Re: optee-based efi runtime variable service on TI j784s4 platforms

[Ilias Apalodimas]

Hi Enric,

On Fri, 8 Nov 2024 at 12:26, Enric Balletbo i Serra <eballetb@xxxxxxxxxx> wrote:
>
> Hi all,
>
> I'm looking for any advice/clue to help me to progress on enabling
> TEE-base EFI Runtime Variable Service on TI a j784s4 platforms.
>
> I basically followed the steps described in u-boot documentation [1],
> I enabled some debugging messages but I think I'm at the point that
> the problem might be in the StandaloneMM application, and I'm not sure
> how to debug it.
>
> What I see is that when I run the tee-supplicant daemon, it looks like
> the tee_client_open_session() call loops forever and the tee_stmm_efi
> driver never ends to probe.
>
> With debug enabled I got the following messages.

I assume reading and storing variables already works in U-Boot right?

>
> # tee-supplicant
> D/TC:? 0 tee_ta_init_session_with_context:557 Re-open trusted service
> 7011a688-ddde-4053-a5a9-7b3c4ddf13b8
> D/TC:? 0 load_stmm:297 stmm load address 0x40004000
> D/TC:? 0 spm_handle_scall:859 Received FFA version
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
> D/TC:? 0 spm_handle_scall:867 Received FFA direct request
>
> And tracing the function calls gives me that:
>
>       tee_stmm_efi_probe() {
>              tee_client_open_context() {
>                optee_get_version() {
>                  tee_get_drvdata(); (ret=0xffff000002e55800)
>                } (ret=0xd)
>                tee_ctx_match(); (ret=0x1)
>                optee_smc_open() {
>                  tee_get_drvdata(); (ret=0xffff000002e55800)
>                  optee_open() {
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                  } (ret=0x0)
>                } (ret=0x0)
>              } (ret=0xffff000004e71c80)
>              tee_client_open_session() {
>                optee_open_session() {
>                  tee_get_drvdata(); (ret=0xffff000002e55800)
>                  optee_get_msg_arg() {
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    tee_shm_get_va(); (ret=0xffff000002909000)
>                  } (ret=0xffff000002909000)
>                  tee_session_calc_client_uuid(); (ret=0x0)
>                  optee_to_msg_param(); (ret=0x0)
>                  optee_smc_do_call_with_arg() {
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    tee_shm_get_va(); (ret=0xffff000002909000)
>                    tee_shm_get_va(); (ret=0xffff000002909060)
>                    optee_cq_wait_init(); (ret=0xffff000002e55910)
>                    optee_smccc_smc(); (ret=0xffff0004)
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    optee_smccc_smc(); (ret=0xffff0004)
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    optee_smccc_smc(); (ret=0xffff0004)
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    optee_smccc_smc(); (ret=0xffff0004)
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    optee_smccc_smc(); (ret=0xffff0004)
>      ... continues sending this forever ...
>      ... Hit ^C to stop recording ...
>                    tee_get_drvdata(); (ret=0xffff000002e55800)
>                    optee_smccc_smc() {
>
> [1] https://docs.u-boot.org/en/latest/develop/uefi/uefi.html#using-op-tee-for-efi-variables
>
> Thanks in advance,

The most common problem with this is miscompiling the tee_supplicant
application.
Since we don't know if the system has an RPMB, we emulate it in the
tee_supplicant. How did you get the supplicant and can you check if it
was compiled with RPMB_EMU=0 or 1?

Thanks
/Ilias

>    Enric
>