Best for affordability
The main rule for data access is max(CPL, RPL) ≤ DPL. For code transfers, the rules get considerably more complex -- conforming segments, call gates, and interrupt gates each have different privilege and state validation logic. If all these checks were done in microcode, each segment load would need a cascade of conditional branches: is it a code or data segment? Is the segment present? Is it conforming? Is the RPL valid? Is the DPL valid? This would greatly bloat the microcode ROM and add cycles to every protected-mode operation.
，这一点在91视频中也有详细论述
90年后的今天，中国式现代化已经展开壮美画卷并呈现出无比光明灿烂的前景。，更多细节参见搜狗输入法下载
2024年12月23日 星期一 新京报