Rename Config Mixins to Fragments (#451)

* [docs] rename config mixins -> fragments [ci skip]

* [docs] cleanup naming | link similar sections [ci skip]

* [boom] bump for mixin rename [ci skip]

* [docs] cleanup capitalization [ci skip]

* [docs] consistent config fragment naming [ci skip]

* [boom] bump boom for documentation changes [ci skip]

* [docs] update source comments [ci skip]

* [docs] fix last config fragment name [ci skip]

Co-Authored-By: alonamid <alonamid@eecs.berkeley.edu>

Co-authored-by: alonamid <alonamid@eecs.berkeley.edu>

docs/Customization/Heterogeneous-SoCs.rst

@@ -7,8 +7,8 @@ This discussion will focus on how you combine Rocket, BOOM and Hwacha in particu
 Creating a Rocket and BOOM System
 -------------------------------------------
 
-Instantiating an SoC with Rocket and BOOM cores is all done with the configuration system and two specific mixins.
-Both BOOM and Rocket have mixins labelled ``WithNBoomCores(X)`` and ``WithNBigCores(X)`` that automatically create ``X`` copies of the core/tile [1]_.
+Instantiating an SoC with Rocket and BOOM cores is all done with the configuration system and two specific config fragments.
+Both BOOM and Rocket have config fragments labelled ``WithNBoomCores(X)`` and ``WithNBigCores(X)`` that automatically create ``X`` copies of the core/tile [1]_.
 When used together you can create a heterogeneous system.
 
 The following example shows a dual core BOOM with a single core Rocket.
@@ -18,18 +18,18 @@ The following example shows a dual core BOOM with a single core Rocket.
     :start-after: DOC include start: DualBoomAndRocket
     :end-before: DOC include end: DualBoomAndRocket
 
-In this example, the ``WithNBoomCores`` and ``WithNBigCores`` mixins set up the default parameters for the multiple BOOM and Rocket cores, respectively.
-However, for BOOM, an extra mixin called ``WithLargeBooms`` is added to override the default parameters with a different set of more common default parameters.
-This mixin applies to all BOOM cores in the system and changes the parameters for each.
+In this example, the ``WithNBoomCores`` and ``WithNBigCores`` config fragments set up the default parameters for the multiple BOOM and Rocket cores, respectively.
+However, for BOOM, an extra config fragment called ``WithLargeBooms`` is added to override the default parameters with a different set of more common default parameters.
+This config fragment applies to all BOOM cores in the system and changes the parameters for each.
 
 Great! Now you have a heterogeneous setup with BOOMs and Rockets.
 The final thing you need to make this system work is to renumber the ``hartId``'s of the cores so that each core has a unique ``hartId`` (a ``hartId`` is the hardware thread id of the core).
-The ``WithRenumberHarts`` mixin solves this by assigning a unique ``hartId`` to all cores in the system (it can label the Rocket cores first or the BOOM cores first).
-The reason this is needed is because by default the ``WithN...Cores(X)`` mixin assumes that there are only BOOM or only Rocket cores in the system.
-Thus, without the ``WithRenumberHarts`` mixin, each set of cores is labeled starting from zero causing multiple cores to be assigned the same ``hartId``.
+The ``WithRenumberHarts`` config fragment solves this by assigning a unique ``hartId`` to all cores in the system (it can label the Rocket cores first or the BOOM cores first).
+The reason this is needed is because by default the ``WithN...Cores(X)`` config fragment assumes that there are only BOOM or only Rocket cores in the system.
+Thus, without the ``WithRenumberHarts`` config fragment, each set of cores is labeled starting from zero causing multiple cores to be assigned the same ``hartId``.
 
 Another alternative option to create a multi heterogeneous core system is to override the parameters yourself so you can specify the core parameters per core.
-The mixin to add to your system would look something like the following.
+The config fragment to add to your system would look something like the following.
 
 .. code-block:: scala
 
@@ -50,7 +50,7 @@ The mixin to add to your system would look something like the following.
       }
     })
 
-Then you could use this new mixin like the following.
+Then you could use this new config fragment like the following.
 
 .. code-block:: scala
 
@@ -83,7 +83,7 @@ All with the same Hwacha parameters.
 Assigning Accelerators to Specific Tiles with MultiRoCC
 -------------------------------------------------------
 
-Located in ``generators/chipyard/src/main/scala/ConfigMixins.scala`` is a mixin that provides support for adding RoCC accelerators to specific tiles in your SoC.
+Located in ``generators/chipyard/src/main/scala/ConfigFragments.scala`` is a config fragment that provides support for adding RoCC accelerators to specific tiles in your SoC.
 Named ``MultiRoCCKey``, this key allows you to attach RoCC accelerators based on the ``hartId`` of the tile.
 For example, using this allows you to create a 8 tile system with a RoCC accelerator on only a subset of the tiles.
 An example is shown below with two BOOM cores, and one Rocket tile with a RoCC accelerator (Hwacha) attached.
@@ -94,13 +94,13 @@ An example is shown below with two BOOM cores, and one Rocket tile with a RoCC a
     :end-before: DOC include end: DualBoomAndRocketOneHwacha
 
 In this example, the ``WithRenumberHarts`` relabels the ``hartId``'s of all the BOOM/Rocket cores.
-Then after that is applied to the parameters, the ``WithMultiRoCCHwacha`` mixin assigns a Hwacha accelerator to a particular ``hartId`` (in this case, the ``hartId`` of ``2`` corresponds to the Rocket core).
-Finally, the ``WithMultiRoCC`` mixin is called.
-This mixin sets the ``BuildRoCC`` key to use the ``MultiRoCCKey`` instead of the default.
+Then after that is applied to the parameters, the ``WithMultiRoCCHwacha`` config fragment assigns a Hwacha accelerator to a particular ``hartId`` (in this case, the ``hartId`` of ``2`` corresponds to the Rocket core).
+Finally, the ``WithMultiRoCC`` config fragment is called.
+This config fragment sets the ``BuildRoCC`` key to use the ``MultiRoCCKey`` instead of the default.
 This must be used after all the RoCC parameters are set because it needs to override the ``BuildRoCC`` parameter.
 If this is used earlier in the configuration sequence, then MultiRoCC does not work.
 
-This mixin can be changed to put more accelerators on more cores by changing the arguments to cover more ``hartId``'s (i.e. ``WithMultiRoCCHwacha(0,1,3,6,...)``).
+This config fragment can be changed to put more accelerators on more cores by changing the arguments to cover more ``hartId``'s (i.e. ``WithMultiRoCCHwacha(0,1,3,6,...)``).
 
 
 .. [1] Note, in this section "core" and "tile" are used interchangeably but there is subtle distinction between a "core" and "tile" ("tile" contains a "core", L1D/I$, PTW).