On Wed, 3 Jul 2019 at 13:42, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Hi Thirupathaiah,
(+Joakim)
On Wed, 3 Jul 2019 at 09:58, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Hi Thirupathaiah,
First of all, Thanks a lot for trying to test the driver.
np
[...]
I managed to do some quick testing in QEMU. Everything works fine when i build this as a module (using IBM's TPM 2.0 TSS)
- As module
# insmod /lib/modules/5.2.0-rc1/kernel/drivers/char/tpm/tpm_ftpm_tee.ko # getrandom -by 8 randomBytes length 8 23 b9 3d c3 90 13 d9 6b
- Built-in
# dmesg | grep optee ftpm-tee firmware:optee: ftpm_tee_probe:tee_client_open_session failed, err=ffff0008
This (0xffff0008) translates to TEE_ERROR_ITEM_NOT_FOUND.
Where is fTPM TA located in the your test setup? Is it stitched into TEE binary as an EARLY_TA or Is it expected to be loaded during run-time with the help of user mode OP-TEE supplicant?
My guess is that you are trying to load fTPM TA through user mode OP-TEE supplicant. Can you confirm?
I tried both
Ok apparently there was a failure with my built-in binary which i didn't notice. I did a full rebuilt and checked the elf this time :)
Built as an earlyTA my error now is: ftpm-tee firmware:optee: ftpm_tee_probe:tee_client_open_session failed, err=ffff3024 (translates to TEE_ERROR_TARGET_DEAD) Since you tested it on real hardware i guess you tried both module/built-in. Which TEE version are you using?
U-boot and Linux driver stacks work seamlessly without dependency on supplicant.
Is this true?
It looks like this fTPM driver can't work as a built-in driver. The reason seems to be secure storage access required by OP-TEE fTPM TA that is provided via OP-TEE supplicant that's not available during kernel boot.
Snippet from ms-tpm-20-ref/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/fTPM.c +145:
// If we fail to open fTPM storage we cannot continue. if (_plat__NVEnable(NULL) == 0) { TEE_Panic(TEE_ERROR_BAD_STATE); }
So it seems like this module will work as a loadable module only after OP-TEE supplicant is up.
-Sumit
Thanks /Ilias