCS created a new file called tm4c123gh6pm_startup_ccs_gcc.c. This is the new startup .c file that is being used for the GNU configuration. We now need to move over our interrupt table and also add the extern definitions for the interrupt functions.
Adding the following extern lines to the begining
extern void SysTickIntHandler(void); extern void USBUARTIntHandler(void); extern void USB0DeviceIntHandler(void);
And updating the interrupt table by copy-pasting its contents from the old initalization c file.
When you launch your debug session you will find that the device comes up stuck in the fault ISR and not halted at main. According to the TI wiki this is beacuase of intended changes in Linaro GCC 4.8.4.
You can rectify this by : Specify the entry point under -e option for the linker (under Project Properties->Build->GNU Linker->Basic). This can be set to _start or ResetISR