On Thu, Jul 27, 2023 at 05:07:11PM +0100, Abdellatif El Khlifi wrote:
Add MM communication support using FF-A transport
This feature allows accessing MM partitions services through EFI MM communication protocol. MM partitions such as StandAlonneMM or smm-gateway secure partitions which reside in secure world.
An MM shared buffer and a door bell event are used to exchange the data.
The data is used by EFI services such as GetVariable()/SetVariable() and copied from the communication buffer to the MM shared buffer.
The secure partition is notified about availability of data in the MM shared buffer by an FF-A message (door bell).
On such event, MM SP can read the data and updates the MM shared buffer with the response data.
The response data is copied back to the communication buffer and consumed by the EFI subsystem.
MM communication protocol supports FF-A 64-bit direct messaging.
Signed-off-by: Abdellatif El Khlifi abdellatif.elkhlifi@arm.com Tested-by: Gowtham Suresh Kumar gowtham.sureshkumar@arm.com Reviewed-by: Simon Glass sjg@chromium.org Cc: Tom Rini trini@konsulko.com Cc: Ilias Apalodimas ilias.apalodimas@linaro.org Cc: Jens Wiklander jens.wiklander@linaro.org
Changelog:
v17:
- show a debug message rather than an error when FF-A is not detected
[snip]
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index c5835e6ef6..8fbadb9201 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -55,13 +55,53 @@ config EFI_VARIABLE_FILE_STORE stored as file /ubootefi.var on the EFI system partition.
config EFI_MM_COMM_TEE
- bool "UEFI variables storage service via OP-TEE"
- depends on OPTEE
- bool "UEFI variables storage service via the trusted world"
- depends on OPTEE && ARM_FFA_TRANSPORT
You didn't get my changes in here however. If you can do EFI_MM_COMM_TEE without ARM_FFA_TRANSPORT (as lx2160ardb_tfa_stmm_defconfig does) then you don't make this option depend on EFI_MM_COMM_TEE. If FF-A is only for use here, you make FF-A depend on this, and the FF-A specific variable depend on ARM_FFA_TRANSPORT.