Messages in this thread |  | | From | Daniel Phillips <> | Subject | Re: interrupt magic | Date | Sat, 23 Sep 2000 21:11:30 +0200 |
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Anton Altaparmakov wrote: > > I can't remember anything about protected mode interrupt handlers nor have > I ever looked at Linux interrupt handling but at least in real mode from my > good old PC/DOS programming days I seem to remember that if you are hooking > a hardware interrupt vector then you have to issue a end of interrupt (EOI) > to the 8259A interrupt controller (PIC) before doing the iret, for example > like so: > > ; Note: this uses "dst, src" operand ordering not the > ; "reversed" ordering used by gcc asm. > push ax > mov al,20h ; Nonspecific EOI > out 20h,al ; Write PIC output control word OCW2 > pop ax > iret > > Might this be the problem (or whatever the equivalent specific is in Linux > / pmode)?
Oh yes, nothing has changed, this is still required, and don't forget to signal the slave PIC as well if your IRQ is 8 or higher. Lovely stuff. :P
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