Re: [tip:x86/microcode] x86/microcode_intel_early.c: Early updateucode on Intel's CPU

[Yinghai Lu]

On Tue, Dec 11, 2012 at 3:57 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Well, we could invoke it on the bootloader page tables, but as you say
> it may not be a good idea... depending on how much memory we may be
> talking about.  One solution -- which I have to admit is starting to
> sound really good -- is to set up a #PF handler which cycles through a
> set of page tables and creates a "virtual identity map"... it does have
> the advantage of making the entire physical address space available
> without any additional funnies.

so that #PF handler will work before
arch/x86/kernel/setup.c::setup_arch/early_trap_init

early_strap_intit will install another handler there for #PF

for 64bit, moving early_ioremap_init ahead is very simple, like attach patch

but for 32 bit looks like it is not that easy.

Attachment: early_ioremap_head64.patch
Description: Binary data