Consolidate on XPack GCC and move to Github Actions (#99)

* Use Github Actions instead of Azure

* Use riscv-none-elf from Xpack project.

.github/workflows/ci.yml

@@ -0,0 +1,38 @@
+name: Continuous Integration
+
+on: [push, pull_request]
+
+jobs:
+  ci:
+    name: ci
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          submodules: recursive
+      - name: Setup Scala
+        uses: olafurpg/setup-scala@v10
+        with:
+          java-version: [email protected]
+      - name: Cache Scala
+        uses: coursier/cache-action@v5
+      - name: Install dependencies
+        run: |
+          sudo apt install verilator cmake -y
+          wget -q --show-progress https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v14.2.0-2/xpack-riscv-none-elf-gcc-14.2.0-2-linux-x64.tar.gz -O gcc.tar.gz
+          tar xvf gcc.tar.gz --directory=/opt
+          echo "RISCV_TOOL_PATH_PREFIX=/opt/xpack-riscv-none-elf-gcc-14.2.0-2" >> $GITHUB_ENV
+      - name: Run Chisel unit tests
+        run: sbt 'test'
+      - name: Build emulator and SDK
+        run: source env.bash && cmake -Bbuild && cd build && make all install
+      - name: Run C tests
+        run: |
+          source env.bash
+          cd sdk && cmake -B build && cd build && make && ctest
+      - name: Run multithreaded C tests
+        run: |
+          source env.bash
+          # Run multiple tests with script
+          ./scripts/run_multiple_tests.sh

README.md

@@ -11,7 +11,16 @@ For more information on the processor architecture:
 # Tools and installation
 
 ## RISC-V Compiler
-We use the Newlib installation of the [rv32i-4.0.0](https://github.com/stnolting/riscv-gcc-prebuilt). Download and extract it to a convenient location on the PATH. Also set the `RISCV_TOOL_PATH_PREFIX` environment variable to the location of `bin/`. E.g., if you extracted the compiler to `/opt/riscv`, then `export RISCV_TOOL_PATH_PREFIX=/opt/riscv` is needed. We recommend adding this to your `~/.bashrc`.
+We use the `riscv-none-elf-gcc` compiler provided by xPack project. To install this toolchain to `/opt/xpack-riscv-none-elf-gcc-14.2.0-2` perform the following steps.
+
+```
+  wget -q --show-progress https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v14.2.0-2/xpack-riscv-none-elf-gcc-14.2.0-2-linux-x64.tar.gz -O gcc.tar.gz
+  tar xvf gcc.tar.gz --directory=/opt
+```
+
+Then add `export RISCV_TOOL_PATH_PREFIX=/opt/xpack-riscv-none-elf-gcc-14.2.0-2` to your `~/.bashrc`
+
+There are also versions for macOS and Windows. Refer to the [documentation](https://xpack-dev-tools.github.io/riscv-none-elf-gcc-xpack/) for more information.
 
 ## Verilator
 We use the `verilator` toolchain for running emulations of the core. Install it and check that the version is greater than 4.038.

sdk/cmake/riscv-toolchain.cmake

@@ -20,7 +20,7 @@ set(RISCV_HOST_TAG linux)
 set(RISCV_TOOL_PATH $ENV{RISCV_TOOL_PATH_PREFIX} CACHE PATH "RISC-V tool path" FORCE)
 
 set(RISCV_TOOLCHAIN_ROOT "${RISCV_TOOL_PATH}/bin" CACHE PATH "RISC-V compiler path")
-set(RISCV_TOOLCHAIN_PREFIX "riscv64-unknown-elf-" CACHE STRING "RISC-V toolchain prefix")
+set(RISCV_TOOLCHAIN_PREFIX "riscv-none-elf-" CACHE STRING "RISC-V toolchain prefix")
 set(CMAKE_FIND_ROOT_PATH ${RISCV_TOOLCHAIN_ROOT})
 list(APPEND CMAKE_PREFIX_PATH "${RISCV_TOOLCHAIN_ROOT}")