undefined first referenced symbol in file --------- ---------------- GPIOBank6Pin12PinMuxSetup ./main.obj

板子是ti官方的OMAPL138 LCDK，软件是CCS5.5，用得是TI给的例子，也就是在OMAPL138_StarterWare_1_10_04_01文件里的demoLedIf。

程序是：

#include "gpio.h"

#include "soc_C6748.h"

#include "hw_psc_C6748.h"

#include "lcdkC6748.h"

#include "demoCfg.h"

static unsigned int ledState = 0;

void LedIfConfig(void)

{GPIOBank6Pin12PinMuxSetup();

GPIODirModeSet(SOC_GPIO_0_REGS, 109, GPIO_DIR_OUTPUT);}

void LedToggle(void)

 {    

 if(ledState == 0) ledState = 1;    

 else ledState = 0;  

GPIOPinWrite(SOC_GPIO_0_REGS, 109, ledState); }

void LedOff(void)

 {  GPIOPinWrite(SOC_GPIO_0_REGS, 109, GPIO_PIN_HIGH); }

void main(void)

{

LedIfConfig();

LedToggle();

LedOff();

}

但是出现了错误：

**** Build of configuration Debug for project led3 ****

"C:\\ti\\ccsv5\\utils\\bin\\gmake" -k all
'Building file: ../main.c'
'Invoking: C6000 Compiler'
"C:/ti/ccsv5/tools/compiler/c6000_7.4.4/bin/cl6x" -mv6740 --abi=eabi -g --include_path="C:/ti/ccsv5/tools/compiler/c6000_7.4.4/include" --include_path="../include" --include_path="../include/hw" --include_path="../include/C674x/omapl138" --define=omapl138 --display_error_number --diag_warning=225 --diag_wrap=off --preproc_with_compile --preproc_dependency="main.pp" "../main.c"
'Finished building: ../main.c'
' '
'Building target: led3.out'
'Invoking: C6000 Linker'
"C:/ti/ccsv5/tools/compiler/c6000_7.4.4/bin/cl6x" -mv6740 --abi=eabi -g --define=omapl138 --display_error_number --diag_warning=225 --diag_wrap=off -z --stack_size=0x800 -m"led3.map" --heap_size=0x800 -i"C:/ti/ccsv5/tools/compiler/c6000_7.4.4/lib" -i"C:/ti/ccsv5/tools/compiler/c6000_7.4.4/include" --reread_libs --define=DSP_CORE=1 --warn_sections --display_error_number --diag_wrap=off --xml_link_info="led3_linkInfo.xml" --rom_model -o "led3.out" "./main.obj" "../OMAPL138.cmd" "../library/drivers.lib" -l"libc.a"
<Linking>

undefined first referenced
symbol in file
--------- ----------------
GPIOBank6Pin12PinMuxSetup ./main.obj

error #10234-D: unresolved symbols remain

error #10010: errors encountered during linking; "led3.out" not built
>> Compilation failure
gmake: *** [led3.out] Error 1
gmake: Target `all' not remade because of errors.

**** Build Finished ****

这是为什么啊？