初学CCS5.5，片子是C5509A，新建GPIO工程，编译之后显示了如下错误，我把console内容复制粘贴如下：
**** Build of configuration Debug for project GPIO ****
"D:\\Program Files\\ti\\ccsv5\\utils\\bin\\gmake" -k all
'Building target: GPIO.out'
'Invoking: C5500 Linker'
"D:/Program Files/ti/ccsv5/tools/compiler/c5500_4.4.1/bin/cl55" -v5509A --memory_model=large -g --define=CHIP_5509A --display_error_number --diag_warning=225 --ptrdiff_size=32 -z -m"GPIO.map" --stack_size=0x200 --heap_size=0x400 -i"D:/Program Files/ti/ccsv5/tools/compiler/c5500_4.4.1/lib" -i"D:/Program Files/ti/ccsv5/tools/compiler/c5500_4.4.1/include" --reread_libs --display_error_number --warn_sections --xml_link_info="GPIO_linkInfo.xml" --rom_model --sys_stacksize=0x200 -o "GPIO.out" "./gpio.obj" "../gpio.cmd" -l"libc.a"
<Linking>
warning #10247-D: creating output section "vectors" without a SECTIONS
specification
undefined first referenced
symbol in file
--------- ----------------
_CSL5509A_LIB_ ./gpio.obj
_PLL_config ./gpio.obj
__CSL_init ./gpio.obj
error #10234-D: unresolved symbols remain
>> Compilation failure
error #10010: errors encountered during linking; "GPIO.out" not built
gmake: *** [GPIO.out] Error 1
gmake: Target `all' not remade because of errors.
**** Build Finished ****
我把工程的截图发出来，请帮忙看看是不是缺少文件：
