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which instruction could be used in PMode
Posted: Thu Jul 15, 2004 3:17 am
by chen17981
hi, I just want to know which instructions could be used in PMode. Now I am very confused with instruction "outb" and "intb", in some codes I found them in PMode, but some documents told me that these instructions could not be used in Pmode.
Re:which instruction could be used in PMode
Posted: Thu Jul 15, 2004 4:19 am
by DennisCGc
Those instructions could be used, when you're using it in privilige level 0. (it depends whether your IOPL flag set to).
like: if IOPL flag is set to 1 privilige levels 0 and 1 can use those instruction, if set to (IOPL flag) 2 levels 0,1 and 2 can use it, etc.
and it's btw "inb"
Re:which instruction could be used in PMode
Posted: Thu Jul 15, 2004 6:54 pm
by chen17981
Thank you. I will try