Embedded C 面试题与答案

问题 21. What is the purpose of the 'inline' keyword in C?

The 'inline' keyword suggests to the compiler that a function should be expanded in-place at the call site, potentially improving performance.

Example:

inline int add(int a, int b) { return a + b; }

问题 22. Explain the role of a bootloader in embedded systems.

A bootloader is a program that loads the main application into the microcontroller's memory, typically from external storage like flash or EEPROM.

问题 23. What is the purpose of the 'const' pointer in C?

A 'const' pointer points to a constant value, meaning the value it points to cannot be modified through the pointer.

Example:

const int *ptr;

问题 24. Explain the concept of polling versus interrupt-driven I/O.

Polling involves repeatedly checking the status of a device, while interrupt-driven I/O relies on hardware interrupts to notify the processor when the device needs attention.

问题 25. What is the purpose of the 'enum' keyword in C?

The 'enum' keyword is used to define named integer constants, providing a more readable alternative to using raw integer values.

Example:

enum Days { Monday, Tuesday, Wednesday, Thursday, Friday };