I am now developing a USB application based on C6747 DSP and examples within biosusb_01_00_00 package are HID and MSC. So, I changed it to Serial class. But, when I compile the project, the following error occurs:

-----------------------  usb_dev_msc_sample.pjt - Debug  -----------------------
[devinit.c] "C:\CCStudio_v3.3\C6000 Code Generation Tools 6.1.9\bin\cl6x" -g -fr"C:/CCStudio_v3.3/biosusb_01_00_00/packages/ti/biosusb/examples/usbdevmsc1/build/Debug" -i"./" -i"../../../../" -i"../../../" -i"../../" -i"../../../device" -i"C:/CCStudio_v3.3/pspdrivers_01_20_00/packages" -i"C:/CCStudio_v3.3/pspdrivers_01_20_00/packages/ti/pspiom/cslr" -i"C:/CCStudio_v3.3/rtfs_1_00_01/packages/ti/rtfs/config" -i"C:/CCStudio_v3.3/rtfs_1_00_01/packages/ti/rtfs" -i"C:/CCStudio_v3.3/edma3_lld_01_06_00_01/packages" -d"CONFIG_DEVICE" -d"CONFIG_INCLUDE_FD" -mv6740 -@"../build/Debug.lkf" "devinit.c"

[Linking...] "C:\CCStudio_v3.3\C6000 Code Generation Tools 6.1.9\bin\cl6x" -@"Debug.lkf"
<Linking>

 undefined    first referenced                                                                                          
  symbol          in file                                                                                               
 ---------    ----------------                                                                                          
 _serial_init C:\\CCStudio_v3.3\\biosusb_01_00_00\\packages\\ti\\biosusb\\examples\\usbdevmsc1\\build\\Debug\\devinit.obj

error: unresolved symbols remain
error: errors encountered during linking; "./Debug/devmsc_sample.out" not
   built

>> Compilation failure

Build Complete,
  1 Errors, 0 Warnings, 0 Remarks.

I am using CCS3.3 SR11, bios_5_33_06, pspdrivers_01_20_00, cgt 6.1.9, biosusb_01_00_00. The above error shows that serial_init is not defined while mass_storage_init(MSC example uses it) does not cause that error. Why? I change the code as follows:

/** \file   devinit.c

/* function driver initialization function */
extern result_t serial_init(void *ctx);

#ifdef CONFIG_JSLAVE
/* add your function driver */
static fd_instance_t fd_instances[] = {
    { DEVICE_TYPE_VENDOR, CONFIG_FD_SERIAL, serial_init },
    { DEVICE_TYPE_NONE, 0, NULL }
};

/** \file config_device.h

#define CONFIG_INCLUDE_FD  1
/* function driver definitions */
#ifdef CONFIG_INCLUDE_FD
//#define CONFIG_FD_MASS    1
/* # HID Lib and Keyborad FD */
//#define CONFIG_FD_HID   1
//#define CONFIG_FD_HID_LIB  1
//#define CONFIG_FD_HID_KEYBOARD 1
#define CONFIG_FD_SERIAL        1
//#define CONFIG_FD_CDC_ACM       1
/*# Structure for Keyboard demo*/
//#define FD_HID_KBD_DEMO   1
#endif

 My project file is:3113.usbdevmsc.rar