MPU Is A Hardware Protection Mechanism

MPU is a hardware protection mechanism used to protect memory security in embedded systems. It is a special module in embedded processors, usually integrated with the CPU on the same chip. The main function of MPU is to limit the access permissions of programs to specific memory areas, thereby preventing illegal access of programs to critical data in the system, and improving the security and stability of the system.

The main working principle of MPU is to partition the memory address space, divide the system's memory into multiple regions, and assign corresponding access permissions to each region. These access permissions can be read, write, execute, or prohibit. When a program attempts to access a memory area, MPU checks whether the program is authorized to access that area and restricts it based on permissions. If the program is not authorized to access the memory area, MPU will generate an exception and terminate program execution, thereby protecting memory security.

MPU has the following functions and applications in protecting memory security:

1. Preventing buffer overflow attacks

Buffer overflow attack is a common hacker attack method that can overwrite other data in the program's memory by inputting a large amount of data into the program, thereby achieving illegal access and control of the system. MPU can prevent buffer overflow attacks by restricting program access to memory.

2. Preventing the spread of malicious software

Malware typically utilizes system vulnerabilities to spread and control the system. MPU can prevent the spread of malicious software and control the system by restricting program access permissions.

3. Preventing stack overflow

Stack overflow is a common programming error that can cause system crashes or data corruption. MPU can prevent stack overflow and protect system stability by restricting program access permissions.

4. Protecting System Critical Data

Some key data in the system, such as passwords, encryption keys, etc., require special protection. MPU can protect system security by restricting program access to critical data.

5. Prevent unauthorized access to peripherals

Peripherals in a system typically require specific access permissions to prevent unauthorized access and control. MPU can assign corresponding access permissions to each peripheral and restrict program access to external devices to protect their security.

In summary, MPU is a very important protection mechanism that can protect memory security and improve system security and stability in embedded systems. By properly configuring and using MPUs, various hacker attacks and programming errors can be effectively prevented, and the data and functions of the system can be protected.