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 find CONFIG_EFIVAR_FS very useful for EFI images and I'd like to have it enabled by default. For example with gummiboot you can use the LoaderEntryOneShot to tell it the entry identifier to select at the next and only the next bootup, and I plan to use that in automated testing. They both can co-exist - but they shouldn't both be active / mounted (the problem isn't the mount point but data inconsistency) so we enable them as modules and have the new one as the default and the old one around for anyone that needs it. Signed-off-by: Stefan Stanacar <stefanx.stana...@intel.com> --- meta/cfg/kernel-cache/cfg/efi-ext.cfg | 2 +- meta/cfg/kernel-cache/cfg/efi.cfg | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/meta/cfg/kernel-cache/cfg/efi-ext.cfg b/meta/cfg/kernel-cache/cfg/efi-ext.cfg index 6371da2..9569788 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_EFI_VARS=m CONFIG_EFI_PARTITION=y diff --git a/meta/cfg/kernel-cache/cfg/efi.cfg b/meta/cfg/kernel-cache/cfg/efi.cfg index e2ecc18..33753cc 100644 --- a/meta/cfg/kernel-cache/cfg/efi.cfg +++ b/meta/cfg/kernel-cache/cfg/efi.cfg @@ -7,3 +7,4 @@ CONFIG_ACPI=y # Enable basic EFI support CONFIG_EFI=y CONFIG_EFI_STUB=y +CONFIG_EFIVAR_FS=m -- 1.8.5.3 -- _______________________________________________ linux-yocto mailing list linux-yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/linux-yocto
