Self-control of the seriousness of the gossip about the two CPU
https://zhuanlan.zhihu.com/p/62399200
Self-control of the seriousness of the gossip about the two CPU
Speaking of the book back on the first level of self-control CPU instruction set issue. This time next chat design problems.
The second CPU design articles
In the design level, there are two routes: one is self-designed, one is ism.
CPU design is the meaning of autonomy, starting from the definition of requirements and functional objectives, fully forward design of each unit and module CPU. Put a little vernacular, stitch, brick by brick are my own, inside and out, up and down I have a clear message. This obviously will not bring any design ideas subjective "back door" (unless good people can not control, malicious implants, which are discussed later in talent level). Design aspects also include tools and equipment used, some of the processes require the use of tools or equipment automatically. To protect the CPU design completely clear vain, tools and equipment are also to comply with the conditions of self-control, or we have reason to suspect that these automated process may be mixed with illegal logic. If it continues to go on traceability, production, design tools and equipment of these companies have to do further checks on the part of the entire process, the design and manufacturing process of these tools and equipment to ensure that controlled whether ...... Some may say this is unfounded but safety is no small matter, or caution.
Ism is completely copy the existing design abroad, that is, some experts call "vest" - this popular mountain sketch, vivid image. "Vest" CPU core code or technology are from abroad, and no local experienced technical team to digest understand, there is no "back door" was not sure, at best, only be regarded as domestic brands, may not supply problem , but technical support and capacity for sustainable development on the worrying. This technique route design level apparently unable to achieve self-control.
Since the CPU complex functions, many modules, these two routes are far too extreme, the reality of China-made CPU is often somewhere in between, but the difference is not so critical module has independent design, the other is on the key instead of using independent tools and equipment. Which modules are crucial, which modules are non-critical, the key to which links, which links non-critical, that is a matter of opinion. Usually we think is the key to the processor core, after all, it is responsible for calculating, he did not; storage is the key, after all, he was responsible for the data, it did not work; interconnection is critical, after all, it is responsible for communication, it did not work; IO like the key is, after all ...... this row continues, as if one less, after all, who is nothing to put some useless things take a place yet. So, advocates often say what they can do what is critical.
So now domestic CPU have adopted the basic compromise route, after all, self-control does not mean back to the primitive society. If you really back to the primitive society, even if it is self-control, and how to fight this battle be?
In fact, the history of the country to do CPU should be started in the late 1990s. If you go down to the retrospective about 104 machines earlier, 109,441B, Galaxy 1 and Galaxy 2 have their own central processing unit, instead of a central processor. Why is it called the processor it? Because it is a small-scale integrated circuits and discrete components or structures, not in the modern sense VLSI CPU chip. If this principle had computer courses on eight college nineties, we should have to take this type of instruments used by 74LS components, adder, experimental class experience controllers.
Domestic real talk CPU design of these chips origin or caused by the embargo, especially military equipment in the CPU. At that time not only China, but also pay attention to the US military COTS (Commercial Off-The-Shelf), that is, as far as possible the use of sophisticated COTS products to meet the needs of military equipment, the biggest advantage is saving time and money, but the biggest problem is the short-cycle commercial products , while the long period of military equipment, supply security is a problem. China's military equipment in addition to stock Kaner, but also could face embargo. So the demand was first instituted by the military, specify a number of domestic enterprises and research institutes imitation mainstream CPU on the market at that time, to prepare for contingencies, scientific name is called reverse engineering. Do not underestimate the reverse engineering, it is not a simple copy, but the product wafers cut open, polished layers, photographic, a transistor and a transistor, functional analysis, mapping logic, then the reliability of reinforcement , simulation and verification, and finally to the production process of the target line. This process circuit designers the ability, logical ability and structural capacity is a great challenge and experience, it is said Harbin Military Engineering Institute (now called the Grand National Defense Science and Technology) CPU and DSP is the team to beat from this process, Shenzhen home early-stage companies also specialize in reverse, there is a core vision is reportedly in the process of growing up to do so EDA tool companies reverse-engineered. Technology largest defense had reversed a CPU is Intel x86, pin-compatible level, because of the change process, done reinforcement, performance and reliability is better than commodity x86. Later said the country would also reverse other high-performance x86, are assigned to domestic forward shot dead, said Godson are out, but also reverse ball, Godson is not finished. To be honest, fifteen years later, now single-core CPU performance than several domestic PentiumIII no where to go strong, then it is impossible to see. A friend might say: Nonsense, Godson now PK Core i3, i5 up. Ten years ago, looking through the Godson had to catch the Premier League US news reports, you can deeply impressed by this show, if you have not understand, please refer to the recent Audi pk crayfish opera. Then reverse chips are used in the key equipment, is now with a chip but few dare to use it really, this is not it ironic?
Reverse engineering is the CPU to break the embargo localization of a way to achieve, but it is not a feasible way of development of China-made CPU industry, the military can be used with, it is clearly not up for sale in the commercial sector. So now we talk about domestic CPU is designed to correct me, we are on the industry level to consider. If only the military, imitation and steal system (do not get authorization) are a viable solution, then the point amount, not affect his interests, the US imperialists do not bother you.
Forward-made CPU design began in the beginning of the new century, in August 2001, based on MIPS 32 Godson took three months to change a Godson1 out (nicknamed "dog left"), boot the OS on FPGA, and wrote a male text "our CPU" (who are interested can go and see search network), ignited the enthusiasm of the people of China-made CPU. Almost at the same time, by more than 20 experts identified as "advanced international level" and "Ark One" also turned out, but the "Ark" Strictly speaking or embedded CPU, while the Godson-1 is to aim at a general purpose CPU (although now Godson-1 is positioned as an embedded solution, but was prepared with intel on the subject). At that time, "Ark" is already sampling, the Godson-1 only in the FPGA boot the operating system, until 2002 taped. So, I think have to be considered the first positive Ark, ^ _ ^.
Since then, the state began to gradually importance to the development of China-made CPU, established a number of topics from the 863 plan to support. In addition to the Godson, Ark, there are several domestic chip design heritage of the units have been subject, PKUnity, large Defense Science and Technology, Shanghai high-performance, micro-transit and so on, of course, the computer chip. And Godson similar PKUnity, Shanghai high-performance were improved design is based on AMD's x86 processors and DEC Alpha21264 processor on, and soon came up with the first generation of products, but taking a big defense technology completely different way. Probably because its supercomputing technology roadmap, Defense Science and Technology decided to design large-compatible CPU IA-64's. But we all know that Intel IA-64 and HP was the latest development of the instruction set, the product is Itanium Itanium, called the most cow B server CPU. And other routes different from the design of the CPU is unable to get the code or buy, there are only IA-64 instruction set architecture manual. So, in fact a large selection of national defense science and technology hardest way, the complete set of instructions from the manual start forward design IA-64 processor, the world's most sought-after. The outcome of this project is also quite tragic, two-year extension was the subject of acceptance, although the final chip index reached the acceptance requirements of the project, but from the real business is still a long way to go. At this stage, national defense science and technology as a great revolutionary idealists, With a cavity blood went to the front line. But the fact is, John Hennessy and David Patterson's books and abacus column to eat again through the book, not as a real sea swim two back and forth. It is said to make the big step on mine defense technology, not branch prediction, pipeline control, arithmetic unit, memory access these standard parts, but DFT. Because I heard did not do DFT, this is compatible with IA-64-made CPU spent a great deal of effort was positioned a few bug, finally able to workaround using the software. Although the project is not successful, but a large National Defense Science and Technology was very productive in the process. On the one hand, a large defense science and technology forward design team has begun to take shape, on the other hand, in this process, the results are also derived some small surprises. A research group designed the Galaxy vault custom 32-bit embedded processor instruction set, a research group designed the ARMv7 instruction set compatible processor nnARM, almost like performance ARM9, and the source code into the open source community for people to download for free . In the spirit of gossip in the end, it is said that nnARM lawyer's letter also drew ARM legal affairs, national defense science and technology but ignore large, as to why you know. Brain research group make up about expression, it should be: x86, IA-64 I have done, you were unwanted ARM instruction set Niubi what?
This is the first phase of several state-backed team there is also a relatively fast hardware, it is a high-performance Shanghai Shen Wei. In addition to its background regressed, where he said he regressed it refers to the design method adopted in the first phase of very fast hardware, but also with a relatively large idealism. While it's logical design from alpha 21264, but the way he uses the physical design of the unit is not ready to take the library synthesis and optimization, but directly work with Foundry custom cell libraries optimized CPU. The benefit of this is obvious, can improve the chip frequency, to optimize power consumption in 2008, Shen Wei 2 on 0.13um process to do about 1.4GHz, became the leader, then other domestic counterparts still in the hundreds of MHz (of course, and there are different lines, such as micro-structural design, it does not mean that the gap between them. For example, the use of relatively deep pipeline frequency is easy to get on, but the performance is not necessarily high). But this problem is obvious, which means that Shen Wei have to pay a huge effort to study the process parameters Foundry, and then customized to meet their needs standard cell. Whether the job is done or Foundry Shen Wei to do, it means bundling longer development cycle and the interests of both sides. Shen Wei is not the IDF, so Foundry willing to cooperate depends Shen Wei can provide much amount was apparently no amount; on the other hand, Shen Wei of pay whether it is worth? Costly energy custom cell libraries greatly extend the product development cycle, and each generation change process to customize the size of a cell library for Shen Wei is clearly unrealistic. Therefore, to the third generation, Shen Wei abandoned the practice of custom cell libraries, to direct the use of foundry standard cell library, upgraded two generations of technology, chip frequency but only up to 1.6GHz. So, Shen Wei also practice early with a little idealism tragedy, the method is right, but the reality is cruel. In any case, this method of physical design is one of the chip to enhance the performance of the technology behind the solution to the current condition of the path, I hope we can continue.
That several subsequent development is about ten years ago, this wave should engage in self-control all know, information is more and more, I think a little gossip online not (grin ~ ~). Godson after the forced industrialization of intellectual property rights and market pressure to buy MIPS licensing and technology (there is a period of time by purchasing technology to solve the ST period), but because of the low-end market failure fought nuclear high base project . Although technically slightly inferior, but institutional mechanisms flexible, general-purpose CPU which in the current market several propaganda do best, industrialization also one step ahead, but unfortunately the brain drain a little bit more (and then later tell people in detail). Shen Wei continued research and development of alpha processor, and has been the darling of the national projects, but for various reasons, never the first generation design approach adopted. Shen Wei processor architecture over many generations of updates, also has a big difference with the original alpha, GM-core CPU is already 16 1621, process 28nm, but the frequency still remain about 1.8GH, while desktop and embedded derivatives chips, used in Taihu light of HPC dedicated Shen Wei 21060 is for the people long face, the product line is considered a very full, but unfortunately could not push industrialization, there are people within the system in addition to the ecological cause unspeakable pain. Large defense technology behind the years, although the successful design of stream processors FT-64 (ISCA then scored his first papers continent, regarded as a pioneer in supercomputing accelerator or martyrs), but only in ultra-count using her as an accelerator and did not cause too much waves. Defense Science and Technology in big defeat on IA-64, IA-64 itself plus the increasingly decadent, prompting the Defense Science and Technology Sharply SPARC, launched two new SPARC chip for ultra-counted. I do not know the reason is not remote territories, to take on the feeling of national projects is always worse then breath. Ark can be found in the sink like a stone Jinian Wen Liang Ning " episode on homemade chips and operating systems ." Jushi after a failed nuclear high base industrialization projects, but also no longer Zhanre general-purpose CPU in this area, moved to other applications.
Whether it is a CPU design or reverse forward design, as long as the full control of its functional design, are to meet the main demands of self-control for the safety of this goal - no subjective malicious backdoor. Of course, there is another security risk, which is designed to introduce a limited ability unintentional loopholes, which are closely related with the design ability, Do not you see Intel to play a lifetime eagle, eagle have been pecked the eyes (see the specter of the beginning of 2018 and blown vulnerabilities ), not to mention the country of these was a toddler. Therefore, domestic CPU design to learn a lot, do not be too arrogant, that pay tuition or to pay.
In the first decade of China-made CPU, full of desolation and barbarism, a failure then a failure has burning passion, but also Unspoken Jiaochen, there's Tough out at large, but also the cover of darkness dirty, but needless to say, China's CPU design fire laid, CPU for the Chinese people no longer far away, no longer just a black box, not smoke and mirrors, China began the journey towards the sea stars, but the key is They have their own wave of troops. If the heart, dream on, man, I hope in.