Modularize the Embedded IPv6 protocol stack (1)

There are no strangers to mobile phones. Among them, its chip is not a real computer chip, but it can be understood as a computer chip cutting version. This is a simple understanding of embedded ideas. So the technology that joins the IPv6 protocol stack can effectively combine the two. This is the topic we will discuss over the past few days.

Design Concept of Embedded IPv6 protocol stack

The IPv6 Micro-protocol stack of the embedded system directly faces the hardware and does not have a multi-task operating system platform. The program structure in the MCU is generally a combination of sequential execution and hardware disconnection, unlike the multi-thread concurrent execution in advanced operating systems. Because the various resources of the single-chip microcomputer system are limited, such as the CPU processing speed, character length, RAM, ROM memory capacity, and number of interfaces, there is a big gap with general-purpose computers, therefore, how to make the Protocol Stack fine, reliable communication, and relatively complete functions, and give full play to the characteristics of single-chip microcomputer has become a key issue in the design of IPv6 Micro-protocol stack. The idea of "miniaturization" is mainly embodied in the core of the design scheme, which should focus on the protocol stack with a small size but no impact on the operation. Therefore, we need to conduct in-depth research on protocol stack cropping, remove unnecessary components, traditional complex Scheduling Mechanisms, and additional extension functions, and even remove operating systems.

Based on the above factors, the design requirements for Embedded IPv6 micro-protocol stack applicable to wireless sensor networks are put forward.

① The Protocol Stack runs on the single-chip microcomputer system and has strong compatibility. It can run correctly over Ethernet and transmit data packets using the wireless data transmission function of 802.15.4 MAC.

② Implement the most basic functions of the IPv6 basic protocol stack core protocol, including IPv6 basic description protocol, ND (Neighbor Discovery) protocol, ICMPv6 (Internet control packet) the automatic configuration protocol of the protocol and IPv6 address.

IPv6 basic Description Protocol: basic functions such as sending, receiving, and processing IPv6 data packets.

ND (Neighbor Discovery) Protocol: The Address Resolution function of neighbor discovery to implement neighbor requests and neighbor notifications.

ICMPv6 (Internet control packet) Protocol: mainly implements Message Processing for control packets, as well as response requests and responses to the Network diagnosis function.

Automatic IPv6 Address Configuration Protocol: According to the IPv6 address format requirements, the local address of the IPv6 link is configured and the multicast address of the requesting node is configured.

③ Improve the correctness of ICMPv6, TCP and other protocols by calculating and processing the checksum fields.

④ Implement simple application layer protocols (such as TELNET and SNMP protocols), and use remote terminals to log on to the microcontroller system running the Embedded IPv6 protocol stack, and perform simple control and management operations.