Messages in this thread |  | | Date | Mon, 16 Jun 2008 03:06:29 -0500 | From | Paul Jackson <> | Subject | Re: [PATCH 5/8] x86 boot: remap efi systab runtime from phys to virt |
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Huang wrote: > > efi.systab = (efi_system_table_t *) (unsigned long) systab; > > + efi.systab->runtime = __va(efi.systab->runtime); > > } > > } > > Why do you need this?
I need this so that my kernel can callback into EFI runtime services post-boot.
> This should be done by firmware in > efi_set_virtual_address_map().
I don't understand this comment. I don't see any routine named 'efi_set_virtual_address_map()' in the kernel. I do see virt_* and phys_* variants of that name; did you mean one of those?
In any case, I don't understand how this could "be done by firmware." It is the kernel that is mapping in the firmware somehow to support EFI runtime services.
> And this doesn't work on i386, because > runtime code/data area may be not in identity map area (that is > 768M).
Ok ... what code should we add for i386? Would it be code like I see above in this efi_enter_virtual_mode() routine:
if (PFN_UP(end) <= max_pfn_mapped) va = __va(md->phys_addr); else va = efi_ioremap(md->phys_addr, size);
I could write similar code for remapping efi.systab->runtime, but I could not test such code -- could you assist me in that?
-- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson <pj@sgi.com> 1.940.382.4214
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