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AR# 19591

6.2 EDK SP2 - Problems occur when I use the LwIP netconn_* function


Keywords: XPS, Service Pack

Urgency: Standard

General Description:
When I use the netconn functions in the C code, compiling errors occur in EDK 6.2. The lwip.pdf document includes a code example that uses the netconn_* functions in the "Network Connection Functions" section. This document is located at:

The C code is similar to the following:

#include "lwip/api.h"

int main()
struct netconn *conn, *newconn;

/* create a connection structure */
conn = netconn_new(NETCONN_TCP);

/* bind the connection to port 2000 on any local IP address */
netconn_bind(conn, NULL, 2000);

/* tell the connection to listen for incoming connection requests */

/* block until we get an incoming connection */
newconn = netconn_accept(conn);

/* do something with the connection */

/* deallocate both connections */



The above code produces the following errors during compilation (for mb-gcc and powerpc-eabi-gcc):

/xygdrive/c/TEMP/ccHg24DI.o: In function `main':
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x10): undefined reference to `netconn_new'
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x28): undefined reference to `netconn_bind'
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x34): undefined reference to `netconn_listen'
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x40): undefined reference to `netconn_accept'
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x58): undefined reference to `netconn_delete'
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x64): undefined reference to `netconn_delete'
/xygdrive/c/TEMP/ccHg24DI.o: In function `process_conn':
/xygdrive/c/TEMP/ccHg24DI.o(.text+0x84): undefined reference to `netconn_receive'
./microblaze_0/lib//libxil.a(microblaze_interrupts_g.o)(.data+0x0):/xygdrive/h/CASES/Pfeffer_manuel_etherent_problem/mb_lwip_echo_550/mb_lwip_echo_550/microblaze_0/libsrc/standalone_v1_00_a/src/microblaze_interrupts_g.c: undefined reference to `mytimer_int_handler' Done.


The mode that is used to program is the sockets interface-based mode; this mode is not yet supported. This mode will be supported in the EDK 6.3 release.

In 6.2 SP2, you must use the raw interface that is described in the lwIP section in the "EDK OS and Libraries Reference Guide" at:

AR# 19591
Date 04/28/2006
Status Archive
Type General Article