Hi,

The only reason for this question is learning. I'm trying to handle interrupts. I started with the FreeBSD kernel sources and modified a bit. My code is executed early during the bootstrap process, right after the processor is set in protected mode and most descriptors (IDT, GDT, etc) are set up.

All entries in the IDT point to my own ISR. When executing INTx instructions I see it works fine. However I'm not receiving any hardware interrupts.

I tried issuing a STI instruction to make sure interrupts are enabled and outputting 0x20 to ports 0x20 and 0xA0 to make sure there are no pending EOIs (even if it shouldn't be necessary). However I'm still receiving nothing.

Is there some processor flag I don't know about? What did I miss?
Thanks

Did you initialize the PIC?

Also you have to unmask the interrupts you want to receive. See Interfacing the PC, especially Hardware Interrupts

Ehm... no. This is what I was missing.

It works fine now. Thanks.

Hi irey.
I want to edit the IDT, too. Can you tell me more about?
E.g. the GDT entry (Segment pointing to the IDT) for editing the IDT because I use a LKM to setup a new interrupt framework INT 0x81 and the symbol "idt_table[];" seems not to be reachable at linktime.

Many Thanks in advance.