[Tpm2] help regarding how to create NV under platform hierarchy

Hi Folks,
I am new to tpm2.


I am trying to create NV index under platform hierarchy using tpm2-tools but getting below error.

tpm2_nvdefine 0x01000000 -C p -s 32 -a "ppwrite|ppread|platformcreate" WARNING:esys:src/tss2-esys/api/Esys_NV_DefineSpace.c:337:Esys_NV_DefineSpace_Finish() Received TPM Error ERROR:esys:src/tss2-esys/api/Esys_NV_DefineSpace.c:122:Esys_NV_DefineSpace() Esys Finish ErrorCode (0x000009a2) ERROR: Failed to define NV area at index 0x1000000 ERROR: Esys_NV_DefineSpace(0x9A2) - tpm:session(1):authorization failure without DA implications ERROR: Failed to create NV index 0x1000000.


need help regarding above error and how to create nv index in platform hierarchy
if I create nv index in owner hierarchy tmp2_clear will remove the NV index which i don't want to happen so I am trying to create in platform hierarchy.

are there any ways to store a symmetric key in TPM for external use other than nv index?

Thanks,
Vamsee Krishna.