Re: [PATCH v2 0/3] TPM2.0: Added eventlog support for TPM2.0

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Wed, Aug 17, 2016 at 11:28:51AM +0530, Nayna wrote:
> Hi Jarkko,
> 
> My response inline.
> 
> On 08/17/2016 09:45 AM, Jarkko Sakkinen wrote:
> >On Tue, Aug 16, 2016 at 10:48:53PM +0300, Jarkko Sakkinen wrote:
> >>On Wed, Aug 17, 2016 at 12:46:40AM +0530, Nayna wrote:
> >>>Hi Jarkko,
> >>>
> >>>
> >>>
> >>>On 08/16/2016 02:56 AM, Jarkko Sakkinen wrote:
> >>>>On Fri, Aug 12, 2016 at 06:02:00PM +0530, Nayna wrote:
> >>>>>>>Jarkko, Please let me know if it doesn't answer your question. </nayna>
> >>>>>>
> >>>>>>1. EFI does not pass the log by any means AFAIK before a boot loader
> >>>>>>    calls ExitBootServices().
> >>>>>
> >>>>>So, is current TCPA support only for TPM1.2 ?
> >>>>
> >>>>TCPA ACPI table is only available for TPM 1.2.
> >>>>
> >>>>TPM2 ACPI table does not provide a memory ref for the event log.
> >>>>
> >>>>>#2, TCG Spec http://www.trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf
> >>>>>talks about
> >>>>>EFI_TCG2_PROTOCOL.GetEventLog (Section 6.5), what is that supposed to do ?
> >>>>
> >>>>Direct quote from your reference:
> >>>>
> >>>>"Boot Service Drivers are terminated when ExitBootServices() is called
> >>>>and all memory resources consumed by the Boot Services Drivers are
> >>>>released for use in the operating system environment."
> >>>
> >>>Thanks Jarkko, I understand now what you meant.
> >>>>
> >>>>>>2. I do not have any system with TPM2 that uses DT. And as I stated
> >>>>>>    before you didn't have any reference where you derived the DT
> >>>>>>    node fields.
> >>>>>
> >>>>>As per Device Tree, so this is the new node introduced in the device tree to
> >>>>>support TPM. And the fields are defined maintaining the requirements from
> >>>>>ePAPR specification.
> >>>>
> >>>>What is ePAPR specification? Can you provide a reference?
> >>>
> >>>PowerPC systems are based on device tree and derive that from ePAPR
> >>>specification, link below for ePAPR specification..
> >>>
> >>>https://www.power.org/documentation/power-org-standard-for-embedded-power-architecture-platform-requirements-epapr-v1-1-2/
> >>
> >>Thanks. I'll check that through when I review the next version.
> >
> >This specification did not define the TPM binding for DT. I searched
> >with "tpm" keyword from the specification. Why did you give that link?
> >
> >You earlier said that fields in TPM binding are derived from that
> >specification. For me this looks like total nonsense.
> 
> I am sorry Jarkko, if I didn't clearly communicated.
> I was trying to say that tpm device tree binding is new binding added within
> i2c node. And for that reason, I am now submitting a patch for its binding
> documentation.
> 
> And as ePAPR document explains about device trees and its properties, I just
> meant that fields defined for this new tpm node are also defined as per
> ePAPR spec.
> 
> Please let me know if I am still not answering your question, and sorry but
> if you can explain me again what exactly are you looking for.

1. Does TCG have a standard for this I2C binding in a DT like they have
   for ACPI?
2. Can I expect that the binding has the same fields with the same names
   in some other platform that POWER? For example, what if there was an
   ARM based platform. Would the same binding work there?

I'm looking for document or something where you got your information.
Right now your code is based on nothing from my point of view.

/Jarkko

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