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Document for new version IO APIC?

Posted: Thu Jan 18, 2024 7:13 am
by songziming
Hi, asking again.

Where can I find documents about programming new version of IO APIC?

I have the document for 82093AA, but it only support 8-bit APIC ID. I want to support x2APIC, whose APIC ID is 32-bit.

I checked Linux source code, and it mentioned Intel ICH Specs, but I can only find its datasheets (https://www.intel.sg/content/dam/doc/da ... asheet.pdf). The datasheet only tells me about interrupt mapping, but didn't tell me where to access those registers.

For example, I saw newer version of IO APIC have EOI register, I couldn't find its mapped address. And I still don't know the redirect entry format that supports 32-bit APIC ID.

Reading from Linux kernel can be a choice, but I still want an official document.

Thanks.

Re: Document for new version IO APIC?

Posted: Thu Jan 18, 2024 7:35 am
by songziming
I found the info in section 13.5 of datasheet. I didn't read careful enough.

Its strange they put IO APIC under chapter "LPC Interface Bridge Registers (D31:F0)".