CodeLayout.md

Code Layout

• Code Layout
  • Introduction
  • Form Follows Function
  • Tpm Reference Code (TPMCmd folder)
  • Tpm Core Library (TPMCmd/tpm folder)
  • Tpm Core Library Includes (TPMCmd/tpm/include folder)
  • Tpm Core Library CryptoLibs (TPMCmd/tpm/cryptolibs folder)
  • Platform Library (TPMCmd/Platform folder)

Introduction

The code layout of the repository consists of the several top-level folders. Portions of the repository are provided for example or historical reasons and are unmaintained. Pull Requests to update or fix non-maintained code are considered subject to CONTRIBUTING.md

Folder	Description	Maintained?
docs	These documents	YES
external	WolfSSL submodule (currently not building correctly)	NO
Samples	Misc Sample TPM applications	NO
scripts	miscellaneous scripts	YES
TPMCmd	TPM Reference Code and Library	YES

Form Follows Function

The physical directory layout of the reference code is based on achieving two simultaneous goals:

1. to build the TCG Reference Code, Simulator, and Platform library.
2. to allow library consumers to consume only library components while injecting changes at multiple customization points. Items designated Replaceable can be replaced with user components as described in other documents to construct a different TPM application.

In order to achieve these goals in a way that can be consumed by the greatest variety of downstream build systems, the Core Library CMake build system outputs an "install tree" consisting of headers and libraries that can be consumed by various downstream build systems as well as a set of CMake Packages that can be consumed via CMake find_package if the downstream system uses CMake.

The folder layout of the TPMCmd source tree reflects these CMake build decisions as described in CMake Build.

The remainder of this document outlines what is in the top-level folders of the repository.

Tpm Reference Code (TPMCmd folder)

The structure of TPMCmd is:

Folder	Description	Replaceable?
Platform	The Reference example platform library	YES
Simulator	The Reference test application	YES
tpm	The TPM Core Library	NO
TpmConfiguration	The TPM Configuration files for Simulator	YES

Tpm Core Library (TPMCmd/tpm folder)

The structure of TPMCmd/tpm:

Folder	Description	Maintained?	Replaceable?
cmake	CMake build scripts and helpers	YES	NO
cryptolibs	Core and Sample crypto libraries (see below)	VARIES	VARIES
include	Various TPM Header libraries (see below)	YES	NO
src	The TPM Core Library	YES	NO

Tpm Core Library Includes (TPMCmd/tpm/include folder)

The structure of TPMCmd/tpm/include:

Folder	Description	Maintained?	Replaceable?
platform_interface	CMake build scripts	YES	NO
private	Core and Sample crypto libraries (see below)	YES	NO
public	Various TPM Header libraries (see below)	YES	NO

Tpm Core Library CryptoLibs (TPMCmd/tpm/cryptolibs folder)

The cryptolibs folder contains both maintained code and legacy code that is kept for illustration but is not currently maintained. In particular wolf crypto implementations do not correctly build at present.

The structure of TPMCmd/tpm/cryptolibs:

Folder	Description	Maintained?	Replaceable?	Requires TpmBigNum?
common	Core TPM Crypto Interface definitions	YES	NO	N/A
Ossl	OpenSSL Crypto Interface layer	YES	YES	YES
TpmBigNum	The TPM "Big Number" Math Library	YES	YES	N/A
wolf	WolfSSL Crypto Interface layer	NO	YES	YES

More details about the Crypto design and customization can be found under Architecture:

Platform Library (TPMCmd/Platform folder)

Folder	Description	Maintained?	Replaceable?
include	Tpm_PlatformLib headers	YES	YES
src	Tpm_PlatformLib source	YES	YES