On Wed, 24 May 2023 at 10:01, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Hi Sumit,
On Wed, 24 May 2023 at 10:56, Sumit Garg sumit.garg@linaro.org wrote:
On Tue, 23 May 2023 at 14:36, Masahisa Kojima masahisa.kojima@linaro.org wrote:
This series introduces the tee based EFI Runtime Variable Service.
The eMMC device is typically owned by the non-secure world(linux in this case). There is an existing solution utilizing eMMC RPMB partition for EFI Variables, it is implemented by interacting with OP-TEE, StandaloneMM(as EFI Variable Service Pseudo TA), eMMC driver and tee-supplicant. The last piece is the tee-based variable access driver to interact with OP-TEE and StandaloneMM.
Changelog: v3 -> v4:
- replace the reference from EDK2 to PI Specification
- remove EDK2 source code reference comments
- prepare nonblocking variant of set_variable, it just returns EFI_UNSUPPORTED
- remove redundant buffer size check
- argument name change in mm_communicate
- function interface changes in setup_mm_hdr to remove (void **) cast
I don't have detailed insights into how EFI spec mandates StandaloneMM should be implemented. But utilizing OP-TEE as the underlying transport here looks fine to me. FWIW,
For the series: Acked-by: Sumit Garg sumit.garg@linaro.org
Thanks!
FWIW the PI spec describes some of the functionality and how that should be accessed. There's a EFI_MM_COMMUNICATION_PROTOCOL which is not used here. Instead the entry point is via an SMC to op-tee and the payload adheres to what the PI spec describes in its EFI_MM_COMMUNICATE_HEADER
Thanks for the resend
Could you please double check whether this needs any changes in relation to this patch?
https://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git/commit/?id=d86ff...