[patch 7/7 v2] x86: add xloadflags bit for efi runtime support on kexec

[Matt Fleming]

On Tue, 05 Nov, at 04:20:14PM, dyoung at redhat.com wrote:
> Old kexec-tools can not load new kernel. The reason is previously kexec-tools
> do not fill efi_info in x86 setup header thus efi init fail and switch
> to noefi boot. In new kexec-tools it will by default fill efi_info and
> pass other efi required infomation to 2nd kernel so kexec kernel efi
> initialization will success finally.
> 
> To prevent from breaking userspace, add a new xloadflags bit so kexec-tools
> will check the flag and switch to old logic.
> 
> Signed-off-by: Dave Young <dyoung at redhat.com>
> ---
>  arch/x86/boot/header.S                |    9 ++++++++-
>  arch/x86/include/uapi/asm/bootparam.h |    1 +
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> --- linux-2.6.orig/arch/x86/boot/header.S
> +++ linux-2.6/arch/x86/boot/header.S
> @@ -391,7 +391,14 @@ xloadflags:
>  #else
>  # define XLF23 0
>  #endif
> -			.word XLF0 | XLF1 | XLF23
> +
> +#if defined(CONFIG_X86_64) && defined(CONFIG_EFI)

&& defined(CONFIG_KEXEC) ?

> +# define XLF4 XLF_EFI_KEXEC
> +#else
> +# define XLF4 0
> +#endif
> +

-- 
Matt Fleming, Intel Open Source Technology Center