实模式

保护模式

寄存器
段寄存器
格式

segment descriptor
ss (stack segment)
tss ( task state segment)

esp(stack pointer)
ebp(stack-frame base pointer)
segment selector

general-purpose register
segment register
EFLAGS (program status and control) register
EIP (instruction pointer) register
image.png

call

call between different privilege level
near call

far call