Re: EFI runtime-services on x86_64

From: Feng Tang
Date: Sun Aug 01 2010 - 22:16:50 EST


Hi Bjorn,

On Sat, 31 Jul 2010 04:58:48 +0800
Bjorn Helgaas <bjorn.helgaas@xxxxxx> wrote:

> Hello Feng,
>
> Can you educate me about your commit 772be899bc, "86: Make EFI RTC
> function depend on 32bit again"?
>
> It adds "#ifdef CONFIG_X86_32" to avoid using efi_get_time() and
> efi_set_rtc_mmss(), but there's no explanation of *why* those services
> only work on 32-bit.
>
> Is this an EFI spec limitation? Do the other EFI runtime services
> work on 64-bit, since you didn't touch them? Or do we just not use
> any of the others?
>

Commit 772be899bc, "86: Make EFI RTC function depend on 32bit again" is
a regression fix for 7bd867d "x86: Move get/set_wallclock to x86_platform_ops".
These 2 commits just abstract the rtc service for legacy x86 PC/EFI/Virtualiation
kernel, and has no functional change to existing code.

I'm not familiar with EFI, but my understanding is current EFI code in
kernel only provides the get/set_time service for x86_32 platform.

Cc Ying who is more familiar with EFI than me.

Thanks,
Feng
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/