pbuf alloc not able to allocate memory

[User39504831]

Hi

Am using TC37x lite kit and implementing UDP using lwip stack. 

Here's how am using `pbuf`

`

char buffer[100] = "hello world";

struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, sizeof(buffer), PBUF_RAM);

`

after this am getting `p` as NULL.

Am using default linker script ( generated from ADS), psram_x = 64k and heap = 4k

This udp implementation is the only one currently running on my board. So am confused as to why memory is not getting allocated

Need some help

Thanks

[Di_W · Accepted solution]

Please trace into pbuf_alloc, and then should know the reason. 

By default, lwIP utilizes a static heap for mem_malloc(), but you have the option to use the C standard library malloc () and free() instead. Additionally, lwIP allows custom memory pools to emulate dynamic allocation.

You can check which of the three memory allocation methods mentioned above is being used by your system and ensure that the memory is properly initialized.

Reference 1: Buffer and Memory Management

Chapters: 6.1 Packet Buffers (Pbufs) and 6.2 Memory Management

Link: https://www.artila.com/download/RIO/RIO-2010PG/lwip.pdf

Reference 2: lwIP Application Developers Manual

Chapter: lwipopts.h

Section: Memory Management (RAM Usage)

Link: https://lwip.fandom.com/wiki/Lwipopts.h