Abstraction & ISA

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Abstraction 真是好重要好重要的概念.

感觉 Computer Organization 里最重要的一个概念就是ISA, 它是软硬件的中间层. 软件不必知道底层的硬件, 只需知道ISA就可以运行; 而硬件只需遵从某个 ISA (如 x86, risc-v), 不必考虑上层的软件.

The combination of the basic instruction set (the ISA) and the operating system interface is called the application binary interface (ABI).

ABI—The user portion of the instruction set plus the operating system interfaces used by application programmers. Defines a standard for binary portability across computers.