Protection Control Instructions

All instructions on this page require 286 or higher CPU.

LGDT src       load Global Descriptor Table from 6-byte table at src
SGDT dest      store 6-byte Global Descriptor Table to memory at dest

LIDT src       load Interrupt Descriptor Table from 6-byte table at src
SIDT dest      store 6-byte Interrupt Descriptor Table to memory at dest

LLDT src       load Local Descriptor Table (GDT selector) from reg/mem16
SLDT dest      store Local Descriptor Table register into dest (r/m16)

LMSW src       load Machine Status Word (use to enter protected mode)
SMSW src       store Machine Status Word to reg/mem16

LTR  src       load Task Register (GDT selector) from reg/mem16
STR  dest      store Task Register to reg/mem16

LAR  dest,src  load high-byte of dest with Access Rights of src descriptor

LSL  dest,src  load dest with Segment Limit of descriptor named by src

ARPL lvl       Adjust Requested Privilege Level to higher of current or lvl

VERR seg       Sets ZF to ZR if task has read privileges for segment seg

VERW seg       Sets ZF to ZR if task has write privileges for segment seg
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