CCS/EK-TM4C1294XL: Problem getting a pbuf?

Ja Hv

Part Number: EK-TM4C1294XL

Tool/software: Code Composer Studio

I have the following code

#include <stdint.h>
#include <stdbool.h>
#include <string.h>

#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/flash.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "driverlib/timer.h"
#include "drivers/pinout.h"

#include "lwip/udp.h"
#include "utils/locator.h"
#include "utils/lwiplib.h"
#include "utils/uartstdio.h"
#include "utils/ustdlib.h" 


void main() {
  struct pbuf *pdat;

  do {
    pdat = pbuf_alloc( PBUF_TRANSPORT, 100, PBUF_RAM);
  } while (pdat==NULL);

  .. further code ..
}

The program never leaves the loop. I.e. I do not get a pbuf allocated!

What am I missing?

over 5 years ago

0 Chester Gillon over 5 years ago

Guru 92251 points

What is in the Memory options section of the lwipopts.h file used by the project?

Looking at the ent_lwip project from TivaWare 2.2.0.295 shows the following in lwipopts.h which allocates 64K of memory for lwip, in the ram_heap static array:

//*****************************************************************************
//
// ---------- Memory options ----------
//
//*****************************************************************************
//#define MEM_LIBC_MALLOC                 0
#define MEM_ALIGNMENT                     4
#define MEM_SIZE                          (64 * 1024)
//#define MEMP_OVERFLOW_CHECK             0
//#define MEMP_SANITY_CHECK               0
//#define MEM_USE_POOLS                   0
//#define MEMP_USE_CUSTOM_POOLS           0

0 Charles Tsai over 5 years ago in reply to Chester Gillon

TI__Guru**** 191906 points

Hi Chester,

Thanks. Perhaps the poster can also check the stack size.

0 Ja Hv over 5 years ago in reply to Chester Gillon

Intellectual 630 points

In lwipopts.h I have the same lines as Chester Gillon shows. (64k)

I have version 2.1.4.178, however. And 2.2.0.295. Not quite sure, which one is in use.

As far as I can see, that file has NOT been included! (unless by some of the others)

As to the question from Charles Tsai:

Stack size (Arm Linker - Basic) says 512.

Same place Heap is set to 0!?

A try setting the heap to 2.048 or 100.000, or raising the stack to 5.120 does not help.

(European 1.000 indicator) :-)

0 Chester Gillon over 5 years ago

Guru 92251 points

Ja Hv said:
The program never leaves the loop. I.e. I do not get a pbuf allocated!

The code fragment shows pbuf_alloc being called before lwIPInit has been used to initialise the lwIP library.

In the code below two calls to pbuf_alloc were added to the main of the ent_lwip example, where pbuf_alloc was called before and after the lwIP library had been initialised:

    struct pbuf *volatile pdat;
    pdat = pbuf_alloc( PBUF_TRANSPORT, 100, PBUF_RAM);

    //
    // Initialize the lwIP library, using DHCP.
    //
    lwIPInit(g_ui32SysClock, pui8MACArray, 0, 0, 0, IPADDR_USE_DHCP);

    pdat = pbuf_alloc( PBUF_TRANSPORT, 100, PBUF_RAM);

The pbuf_alloc call prior to lwIPInit returned NULL. Whereas the pbuf_alloc call after lwIPInit returned a non-NULL pbuf (i.e. the allocation was successful).

0 Ja Hv over 5 years ago in reply to Chester Gillon

Intellectual 630 points

Yes!

I had that lwIPInit statement in my setup, but setup was commented out. I am using static IP, but otherwise...

Now I get a buffer.

On to the next hurdle.

Arm-based microcontrollers

Arm-based microcontrollers forum

CCS/EK-TM4C1294XL: Problem getting a pbuf?