Problem with linking : Error: L6218E: Undefined symbols

Looks like you're still at least one file short. You need to find which file has these USART functions and add that to your project. If you already have the file make sure you have the right defines passed into the compiler.

Looks like you're still at least one file short. You need to find which file has these USART functions and add that to your project. If you already have the file make sure you have the right defines passed into the compiler.

USART functions files(bsp_uart.c) have added to project, main.c and bsp.c have included "bsp_uart.h".
The problem are not simple as they look like.

some codes in main.c:

#include  "includes.h"
#include  "bsp.h"

some codes in bsp.c:

#include  "includes.h"
#include  "bsp.h"

some codes in bsp.h:

#ifndef _BSP_H_
#define _BSP_H_

typedef  float     fp32;
typedef  double    fp64;

#include <stm32f4xx.h>

#include "bsp_gpio.h"
#include "bsp_fsmc_sram.h"
#include "bsp_led.h"
#include "bsp_i2c_gpio.h"
#include "bsp_eeprom_24xx.h"
#include "bsp_spi_flash.h"
#include "bsp_dac.h"
#include "COMM_Q.h"
#include "bsp_uart.h"
#include "bsp_dwt.h"
#include "dRAM_proto.h"
#include "ChannelData.h"

some codes in bsp_uart.h:

/***************************** USART1 Declaration *****************************/
           u8  UART1_Init(void);
         void  UART1_GPIO_Config(void);
         void  UART1_Config(void);
         void  UART1_DMA_Config(void);
         void  UART1_NVIC_Config(void);
         void  DMA2_Stream7_IRQHandler(void);
         void  DMA2_Stream5_IRQHandler(void);
         void  UART1_RxDMA_ReceiveLeftStr(void);
         void  UART1_SendData(COMM_Q_char *dp);
COMM_Q_Status  UART1_GetAllString(COMM_Q_char *dp);
COMM_Q_Status  UART1_GetDefineString(COMM_Q_char *dp, COMM_Q_char ch);
         void  UART1_RemoveAllSendData(void);
/*************************** End USART1 Declaration ***************************/

/***************************** USART3 Declaration *****************************/
           u8  UART3_Init(void);
         void  UART3_GPIO_Config(void);
         void  UART3_Config(void);
         void  UART3_DMA_Config(void);
         void  UART3_NVIC_Config(void);
         void  DMA1_Stream3_IRQHandler(void);
         void  DMA1_Stream1_IRQHandler(void);
         void  UART3_RxDMA_ReceiveLeftStr(void);
         void  UART3_SendData(COMM_Q_char *dp);
COMM_Q_Status  UART3_GetAllString(COMM_Q_char *dp);
COMM_Q_Status  UART3_GetDefineString(COMM_Q_char *dp, COMM_Q_char ch);
         void  UART3_RemoveAllSendData(void);
/*************************** End USART3 Declaration ***************************/

OK, but where is the code in bsp_uart.c?

Is that dependent on a define? For whatever reason the body of the functions are not getting compiled. This should be apparent with careful evaluation of the source.

Because have writed description, so there's no post codes.

some codes in bsp_uart.c:

#include "bsp.h"

/***************************** USART1 Definition *****************************/
static   OS_EVENT           *UART1Sem;

static   UART_Data_t         Uart1_Data;
static   COMM_Q_char         UART1_RxTmpBuf[UART1_FIFO_LENGTH + 1];

static   DMA_InitTypeDef     DMA_UART1TxStructure;
static   DMA_InitTypeDef     DMA_UART1RxStructure;
/*************************** End USART1 Definition ***************************/

/***************************** USART3 Definition *****************************/
static   OS_EVENT           *UART3Sem;

static   UART_Data_t         Uart3_Data;
/*************************** End USART3 Definition ***************************/

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// USART1 Function
// USART1 work with DMA mode using DMA2_Stream5 and DMA2_Stream7.
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


/*+++++ association code +++++*/
/******************************************************************************
*                                      UART1_Init()
*
* Description : Initialize the USART1 peripheral.
* Argument(s) : none.
* Return(s)   : TRUE or FALSE.
* Caller(s)   : BSP_Init().
* Note(s)     : none
******************************************************************************/
u8 UART1_Init(void)
{
        COMM_Q_Status tmpSts;

    UART1_GPIO_Config();
    UART1_Config();
    UART1_DMA_Config();
    UART1_NVIC_Config();


    tmpSts = COMM_QCreate(&Uart1_Rx_Q, Uart1_Data.RxBuffer, UART1_RxBufferSize);
    if (tmpSts == COMM_Q_FAILURE) {
        return FALSE;
    }
    tmpSts = COMM_QCreate(&Uart1_Tx_Q, Uart1_Data.TxBuffer, UART1_TxBufferSize);
    if (tmpSts == COMM_Q_FAILURE) {
        return FALSE;
    }

        UART1Sem   = OSSemCreate(1);
        if (UART1Sem == NULL) {
                return FALSE;
        }

        return TRUE;
}


/*+++++ association code +++++*/
/******************************************************************************
*                                      UART3_Init()
*
* Description : Initialize the USART3 peripheral.
* Argument(s) : none.
* Return(s)   : TRUE or FALSE.
* Caller(s)   : BSP_Init().
* Note(s)     : none
******************************************************************************/
u8 UART3_Init(void)
{
        COMM_Q_Status tmpSts;

    UART3_GPIO_Config();
    UART3_Config();
    UART3_DMA_Config();
    UART3_NVIC_Config();


    tmpSts = COMM_QCreate(&Uart3_Rx_Q, Uart3_Data.RxBuffer, UART3_RxBufferSize);
    if (tmpSts == COMM_Q_FAILURE) {
        return FALSE;
    }
    tmpSts = COMM_QCreate(&Uart3_Tx_Q, Uart3_Data.TxBuffer, UART3_TxBufferSize);
    if (tmpSts == COMM_Q_FAILURE) {
        return FALSE;
    }

        UART3Sem   = OSSemCreate(1);
        if (UART3Sem == NULL) {
                return FALSE;
        }

        return TRUE;
}


/*+++++ association code +++++*/
/******************************************************************************
*                                      UART1_RxDMA_ReceiveLeftStr()
*
* Description :
* Argument(s) : none.
* Return(s)   : none.
* Caller(s)   : none.
* Note(s)     : none
******************************************************************************/
void UART1_RxDMA_ReceiveLeftStr(void)
{
        u16 i;

        COMM_QPushStr(&Uart1_Rx_Q, UART1_RxTmpBuf);

        DMA_Cmd(DMA2_Stream5, DISABLE);
        DMA_UART1RxStructure.DMA_MemoryBaseAddr = (u32)UART1_RxTmpBuf;
        DMA_UART1RxStructure.DMA_BufferSize = (u32)UART1_FIFO_LENGTH;
        DMA_Init(DMA2_Stream5, &DMA_UART1RxStructure);
        DMA_Cmd(DMA2_Stream5, ENABLE);

        for (i=0; i<UART1_FIFO_LENGTH+1; i++) {
                UART1_RxTmpBuf[i] = 0;
        }
}

Finded the reason of error.

Click the right mouse button to view file "bsp_uart.c" options, The 'Path' is wrong, correct path and rebuild project, compiling is OK.

Thanks!