Move to a regression Makefile

In order to have the buildbot support various types of failures it needs
to run different commands.  Rather than modifying the regression script
to have a bunch of arguments I've just gone and made a makefile for
regressions instead.

This doesn't run torture right now because that's broken, but I'll add
support soon.

regression/Makefile

@@ -0,0 +1,51 @@
+# The default target
+regression: vsim-asm-tests vsim-bmark-tests torture
+
+ifeq ($(CONFIG),)
+$(error Set CONFIG to the configuration to build)
+endif
+
+# The top-level directory that contains rocket-chip
+TOP ?= ..
+
+# The directory that the tools get built into.
+RISCV ?= install
+
+# These are the named regression targets.  While it's expected you run them in
+# this order, since there's dependencies for everything it doesn't actually
+# matter.
+submodules: stamps/submodules.stamp
+tools: stamps/tools.stamp
+vsim: stamps/vsim.stamp
+vsim-asm-tests: stamps/vsim-asm-tests.stamp
+vsim-bmark-tests: stamps/vsim-bmark-tests.stamp
+torture: stamps/torture.stamp
+
+# Checks out all the rocket-chip submodules
+stamps/submodules.stamp:
+	mkdir -p $(dir $@)
+	git -C $(abspath $(TOP)) submodule update --init --recursive
+	touch $@
+
+# Builds the RISC-V toolchain
+stamps/tools.stamp: stamps/submodules.stamp
+	mkdir -p $(dir $@)
+	+cd $(abspath $(TOP))/riscv-tools; RISCV=$(abspath $(RISCV)) ./build.sh
+	touch $@
+
+# Builds the verilog RTL simulator
+stamps/vsim.stamp: stamps/submodules.stamp
+	mkdir -p $(dir $@)
+	$(MAKE) -C $(abspath $(TOP))/vsim CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV))
+	touch $@
+
+# Runs some tests using the verilog RTL simulator
+stamps/vsim-asm-tests.stamp: stamps/vsim.stamp stamps/tools.stamp stamps/submodules.stamp
+	mkdir -p $(dir $@)
+	$(MAKE) -C $(abspath $(TOP))/vsim CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) run-asm-tests
+	touch $@
+
+stamps/vsim-bmark-tests.stamp: stamps/vsim.stamp stamps/tools.stamp stamps/submodules.stamp
+	mkdir -p $(dir $@)
+	$(MAKE) -C $(abspath $(TOP))/vsim CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) run-bmark-tests
+	touch $@