Function:

Loads the limits of a segment in protected mode by reading GDT entry reg/mem
into reg1. Proper completion generates ZF=1, otherwise ZF=0.

Some 386es allow access to selector 0 in the GDT leaving ZF=1.
Normally this should not be possible and produce the condition ZF=0.

Workaround would be to create an entry 0 in the GDT that consists of only
zeroes. This will cause access with a selector of 0 to fail and
produce ZF=0.

Some 386es leave SP/ESP corrupted after successful completion of LSL, when
LSL is followed by an explicit stack reference, using instructions like
CALL, ENTER, LEAVE, IRET, RET, PUSH, POP, PUSHA, POPA, PUSHF and POPF.
System-induced exceptions or interrupts however do not corrupt SP/ESP in
that case. A workaround is to code a NOP after LSL.

A data breakpoint set to the mem16 operand of LSL can be missed on some
386es if the segment with the selector at mem16 is not accessible.
(see also <debugging>)




MOV   Move data to and from registers and or memory
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