LwIP is a lightweight TCP/IP protocol stack, which has been widely used in embedded systems. Here are some detailed explanations of the lwIP protocol:
Protocol architecture: lwIP protocol stack is mainly composed of four layers, namely application layer, transport layer, network layer and network interface layer.
TCP/IP protocol support: lwIP protocol stack supports commonly used TCP/IP protocols, such as TCP, UDP, IP, ICMP, etc.
Memory management: lwIP protocol stack uses a data structure called pbuf to manage memory. Pbuf is a packet buffer that can contain one or more packets.
Interface management: lwIP protocol stack supports various network interface types, such as Ethernet, PPP, SLIP, etc.
Support multiple operating systems: lwIP protocol stack can run on multiple operating systems, such as Linux, FreeRTOS, uC/OS, etc.
Support protocol extension: lwIP protocol stack supports protocol extension, and users can add new protocols as needed.
In a word, lwIP protocol stack is a general lightweight TCP/IP protocol stack, especially suitable for network applications in embedded systems.
How to modify the shell stack?
Add ulimit-sunlimited to save at the end of /etc/profile, and source/etc/profile will make the modified file effective. Linux can view the default stack space size of the modified thread: ulimit-s 1, and view the default stack space size of linux through the command ulimit-s, which is 10240 by default, that is, 10M2. You can temporarily change the size of the stack space by setting the size value by the command ulimit-s: ulimit-s 102400, that is, changing it to 100M3, and you can add ulimit-s 10240 in/etc/rc.local.
How big is the default stack for linux threads?
The thread stack size of linux can be viewed by ulimit-s, and the default size of the kernel thread stack of ubuntu2.6 is 8m.