Hello all:
Look:
jump32 macro selector,offsetv
db 66h
db 0eah ;jmp
dd offsetv ;4 bytes offset address
dw selector
endm
I find that these codes are unassembled:jmp selector:offsetv,and the
codes are embedded in 16-bit real mode,then look:
jump16 macro selector,offsetv
db 66h
db 0eah ;jmp
dw offsetv ;2 bytes offset address
dw selector
endm
but these codes aren't unassembled:jmp selector:offsetv in 32-bit p-mode,
I want to know which is operand,selector or offsetv?And which operand
is influenced by the prefix 66h,selector or offsetv?
How the prefix is interpreted depends on the current mode of the processor. A disassembler looking at such code would need to know the context (16/32-bit) in effect to display the correct interpretation.
A segment/selector is always viewed as a 16-bit value, the address is what is 16 or 32-bit. The prefix inverts the normal sense the processor is working with.