**** Build of configuration Debug for project 21.1 ****
"C:\\ti\\ccsv6\\utils\\bin\\gmake" -k all
'Building target: 21.1.out'
'Invoking: ARM Linker'
"C:/ti/ccsv6/tools/compiler/ti-cgt-arm_5.2.5/bin/armcl" -mv7M4 --code_state=16 --float_support=FPv4SPD16 --abi=eabi -me -g --gcc --define=ccs="ccs" --define=PART_TM4C123GH6PM --diag_wrap=off --diag_warning=225 --display_error_number -z -m"21.1.map" --heap_size=0 --stack_size=512 -i"C:/ti/ccsv6/tools/compiler/ti-cgt-arm_5.2.5/lib" -i"C:/ti/ccsv6/tools/compiler/ti-cgt-arm_5.2.5/include" --reread_libs --display_error_number --diag_wrap=off --warn_sections --xml_link_info="21.1_linkInfo.xml" --rom_model -o "21.1.out" "./Nokia5110.obj" "./main.obj" "./tm4c123gh6pm_startup_ccs.obj" "../tm4c123gh6pm.cmd" -llibc.a
<Linking>
undefined first referenced
symbol in file
--------- ----------------
GPIOPinConfigure ./Nokia5110.obj
GPIOPinTypeGPIOOutput ./Nokia5110.obj
GPIOPinTypeSSI ./Nokia5110.obj
GPIOPinWrite ./Nokia5110.obj
SSIBusy ./Nokia5110.obj
SSIConfigSetExpClk ./Nokia5110.obj
SSIDataPut ./Nokia5110.obj
SSIEnable ./Nokia5110.obj
SysCtlClockGet ./Nokia5110.obj
SysCtlClockSet ./main.obj
SysCtlDelay ./Nokia5110.obj
SysCtlPeripheralEnable ./Nokia5110.obj
error #10234-D: unresolved symbols remain
error #10010: errors encountered during linking; "21.1.out" not built
>> Compilation failure
makefile:142: recipe for target '21.1.out' failed
gmake: *** [21.1.out] Error 1
gmake: Target 'all' not remade because of errors.
**** Build Finished ****
希望大神给予解答，工程已经添加在附件中了，使用的是ccs6.2，
