This series proposes the implementation of a remoteproc tee driver to communicate with a TEE trusted application responsible for authenticating and loading the remoteproc firmware image in an Arm secure context.
1) Principle:
The remoteproc tee driver provides services to communicate with the OP-TEE trusted application running on the Trusted Execution Context (TEE). The trusted application in TEE manages the remote processor lifecycle:
- authenticating and loading firmware images, - isolating and securing the remote processor memories, - supporting multi-firmware (e.g., TF-M + Zephyr on a Cortex-M33), - managing the start and stop of the firmware by the TEE.
2) Format of the signed image:
Refer to: https://github.com/OP-TEE/optee_os/blob/master/ta/remoteproc/src/remoteproc_...
3) OP-TEE trusted application API:
Refer to: https://github.com/OP-TEE/optee_os/blob/master/ta/remoteproc/include/ta_remo...
4) OP-TEE signature script
Refer to: https://github.com/OP-TEE/optee_os/blob/master/scripts/sign_rproc_fw.py
Example of usage: sign_rproc_fw.py --in <fw1.elf> --in <fw2.elf> --out <signed_fw.sign> --key ${OP-TEE_PATH}/keys/default.pem
5) Impact on User space Application
No sysfs impact.the user only needs to provide the signed firmware image instead of the ELF image.
For more information about the implementation, a presentation is available here (note that the format of the signed image has evolved between the presentation and the integration in OP-TEE).
https://resources.linaro.org/en/resource/6c5bGvZwUAjX56fvxthxds
Arnaud Pouliquen (4): remoteproc: Add TEE support dt-bindings: remoteproc: add compatibility for TEE support remoteproc: stm32: create sub-functions to request shutdown and release remoteproc: stm32: Add support of an OP-TEE TA to load the firmware
.../bindings/remoteproc/st,stm32-rproc.yaml | 53 ++- drivers/remoteproc/Kconfig | 10 + drivers/remoteproc/Makefile | 1 + drivers/remoteproc/stm32_rproc.c | 233 +++++++++-- drivers/remoteproc/tee_remoteproc.c | 393 ++++++++++++++++++ include/linux/tee_remoteproc.h | 99 +++++ 6 files changed, 742 insertions(+), 47 deletions(-) create mode 100644 drivers/remoteproc/tee_remoteproc.c create mode 100644 include/linux/tee_remoteproc.h