Request Privellege Level (RPL)?
Request Privellege Level (RPL)?
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Last edited by Perica on Sun Dec 03, 2006 8:59 pm, edited 2 times in total.
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Re:Request Privellege Level (RPL)?
iirc, the Requested Priviledge Level (rPL) is the small 2-bits tag that comes with every selector in the segment registers.
What the weird things from the manual extract means is that if you have a data descriptor at index 0x18 in your GDT which is a DPL3 segment, you cannot use mov ds,0x18 but you must use mov ds,0x1b instead, so that the RPL reflects the DPL. If this isn't the case, then the segment loading operation will raise a GPF.
The only situation where you could possibly "choose" your DPL level would be the case where you're calling/jumping to a conforming code segment, but as i haven't really used them so far, i can't be sure
What the weird things from the manual extract means is that if you have a data descriptor at index 0x18 in your GDT which is a DPL3 segment, you cannot use mov ds,0x18 but you must use mov ds,0x1b instead, so that the RPL reflects the DPL. If this isn't the case, then the segment loading operation will raise a GPF.
The only situation where you could possibly "choose" your DPL level would be the case where you're calling/jumping to a conforming code segment, but as i haven't really used them so far, i can't be sure