The ups and downs of life in the Siheyuan

Li Yuan, who was appointed as the executive deputy team leader, thought he would be very busy, but he was not.

The project was launched for a week, but Li Yuan did not receive a single call.

If it's better, Li Yuan can study his flight control system with peace of mind.

A single "KT6501" computer can no longer meet the application of UAV flight control systems.

For the flight control core module, he had to choose the Pangu series PG32V3.5 high-performance CPU.

In order to achieve modular design, each module must have its own unique microcontroller, connected to the flight control core module through a fieldbus.

In order to reduce power consumption, reduce volume, and improve reliability, he needs to design a universal microcontroller for each terminal module.

It can integrate program FLASH, data RAM and peripheral interfaces into one chip, powered by a 3.3V single power supply.

Such integrated chips are often called microcontrollers in later generations.

Meaning a single chip performs all computer functions.

Although it is a brand new design, it is all ready-made technology, and it is only a matter of time to design a dedicated microcontroller.

Now Li Yuan's life is becoming more and more regular, and he practices Qigong with his children in the courtyard in the morning.

After the children went to school, he came to the study room and started designing the microcontroller.

In fact, more often than not, it was him who raised the need, and the design work has been handed over to "Nuwa No. 1".

Half a month later, with the help of Representative Tong, a sunroom was built in the front yard.

The total area is less than 30 square meters, and some wooden shelves have been built on the left and right sides to grow some flowers and plants.

Uncle Song looked at the sunroom. Instead of planting flowers and plants, he planted vegetables and fruits without hesitation.

For example, spinach, leeks, cabbage, tomatoes, cucumbers, cantaloupe, etc.

As long as Uncle Song likes it, Li Yuan and his wife will let it go.

Now Uncle Song stays inside during the day, opens the surrounding windows, and has a floor-standing fan designed by Li Yuan, so he doesn't feel stuffy.

A purple clay pot, a deck chair, half a plate of broad beans, and a pot of old wine are Uncle Song's most comfortable life at present.

As the fruits and vegetables grow and grow, after school every day, this place has also become a paradise for children.

Surrounded by children, the smile on Uncle Song's face was much more than before.

When the first cucumber sat on the vine, the Wukong series microcontroller "WK6901" after multiple compression designs completed the design.

Next, Li Yuan started carving the mask.

While engraving, Li Yuan thought of laser technology and murmured in his mind that he didn't know how domestic laser technology was developing now.

If there is a precision laser engraving machine, mask engraving will be promoted on a large scale.

Thinking of this, he thought of EDA chip design software.

If you want to develop a universal EDA chip design software, it is impossible without a desktop operating system.

So I started the matryoshka mode.

Similarly, later generations are used to desktop operating systems, and now they use the command line input method, and they always have the urge to smash the keyboard.

Therefore, when he designed Nuwa 1, he started the design of desktop operating system.

With the experience of Hongmeng system and the knowledge of later generations, building a desktop operating system requires relatively fewer detours.

When considering the operating system architecture, Li Yuan designed the system into two parts: the kernel and the user.

Taking into account future copyright issues, the new system did not use the name "Hongmeng" but was named the "Galaxy" desktop operating system.

I remember that he struggled for a long time to choose a name. In the end, the name was suggested by Li Le.

After deciding on the name, Li Yuan began to design the operating system.

After writing the framework, set the rules and let "Nuwa No. 1" write the module code and conduct testing.

For example, when designing a floating button, Li Yuan gives a description, and "Nuwa" designs and implements the code.

Li Yuan continued to refine the description and add parameters based on the effect.

When satisfactory results are achieved, "Nuwa" is asked to optimize this code to ensure a certain balance between efficiency and effect.

In the beginning, it was a little slow, but when "Nu Wa" accumulated enough materials, the work became faster.

Li Yuan's participation has also dropped significantly, and he has more time to do other work.

When the module integration and testing are completed, the system integration phase is entered.

At this stage, the biggest problem was encountered.

Since the internal modules of the kernel are coupled to each other, although the scheduling efficiency is improved, it is very easy to cause the system to crash.

No matter how the kernel is optimized, this problem of frequent crashes cannot be effectively solved.

Unfortunately, half a year later, I triggered the sign-in system and got a detailed explanation of operating system skills.

In addition to explaining the principles of operating systems, the skills also come with some typical operating systems.

The content includes common systems such as linux, indosNT, and real-time RTOS.

By searching for knowledge and comparing various systems, he found the real reason for the collapse of the "Galaxy" system.

The core of the first version of "Galaxy" is the large core described in the "Detailed Explanation".

It integrates the six modules of process management, storage management, device management, clock management, interrupt processing and primitives.

Advantages: high performance, various functions within the kernel can directly call each other

Disadvantages: The kernel is huge, the functions are complex, and it is difficult to maintain. An error in a certain functional module in the large kernel may cause the entire system to crash.

Linux and early versions of Windows systems are big kernels.

WindowsNT and later versions are all microkernel systems.

The microkernel puts the core functions such as interrupts, primitives, and process communication into the kernel.

Process management, file management, device management and other functions run in user mode in the form of user processes.

Advantages: The kernel is small, has few functions, is easy to maintain, and has high kernel reliability. An error in a functional module outside the kernel will not cause the entire system to crash.

Disadvantages: low performance, requiring frequent switching of user mode/kernel mode.

Functional modules in user mode cannot directly call each other and can only communicate indirectly through the kernel's "message passing".

Understanding the reason, Li Yuan directly gave up the large kernel system and adopted a microkernel whose stability has been extensively verified.

Compared with the large kernel, the microkernel is less efficient, but its stability and scalability are the mainstream directions of future operating systems.

As hardware performance improves, these differences in efficiency will be ignored.

Three years ago, Li Yuan completed the first version of the "Galaxy 66" design.

Through the kernel test of the "Nuwa" robot, the system is very robust and system crashes are rarely seen.

Based on Cangjie 1.0, Li Yuan spent three months and with the help of "Nuwa" developed the desktop word processing tool "Bisheng", abbreviated as "BSV1.0".

Supports graphics, text and table operations, and fully replicates commonly used functions in office.

Next, it took another 2 years to complete the writing of EDA chip design software.

The full name of EDA is Electronic design automation, which translates to electronic design automation.

Since the operating system and document editing software both have Chinese names, the Chinese name of EDA is "Luban".

Since then, Li Yuan now owns software with independent intellectual property rights:

Desktop operating system: Galaxy;

Document processing software: Bi Sheng;

EDA design tool: Luban.