Getting started with LwIP

Folder structure

The original LwIP folder structure is modified to add files needed by the STM32CubeMX tool for configuration and code generation.

LwIP folder structure

  • src: LwIP stack source files.

    • api: Netconn and Socket LwIP API files (require RTOS).

    • apps: This folder holds a set of network applicative protocols.

    • core: LwIP core files: fundamental functions, data structures and protocols (IP, UDP, TCP, etc.).

    • include: header files for the other folders.

    • netif: generic management of network interfaces.

  • .config: CubeMX configuration UI and templates files

  • app_samples: application example (how to configure the interfaces, start LwIP, …)

  • interfaces: common files for implementation of Low-level interface between LwIP and hardware interfaces

Configuration options & files

  • configuration file: lwipopts.h

lwipopts.h flag name

Description

NO_SYS

Disable (NO_SYS=1) or enable (NO_SYS=0) RTOS support. Netconn and Socket APIs require RTOS support (NO_SYS=0).

MEM_SIZE

LwIP heap size. Used for transmit buffers allocation.

PBUF_POOL_SIZE

Number of buffers in the “PBUF” pool. Used for reception buffers.

LWIP_IPV4

Enable Internet protocol version 4 (default)

LWIP_TCP

Enable TCP protocol

LWIP_UDP

Enable UDP protocol

LWIP_ARP

Address Resolution Protocol for IP and Ethernet addresses

LWIP_SOCKET

Enable BSD-style Socket API

TCP_MSS

TCP maximum segment size

TCP_WND

TCP window (at least 2 * TCP_MSS)

MEMP_NUM_TCP_PCB

The number of simultaneously active TCP connections

LwIP APIs Description table

LwIP API Functions | Link

main page

LwIP online documentation

Warning

This page is currently under development and may be incomplete or subject to change.