[lwip-users] IP Header does not fit in the first pbuf!!!

[A. Assal]

Hi,

I'm trying to use LwIP in my research. I am using it with ucOS-II running under motorola HC9S12 microcontroller.

I haven't succeeded yet to ping the board. every packet sent from win2K through the SLIP connection to the board is dropped.

I got the message "IP Header (len 20) does not fit in the first pbuf (len 1), IP packet dropped"

Is there anything I am missing? has anyone had the same problem?

Since I have just 12K of RAM, my opt.h is set as follow

 

#ifndef MEM_ALIGNMENT
#define MEM_ALIGNMENT                   2
#endif

 

/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high. */
#ifndef MEM_SIZE
#define MEM_SIZE                      1024*1 ///1600
#endif

 

/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
   sends a lot of data out of ROM (or other static memory), this
   should be set high. */
#ifndef MEMP_NUM_PBUF
#define MEMP_NUM_PBUF                   16
#endif

 

/* Number of raw connection PCBs */
#ifndef MEMP_NUM_RAW_PCB
#define MEMP_NUM_RAW_PCB                2
#endif

 

/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
   per active UDP "connection". */
#ifndef MEMP_NUM_UDP_PCB
#define MEMP_NUM_UDP_PCB                2 //4
#endif
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB
#define MEMP_NUM_TCP_PCB                0//10
#endif
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB_LISTEN
#define MEMP_NUM_TCP_PCB_LISTEN         0//8
#endif
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
   segments. */
#ifndef MEMP_NUM_TCP_SEG
#define MEMP_NUM_TCP_SEG                0//8
#endif
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
   timeouts. */
#ifndef MEMP_NUM_SYS_TIMEOUT
#define MEMP_NUM_SYS_TIMEOUT            3
#endif

 

/* The following four are used only with the sequential API and can be
   set to 0 if the application only will use the raw API. */
/* MEMP_NUM_NETBUF: the number of struct netbufs. */
#ifndef MEMP_NUM_NETBUF
#define MEMP_NUM_NETBUF                 0
#endif
/* MEMP_NUM_NETCONN: the number of struct netconns. */
#ifndef MEMP_NUM_NETCONN
#define MEMP_NUM_NETCONN                0
#endif
/* MEMP_NUM_APIMSG: the number of struct api_msg, used for
   communication between the TCP/IP stack and the sequential
   programs. */
#ifndef MEMP_NUM_API_MSG
#define MEMP_NUM_API_MSG                0
#endif
/* MEMP_NUM_TCPIPMSG: the number of struct tcpip_msg, which is used
   for sequential API communication and incoming packets. Used in
   src/api/tcpip.c. */
#ifndef MEMP_NUM_TCPIP_MSG
#define MEMP_NUM_TCPIP_MSG              0
#endif

 

/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */

 

#ifndef PBUF_POOL_SIZE
#define PBUF_POOL_SIZE                  4 //12
#endif

 

/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */

 

#ifndef PBUF_POOL_BUFSIZE
#define PBUF_POOL_BUFSIZE               128
#endif

 

/* PBUF_LINK_HLEN: the number of bytes that should be allocated for a
   link level header. */

 

#ifndef PBUF_LINK_HLEN
#define PBUF_LINK_HLEN                  16
#endif

Any help will be appreciated

Thanks

Dan