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[opentitantool] Advanced TPM primitives in transport #25259

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[opentitantool] Advanced TPM primitives in transport #25259

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Commits on Nov 19, 2024

  1. [opentitantool] Enhance SPI and I2C traits 

    Add a `set_pins()` method to the I2C trait.  This allows instructing the
debugger to set up its pinmux, if it has such support, in the same way
as the existing method on the SPI trait.

Also, add a new pin to both SPI and I2C called `gsc_ready`.  This one
will not be used by normal I2C or SPI communication, but the debugger
can be instructed to wait for a falling edge on that pin, before
continuing the transaction, typically the sequence given to
`run_transcation()` would look somewhat like `[Write(...), GscReady,
Read(...)]` which would have the effect that the debugger would send a
number of bytes, and then wait for falling edge before resuming clocking
to retrieve the response.  This is useful when communicating with Google
Security Chips.

Finally, the SPI trait is enhanced with a `TpmPoll` instruction, which
is to be used like `[Write(...), TpmPoll, Read/Write(...)]` when
communicating with standards-compliant TPM devices.  It has the effect
that the debugger will first send the request (must be 4 bytes), then it
will repeatedly poll by reading a single byte at a time, until the
device responds with 0x01, before the debugger reads or writes the main
data part.

Signed-off-by: Jes B. Klinke <[email protected]>

Change-Id: Ied56bac014a6d5bfe501a6bd3f34c7b21b69265d
    @jesultra
    jesultra committed Nov 19, 2024
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  2. [opentitantool] HyperDebug support for advanced TPM primitives 

    Add support in the HyperDebug transport driver for `TpmPoll` and
`GscReady`.

Signed-off-by: Jes B. Klinke <[email protected]>

Change-Id: I154229794bcb88cc7845329c03621eec5c4da4a5
    @jesultra
    jesultra committed Nov 19, 2024
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  3. [opentitantool] Make TPM driver take advantage of new primitives 

    Adapt TPM driver layer to use advanced transport features, if available.

This change speeds up TPM communication between 2x and 4x when
HyperDebug is used to communicate with GSC chips.

(This CL also removes unused code which tried to deal with SPI TPM
transactions on debuggers which do not support bidirectional SPI
transfers.)

Signed-off-by: Jes B. Klinke <[email protected]>

Change-Id: I16c56d367478c1394825b1be56a3622452af207a
    @jesultra
    jesultra committed Nov 19, 2024
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