[PATCH v2 06/11] efi_loader: move runtime variable read helpers to efi_variable.c

[Ilias Apalodimas]

Hi Harsiman

On Thu, 14 May 2026 at 15:50, Harsimran Singh Tungal
<harsimransingh.tungal at arm.com> wrote:
>
> Relocate the generic runtime variable read helpers from
> efi_var_common.c to efi_variable.c.
>
> efi_var_common.c is always built, while efi_variable.c is only built
> when CONFIG_EFI_MM_COMM_TEE is unset. Earlier patches in this series
> add TEE/FF-A-specific runtime read helpers in efi_variable_tee.c.
> Leaving the generic definitions in efi_var_common.c would therefore
> cause a symbol clash in EFI_MM_COMM_TEE builds.
>
> Move efi_get_variable_runtime() and
> efi_get_next_variable_name_runtime() into efi_variable.c so the
> non-TEE backend keeps the generic memory-backed implementations,
> while the TEE/FF-A backend continues to provide its own runtime read
> helpers in efi_variable_tee.c.
>
> Signed-off-by: Harsimran Singh Tungal <harsimransingh.tungal at arm.com>
>
> ---
>
> Changelog:
> ===============
>
> v2:
>
> Ilias, Simon:
>
> - Reword commit message to include relocation of generic non-TEE
>   helpers and broaden the wording to cover both runtime read helpers
>
>  lib/efi_loader/efi_var_common.c | 24 ------------------------
>  lib/efi_loader/efi_variable.c   | 24 ++++++++++++++++++++++++
>  2 files changed, 24 insertions(+), 24 deletions(-)
>
> diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c
> index d63c2d1b1cd..7cbf098c64a 100644
> --- a/lib/efi_loader/efi_var_common.c
> +++ b/lib/efi_loader/efi_var_common.c
> @@ -173,30 +173,6 @@ efi_status_t EFIAPI efi_query_variable_info(
>         return EFI_EXIT(ret);
>  }
>
> -efi_status_t __efi_runtime EFIAPI
> -efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
> -                        u32 *attributes, efi_uintn_t *data_size, void *data)
> -{
> -       efi_status_t ret;
> -
> -       ret = efi_get_variable_mem(variable_name, guid, attributes, data_size,
> -                                  data, NULL, EFI_VARIABLE_RUNTIME_ACCESS);
> -
> -       /* Remove EFI_VARIABLE_READ_ONLY flag */
> -       if (attributes)
> -               *attributes &= EFI_VARIABLE_MASK;
> -
> -       return ret;
> -}
> -

I think I mentioned this on the previous version as well.
The reason that we represent variables in memory at runtime, is that
it works for both secure and non secure world storage. In the secure
world case, Linux scans that OP-TEE can support variables at runtime
and swtiches get/setVariable to point in op-tee functions.
Due to the above we were less strict wth the API, since evenryone just
called the _mem variant for runtime calls and it saved us a function
call.

 If we want to change this, the right fix would be to define _int
variants in the efi_variable.c and efi_variable_tee.c and call them
from efi_var_common.c. This basically boils down to calling the _int
version in efi_get_variable_runtime and efi_get_next_variable_runtime
on the common code.

Thanks
/Ilias


> -efi_status_t __efi_runtime EFIAPI
> -efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
> -                                  u16 *variable_name, efi_guid_t *guid)
> -{
> -       return efi_get_next_variable_name_mem(variable_name_size, variable_name,
> -                                             guid, EFI_VARIABLE_RUNTIME_ACCESS);
> -}
> -
>  /**
>   * efi_set_secure_state - modify secure boot state variables
>   * @secure_boot:       value of SecureBoot
> diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
> index 9923936c1b5..f2e0e1ad4e2 100644
> --- a/lib/efi_loader/efi_variable.c
> +++ b/lib/efi_loader/efi_variable.c
> @@ -579,6 +579,30 @@ efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
>         return EFI_SUCCESS;
>  }
>
> +efi_status_t __efi_runtime EFIAPI
> +efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid,
> +                        u32 *attributes, efi_uintn_t *data_size, void *data)
> +{
> +       efi_status_t ret;
> +
> +       ret = efi_get_variable_mem(variable_name, guid, attributes, data_size,
> +                                  data, NULL, EFI_VARIABLE_RUNTIME_ACCESS);
> +
> +       /* Remove EFI_VARIABLE_READ_ONLY flag */
> +       if (attributes)
> +               *attributes &= EFI_VARIABLE_MASK;
> +
> +       return ret;
> +}
> +
> +efi_status_t __efi_runtime EFIAPI
> +efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
> +                                  u16 *variable_name, efi_guid_t *guid)
> +{
> +       return efi_get_next_variable_name_mem(variable_name_size, variable_name,
> +                                             guid, EFI_VARIABLE_RUNTIME_ACCESS);
> +}
> +
>  /**
>   * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
>   */
> --
> 2.34.1
>