[Patch V2] Build spec: add description for build with binary cache

[Yonghong Zhu <yonghong.zhu@intel.com>]

V2:
change the option name to --binary-destination and --binary-source.

fixes:https://bugzilla.tianocore.org/show_bug.cgi?id=689
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Kevin W Shaw <kevin.w.shaw@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
---
 .../82_auto-generation_process.md                    | 20 ++++++++++++++++++++
 README.md                                            |  1 +
 appendix_d_buildexe_command/d4_usage.md              | 19 +++++++++++++++----
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/8_pre-build_autogen_stage/82_auto-generation_process.md b/8_pre-build_autogen_stage/82_auto-generation_process.md
index 671a7d5..f2ddf32 100644
--- a/8_pre-build_autogen_stage/82_auto-generation_process.md
+++ b/8_pre-build_autogen_stage/82_auto-generation_process.md
@@ -1031,10 +1031,30 @@ maximum command line length.  The default value is 4096.
 **Note:** The following `FLAGS` options are included in the response file:
 `PP_FLAGS`, `CC_FLAGS`, `VFRPP_FLAGS`, `APP_FLAGS`, `ASLPP_FLAGS`, `ASLCC_FLAGS`,
 and `ASM_FLAGS`.
 **********
 
+#### 8.2.4.15 Build with Binary Cache
+
+**build** tool provides three new options for binary cache feature.
+--hash enables hash-based caching during build process. when --hash is enabled,
+build tool will base on the module hash value to do the incremental build, without
+--hash, build tool will base on the timestamp to do the incremental build. --hash
+option use md5 method to get every hash value, DSC/FDF, tools_def.txt, build_rule.txt
+and build command are calculated as global hash value, Package DEC and its include
+header files are calculated as package hash value, Module source files and its INF
+file are calculated as module hash value. Library hash value will combine the global
+hash value and its dependent package hash value. Driver hash value will combine the
+global hash value, its dependent package hash value and its linked library hash value.
+When --hash and --binary-destination are specified, build tool will copy the generated
+binary files for each module into the directory specified by binary-destination at the
+build phase. Binary-destination directory caches all the generated binary files.
+When --hash and --binary-source are specified, build tool will try to get the binary
+files from the binary source directory at the build phase. If the cached binary has
+the same hash value, it will be directly used. Otherwise, build tool will compile the
+source files and generate the binary files.
+
 ### 8.2.5 Post processing
 
 Once all files are parsed, the build tools will do following work for each EDK
 II module:
 
diff --git a/README.md b/README.md
index 52abb6a..ca59a35 100644
--- a/README.md
+++ b/README.md
@@ -215,5 +215,6 @@ Copyright (c) 2008-2017, Intel Corporation. All rights reserved.
 |            | [#523](https://bugzilla.tianocore.org/show_bug.cgi?id=523) Build spec: add EBNF for the --pcd syntax in the Section D.4                                                                                                                                                                                                                                             |               |
 |            | [#517](https://bugzilla.tianocore.org/show_bug.cgi?id=517) Build spec: chapter 5.2.2 Guided Tools add description for Pkcs7Sign tool and BrotliCompress tool                                                                                                                                                                                                        |               |
 |            | [#481](https://bugzilla.tianocore.org/show_bug.cgi?id=481) Build Spec: add clarification for not used Pcd that build tool will not do additional checks on its value                                                                                                                                                                                                |               |
 |            | [#518](https://bugzilla.tianocore.org/show_bug.cgi?id=518) Build Spec: Update Precedence of PCD Values                                                                                                                                                                                                                                                              |               |
 |            | [#669](https://bugzilla.tianocore.org/show_bug.cgi?id=669) Build Spec: Add multi-arg support to PREBUILD/POSTBUILD                                                                                                                                                                                                                                                  |               |
+|            | [#689](https://bugzilla.tianocore.org/show_bug.cgi?id=689) Build spec: add description for build with binary cache                                                                                                                                                                                                                                                  |               |
diff --git a/appendix_d_buildexe_command/d4_usage.md b/appendix_d_buildexe_command/d4_usage.md
index b71f2d0..c901266 100644
--- a/appendix_d_buildexe_command/d4_usage.md
+++ b/appendix_d_buildexe_command/d4_usage.md
@@ -32,19 +32,20 @@
 ## D.4 Usage
 
 ```ini
 Usage: build.exe [options]
 [all|fds|genc|genmake|clean|cleanall|cleanlib|modules|libraries|run]
-Copyright (c) 2007 - 2014, Intel Corporation All rights reserved.
+Copyright (c) 2007 - 2017, Intel Corporation All rights reserved.
 
 Options:
   --version             show program's version number and exit
   -h, --help            show this help message and exit
   -a TARGETARCH, --arch=TARGETARCH
-                        ARCHS is one of list: IA32, X64, IPF, ARM, or EBC,
-                        which overrides target.txt's TARGET_ARCH definition.
-                        To specify more archs, please repeat this option.
+                        ARCHS is one of list: IA32, X64, IPF, ARM, AARCH64 or
+                        EBC, which overrides target.txt's TARGET_ARCH
+                        definition. To specify more archs, please repeat this
+                        option.
   -p PLATFORMFILE, --platform=PLATFORMFILE
                         Build the platform specified by the DSC file name
                         argument, overriding target.txt's ACTIVE_PLATFORM
                         definition.
   -m MODULEFILE, --module=MODULEFILE
@@ -112,10 +113,20 @@ Options:
   -N, --no-cache        Disable build cache mechanism
   --conf=CONFDIRECTORY  Specify the customized Conf directory.
   --check-usage         Check usage content of entries listed in INF file.
   --ignore-sources      Focus to a binary build and ignore all source files
   --pcd=OPTIONPCD       Set PCD value by command line. Format: "PcdName=Value"
+  -l COMMANDLENGTH, --cmd-len=COMMANDLENGTH
+                        Specify the maximum line length of build command.
+                        Default is 4096.
+  --hash                Enable hash-based caching during build process.
+  --binary-destination=BINCACHEDEST
+                        Generate a cache of binary files in the specified
+                        directory.
+  --binary-source=BINCACHESOURCE
+                        Consume a cache of binary files from the specified
+                        directory.
 ```
 
 ### D.4.1 Debug Levels
 
 The numeric debug levels are defined as integer values 0-9.
-- 
2.6.1.windows.1