[linux-yocto] [PATCH 2/3] meta: efi-ext.cfg: replace EFI_VARS with EFIVAR_FS

[Bruce Ashfield]

On 2014-03-12, 10:15 AM, Stefan Stanacar wrote:
> Linux kernel exposes EFI variables data to userspace via 2 interfaces:
> - old sysfs-efivars interface (CONFIG_EFI_VARS), populated at /sys/firmware/efi/vars,
> 1024 byte maximum per-variable data size limitation, no UEFI Secure Boot variables support
> and not recommended anymore.
> - new efivarfs interface (CONFIG_EFIVAR_FS), typically mounted like this:
> mount -t efivarfs efivarfs /sys/firmware/efi/efivar
> It was added in 3.8 intended as a replacement for the sysfs-efivars interface,
> has no maximum per-variable size limitation and supports UEFI Secure Boot variables.
> It also allows creating new vars easily, a very useful trick:
> printf "\x07\x00\x00\x00\x00" > /sys/firmware/efi/efivar/myvar-12345678-1234-1234-1234-123456789abc

I haven't looked into it yet, so I'll ask, can both co-exist ? Or
is the most common mount point going to cause problems with a
a conflicting path ?

If so, I'd rather introduce the new one, and keep the old one
around for this 1.6 release, that way I can warn and remove the
existing one.

Cheers,

Bruce

>
> Signed-off-by: Stefan Stanacar <stefanx.stanacar at intel.com>
> ---
>   meta/cfg/kernel-cache/cfg/efi-ext.cfg | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/meta/cfg/kernel-cache/cfg/efi-ext.cfg b/meta/cfg/kernel-cache/cfg/efi-ext.cfg
> index 6371da2..edceb75 100644
> --- a/meta/cfg/kernel-cache/cfg/efi-ext.cfg
> +++ b/meta/cfg/kernel-cache/cfg/efi-ext.cfg
> @@ -10,5 +10,5 @@ CONFIG_PARTITION_ADVANCED=y
>   # Add support for optional EFI features
>   CONFIG_FRAMEBUFFER_CONSOLE=y
>   CONFIG_FB_EFI=y
> -CONFIG_EFI_VARS=y
> +CONFIG_EFIVAR_FS=y
>   CONFIG_EFI_PARTITION=y
>