Hi Simon, thanks for the cc

Tasos thanks for the report. Here's what happens here

On Fri, 18 Nov 2022 at 22:50, Simon Glass sjg@chromium.org wrote:

+Ilias Apalodimas

On Tue, 15 Nov 2022 at 23:12, Tasos Terzidis terzanasta@gmail.com wrote:

...

Hello,

I tried to use a tpm2 command for reading the NV memory index of an slb9670 TPM.

I noticed in file cmd/tpm-v2.c, that the command tpm2 nv_read_value (as tpm nv_read_value)

is not implemented. In file lib/tpm-v2.c there is the tpm2_nv_read_value function.

Do you plan to implement the command tpm2 nv_read_value in the future ?

That should be relatively easy to plug in and test. The functionality already exists in the TPM API (tpm_nv_read_value support v1 & v2). However no one has added it in 'tpm2' functions which explains what you see below.

The entry point for the tpm command is 'cmd/tpm-common.c'. In that code we try to figure out if we are talking to a tpmv1 or v2. In your case it's a v2 and you get back a usage message since reading nvram isn't implemented yet.

...

Then I used the

tpm nv_read_value index addr count

  "Read <count> bytes from space <index> to memory address <addr>".

The syntax I used is

tpm nv_read_value 0x100000000 0x30000000 20

I’m trying to read 32 bytes from 0x100000000 index nv memory of TPM

to 0x30000000 memory of u-boot

U-boot can’t understand the command and returns the help listing all the commands for tpm.

I also used

tpm nv_read_value 0x0 0x30000000 20

0x0 as an offset to 0x100000000 index of NV memory (following the syntax of tpm2_nvread command o TSS tpm –tools)

Same result, list of commands for tpm

Other commands of tpm such as tpm2 pcr read or extend functions as expected in u-boot environment

I can’t understand what I do wrong

Thanks /Ilias

...

Thank you

Tasos Terzids