I can give some advice. I passed the training and then worked in this industry for nearly a year. According to your question, different companies have different admission rules, and there is no formula. At that time, before looking for my first job, I had the same trouble from you. Let me talk about my ideas, hoping to help you.

If you interview a junior driver engineer, you only need to be familiar with some important drivers, such as I2C and SPI, and do your homework according to the needs of the company's supply specialty. This stage is the driving force of learning more professionally after entering the job.

If you are a senior engineer and have many years of experience, you naturally know a lot about most drivers, such as USB, network cards, storage devices and so on.

For the driver framework, you must know and be very familiar with the framework, so that you can fill in the corresponding drivers to realize their functions. This aspect will be more important when interviewing for a job, but I think it is easy to master as long as you study the Driver's Code carefully. The key is confidence and perseverance.

"And to what extent do you need to configure the compilation driver after writing?" That's a good question Enterprises and companies are concerned about the product market. As for the degree, you must realize the basic functions well. If you have enough time, try to optimize your code so that the driver takes up less resources, saves more electricity and transmits better data.

The above is my personal opinion, I wish you success!