Messages in this thread | | | Date | Thu, 04 Apr 2013 13:25:37 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH v2 08/20] x86, ACPI: Find acpi tables in initrd early from head_32.S/head64.c |
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On 03/10/2013 03:25 AM, Pekka Enberg wrote: > > What is preventing us from making the 64-bit variant also work in flat > mode to make the code consistent and not hiding the differences under > the rug? What am I missing here? >
There is no such thing as "flat mode" in 64-bit mode. We use a #PF handler to emulate it, but we add the normal kernel offset when doing so.
In the 32-bit case the problem is that the kernel offset is not available while in linear mode. It *could* be created using segment bases, but that would break Xen, I'm pretty sure, and possibly some other too-clever environments.
-hpa
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