x86 assembly language

1. Summarize real mode (16-bit), 16-bit protection mode, 32-bit protection mode in one sentence.

16-bit real mode, addressing: Sg+offset (16-bit), segment register +offset is memory address, no segment description table, direct read memory, segment only logical meaning (code snippet?). Data segment? such as

16 is the protected mode, addressing the Sg+offset (16-bit), the segment register is the ID of the Segment Description table, the table entry records the true segment address, and whether the segment is in memory. (can provide a larger memory space than the physical address)! And the segment descriptor adds access bits, which characterize read-only and read-write.

32-bit protected mode, addressing Sg+offset (32-bit), segment register is the ID of a segment Description table, and a segment is divided into 32/4kb pages. is the page in memory, access control, in the Segment descriptor or page description?

x86 assembly language