文档基于一个余从未见过的操作系统 RISC OS，但基本的东西如指令集是跨越厂商和平台的，汇编格式等差异应当不是大问题。余从中选译了指令集部分，没有选取依赖于特定硬件和工具的内容-I have never seen a document based on an operating system, RISC OS, but the basic things such as instruction set across vendors and platforms, the compilation o