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I am attempting to debug my OS a bit
but I have no idea what the gpf error code is I just know it exists
it is what is automatically pushed onto the stack when a gpf happens..

There are exceptions that push a certain exception-specific error code one the stack. Examples therefore is the gpf and the page fault. Look into the intel manuals to find out what these error codes contain.

To refresh my memory.. The error code has 4 field which is TI, IDT, EXT and the Selector Index field. EXT=1 when the fault was caused by external device, I believe anything but the CPU. When IDT=1 then Selector Index field simply gives you information which IDT Index caused the GPF. If IDT=0 then TI would indicate Selector Index field corresponds to either GDT/LDT. A senerio that I went through making error code information useful is when the PIC was firing spurious interrupts and I did not have a interrupt handler for it, however I had a NP exception handler which I thought would of fired in those circumstances, but insted GPFs were generated. Looking at the error code gives me EXT=1 and IDT=1 Selector Index = 27h which was mapped as IRQ7 and very easy assume the PIC to be causing GPFs. Hope this information helps with debugging with error codes.

yes thank you.. I found it in volume 3,chapter 5 of the intel manual