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New FreeRTOS+TCP driver for STMF32F4

Posted by heinbali01 on March 20, 2017

Please find attached a new NetworkInterface.c for STM32F4. It has implemented the zero-copy feature in both directions, and therefore it is more efficient and faster than its earlier version.

I would like to invite anyone interested to try it out. Be aware that it may not be as stable yet as the existing driver. I tested it with UDP/TCP/ICMP/etc, and also with iperf.

The following settings are recommended for this driver:

~~~ /* Add to your 'FreeRTOSIPConfig.h'. */ #define ipconfigZEROCOPYRXDRIVER 1 #define ipconfigZEROCOPYTXDRIVER 1 #define ipconfigETHERNETDRIVERFILTERS_PACKETS 1

/* Add/change to your stm32f4xx_hal_conf.h : */

#include "FreeRTOS.h"
#include "task.h"
#include "FreeRTOSIPConfig.h"

#define ETH_RX_BUF_SIZE            ( ipconfigNETWORK_MTU + 36 )/* buffer size for receive */
#define ETH_TX_BUF_SIZE            ( ipconfigNETWORK_MTU + 36 )/* buffer size for transmit */


By default, ETH_RX_BUF_SIZE / ETH_TX_BUF_SIZE are defined as ETH_MAX_PACKET_SIZE, which is hard-coded as 1536.

With a limited amount of RAM, it may be very profitable to reduce the value of ipconfigNETWORK_MTU to e.g. (1024+40). So let tha value of ETH_RX_BUF_SIZE / ETH_TX_BUF_SIZE depend on ipconfigNETWORK_MTU.

The new driver will also filter incoming packets. That can be important in networks with many UDP broadcasts. These packets should be filtered-out as soon as possible in order not to occupy resources.

The following CUBE/HAL functions won't be called any more:


For two reasons: they're not compatible with zero-copy, and/or the in-line implementation is faster.

The interface will now work for two types of PHY's: DP83848I ( found on STM324xG-EVAL ), and also LAN8720 ( found on STM32F4-DISCOVERY ).

New FreeRTOS+TCP driver for STMF32F4

Posted by heinbali01 on March 20, 2017

I pressed on Post too soon, hadn't attached the driver yet. Here it is


NetworkInterface.c (47127 bytes)

New FreeRTOS+TCP driver for STMF32F4

Posted by heinbali01 on March 21, 2017

As xNetworkInterfaceInitialise() had become quite large and therefore less readable, I've split up some code into separate functions:

~~~ /* Initialise TX-descriptors. */ prvDMATxDescListInit();

/* Initialise RX-descriptors. */


This time I also I included the latest iperf3 module. I tested on a STM3240G-EVAL, using the following defines for iperf:

~~~ /* Some defines for iperf, optimised for speed. / / Put these in your 'FreeRTOSIPConfig.h' */ #define ipconfigIPERFDOESECHO_UDP 0

#define ipconfigIPERF_VERSION                   3
#define ipconfigIPERF_STACK_SIZE_IPERF_TASK     680
#define ipconfigIPERF_TX_BUFSIZE                ( 8 * ipconfigTCP_MSS )
#define ipconfigIPERF_TX_WINSIZE                ( 6 )
#define ipconfigIPERF_RX_BUFSIZE                ( 8 * ipconfigTCP_MSS )
#define ipconfigIPERF_RX_WINSIZE                ( 6 )

/* The iperf module declares a character buffer to store its send data. */
#define ipconfigIPERF_RECV_BUFFER_SIZE          ( 2 * ipconfigTCP_MSS )


The above parameters are optimised for speed.

The iperf driver can be started by calling vIPerfInstall() once after the network is up ( vApplicationIPNetworkEventHook() is called with eNetworkUp ).

Here is an example optimised for memory usage:

~~~ /* Defines for iperf, optimised for memory usage. */ #define ipconfigIPERFTXBUFSIZE ( 3 * ipconfigTCPMSS ) #define ipconfigIPERFTXWINSIZE ( 2 ) #define ipconfigIPERFRXBUFSIZE ( 3 * ipconfigTCPMSS ) #define ipconfigIPERFRXWINSIZE ( 2 ) ~~~

Today I re-tested the memcpy() mode: it still functions. Using zero-copy is especially profitable when the device is sending data.

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