Merge branch 'dev' of github.com:ucb-bar/chipyard into custom-core-doc

docs/Customization/Heterogeneous-SoCs.rst

@@ -10,7 +10,7 @@ Creating a Rocket and BOOM System
 -------------------------------------------
 
 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]_.
+Both BOOM and Rocket have config fragments labelled ``WithN{Small|Medium|Large|etc.}BoomCores(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.
@@ -20,52 +20,6 @@ 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`` 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`` 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 config fragment to add to your system would look something like the following.
-
-.. code-block:: scala
-
-    // create 6 cores (4 boom and 2 rocket)
-    class WithHeterCoresSetup extends Config((site, here, up) => {
-      case BoomTilesKey => {
-        val boomTile0 = BoomTileParams(...) // params for boom core 0
-        val boomTile1 = BoomTileParams(...) // params for boom core 1
-        val boomTile2 = BoomTileParams(...) // params for boom core 2
-        val boomTile3 = BoomTileParams(...) // params for boom core 3
-        Seq(boomTile0, boomTile1, boomTile2, boomTile3)
-      }
-
-      case RocketTilesKey => {
-        val rocketTile0 = RocketTileParams(...) // params for rocket core 0
-        val rocketTile1 = RocketTileParams(...) // params for rocket core 1
-        Seq(rocketTile0, rocketTile1)
-      }
-    })
-
-Then you could use this new config fragment like the following.
-
-.. code-block:: scala
-
-    class SixCoreConfig extends Config(
-      new WithTSI ++
-      new WithBootROM ++
-      new WithUART ++
-      new freechips.rocketchip.subsystem.WithNoMMIOPort ++
-      new freechips.rocketchip.subsystem.WithNoSlavePort ++
-      new WithHeterCoresSetup ++
-      new freechips.rocketchip.system.BaseConfig)
-
-Note, in this setup you need to specify the ``hartId`` of each core in the "TileParams", where each ``hartId`` is unique.
 
 Adding Hwachas
 -------------------------------------------
@@ -94,8 +48,7 @@ An example is shown below with two BOOM cores, and one Rocket tile with a RoCC a
     :start-after: DOC include start: DualBoomAndRocketOneHwacha
     :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`` config fragment assigns a Hwacha accelerator to a particular ``hartId`` (in this case, the ``hartId`` of ``2`` corresponds to the Rocket core).
+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.