remove SBT

CONTRIBUTING.md

@@ -77,6 +77,6 @@ Please see the Github documentation for [Pull Requests](https://help.github.com/
 
 Because Chisel and FIRRTL have mature release processes, Rocket Chip uses the published artifacts.
 
-To bump the published dependencies, bump the versions at the top of the SBT build file: [build.sbt](build.sbt).
+To bump the published dependencies, bump the versions at the top of the Mill build file: [build.sc](build.sc).
 Typically, the SBT dependency will only list a version for Chisel 3 which itself depends on FIRRTL.
 

Makefrag

@@ -25,7 +25,7 @@ EMPTY :=
 SPACE := $(EMPTY) $(EMPTY)
 COMMA := ,
 
-SBT ?= java -Xmx$(JVM_MEMORY) -Xss8M -jar $(base_dir)/sbt-launch.jar
+MILL ?= mill
 SHELL := /bin/bash
 
 FIRRTL_TRANSFORMS := \
@@ -37,16 +37,14 @@ JAVA ?= java -Xmx$(JVM_MEMORY) -Xss8M
 FIRRTL ?= $(JAVA) -cp $(ROCKET_CHIP_JAR) firrtl.stage.FirrtlMain
 GENERATOR ?= $(JAVA) -cp $(ROCKET_CHIP_JAR) $(PROJECT).Generator
 
-# Extracting this information from SBT would be more robust
-# api-config-chipsalliance does not use standard SBT src/main/scala, but has no resources
-scala_srcs := $(shell find $(base_dir) -name "*.scala" -o -name "*.sbt")
+scala_srcs := $(shell find $(base_dir) -name "*.scala" -o -name "*.sc")
 resource_dirs := $(shell find $(base_dir) -type d -path "*/src/main/resources")
 resources := $(foreach d,$(resource_dirs),$(shell find $(d) -type f))
 all_srcs := $(scala_srcs) $(resources)
 
-ROCKET_CHIP_JAR := $(base_dir)/rocketchip.jar
+ROCKET_CHIP_JAR := $(base_dir)/out/rocketchip/assembly.dest/out.jar
 $(ROCKET_CHIP_JAR): $(all_srcs)
-	cd $(base_dir) && $(SBT) assembly
+	cd $(base_dir) && $(MILL) rocketchip.assembly
 
 rc_resource_dir := $(base_dir)/src/main/resources
 csrc := $(rc_resource_dir)/csrc

README.md

@@ -94,20 +94,6 @@ To generate FPGA- or VLSI-synthesizable Verilog (output will be in `vsim/generat
     $ cd vsim
     $ make verilog
 
-To run the Scala tests (`sbt test`) or linter (`sbt scalafix`):
-
-    $ cd regression
-
-    # Scala tests
-    $ make scalatest SUITE=foo
-
-    # Scala linter, automatically modifying files to correct issues
-    $ make scalafix SUITE=foo
-
-    # Scala linter, only printing out issues
-    $ make scalafix-check SUITE=foo
-
-
 ### Keeping Your Repo Up-to-Date
 
 If you are trying to keep your repo up to date with this GitHub repo,
@@ -229,8 +215,6 @@ C sources for use with Verilator simulation.
 Documentation, tutorials, etc for specific parts of the codebase.
 * **emulator**
 Directory in which Verilator simulations are compiled and run.
-* **project**
-Directory used by SBT for Scala compilation and build.
 * **regression**
 Defines continuous integration and nightly regression suites.
 * **scripts**
@@ -696,10 +680,13 @@ Further information about GDB debugging is available [here](https://sourceware.o
 
 ## <a name="ide"></a> Building Rocket Chip with an IDE
 
-The Rocket Chip Scala build uses the standard Scala build tool SBT.
+The Rocket Chip Scala build uses [mill](https://github.com/com-lihaoyi/mill) as build tool.
 IDEs like [IntelliJ](https://www.jetbrains.com/idea/) and [VSCode](https://code.visualstudio.com/)
-are popular in the Scala community and work with Rocket Chip.
-To use one of these IDEs, there is one minor peculiarity of the Rocket Chip build that must be addressed.
+are popular in the Scala community and work with Rocket Chip. Use:
+```
+mill mill.bsp.BSP/install
+```
+to use one of these IDEs, there is one minor peculiarity of the Rocket Chip build that must be addressed.
 
 ## <a name="contributors"></a> Contributors
 

regression/Makefile

@@ -335,19 +335,3 @@ emulator-jtag-dtm-tests-64 : $(EMULATOR_JTAG_DTM_64_TEST_STAMPS)
 # Targets for JTAG DTM full-chain simulation
 vsim-jtag-dtm-regression: vsim-jtag-dtm-tests-32 vsim-jtag-dtm-tests-64
 emulator-jtag-dtm-regression: emulator-jtag-dtm-tests-32 emulator-jtag-dtm-tests-64
-
-# Target to run Scalatest regressions 'sbt test'
-.PHONY: scalatest
-scalatest: stamps/other-submodules.stamp $(all_srcs)
-	(cd $(base_dir) && $(SBT) $(SBT_OPTS) test)
-
-# Target to run Scalafix 'sbt scalafix'
-.PHONY: scalafix
-scalafix: stamps/other-submodules.stamp $(all_srcs)
-	(cd $(base_dir) && $(SBT) $(SBT_OPTS) scalafix)
-
-# Target to run Scalafix 'sbt scalafix --check', which will not actually modify
-# Scala files.
-.PHONY: scalafix-check
-scalafix-check: stamps/other-submodules.stamp $(all_srcs)
-	(cd $(base_dir) && $(SBT) $(SBT_OPTS) 'scalafix --check')

regression/run-test-bucket

@@ -70,12 +70,6 @@ case "${bucket_number}" in
   7)
     make emulator-ndebug -C regression SUITE=Miscellaneous JVM_MEMORY=3G
     ;;
-  8)
-    make scalatest -C regression SUITE=foo JVM_MEMORY=8G
-    ;;
-  9)
-    make scalafix-check -C regression SUITE=foo JVM_MEMORY=8G
-    ;;
 
   -h|--help)
     print_usage