Sonata simulator run through xmake

Instead of having a separate section to run examples in CI, this is now
done in xmake instead using the newly created sonata-simulator board
file.

.github/workflows/main.yml

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 01cf3c3..5036f0d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -20,8 +20,9 @@
             build-flags: --debug-loader=y --debug-scheduler=y --debug-allocator=y -m debug
           - build-type: release
             build-flags: --debug-loader=n --debug-scheduler=n --debug-allocator=n -m release --stack-usage-check-allocator=y --stack-usage-check-scheduler=y
-          - board: sonata-prerelease
+          - board: sonata-simulator
             build-type: release
+            build-flags: --debug-loader=n --debug-scheduler=n --debug-allocator=n -m release --stack-usage-check-allocator=y --stack-usage-check-scheduler=y --testing-model-output=y
             sonata: true
       fail-fast: false
     runs-on: ubuntu-latest
@@ -54,8 +55,6 @@
           xmake
         done
     - name: Run examples
-      # Currently xmake run tries to run Sonata on FPGA.
-      if: ${{ !matrix.sonata }}
       run: |
         set -e
         for example_dir in $PWD/examples/*/; do
@@ -63,16 +62,6 @@
           echo Running $example_dir
           xmake run
         done
-    - name: Sonata simulator examples
-      if: ${{ matrix.sonata }}
-      run: |
-        set -e
-        for example_dir in $PWD/examples/*/; do
-          directory=$(basename $example_dir)
-          elf_name=${directory##*.}
-          echo Running $elf_name
-          scripts/run-sonata-sim.sh $example_dir/build/cheriot/cheriot/${{ matrix.build-type }}/$elf_name scripts/model_output/sonata-simulator/examples/$elf_name.txt
-        done
     - name: Build benchmarks
       run: |
         set -e

sdk/xmake.lua

diff --git a/sdk/xmake.lua b/sdk/xmake.lua
index 0f26d6e..07a37c5 100644
--- a/sdk/xmake.lua
+++ b/sdk/xmake.lua
@@ -51,6 +51,17 @@
 stackCheckOption("allocator")
 stackCheckOption("scheduler")
 
+function testCheckOption(name)
+	option("testing-" .. name)
+		set_default(false)
+		set_description("Enable testing feature " .. name .. ". Do not enable this in builds that don't produce a UART log!")
+		set_showmenu(true)
+		set_category("Debugging")
+	option_end()
+end
+
+testCheckOption("model-output")
+
 -- Force -Oz irrespective of build config.  At -O0, we blow out our stack and
 -- require much stronger alignment.
 set_optimize("Oz")
@@ -284,7 +295,18 @@
 		local directory = path.directory(firmware)
 		firmware = path.filename(firmware)
 		local run = function(simulator)
-			os.execv(simulator, { firmware }, { curdir = directory })
+			local simargs = { firmware }
+			if get_config("testing-model-output") then
+				modeldir = path.join(scriptdir,
+				                     "..",
+				                     "scripts",
+				                     "model_output",
+				                     path.basename(target:values("board")),
+				                     "examples")
+				local modelout = path.join(modeldir, firmware .. ".txt")
+				simargs[#simargs+1] = modelout
+			end
+			os.execv(simulator, simargs, { curdir = directory })
 		end
 		-- Try executing the simulator from the sdk directory, if it's there.
 		local tools_directory = config.get("sdk")