Index: .cirrus.yml
===================================================================
--- /dev/null
+++ .cirrus.yml
@@ -0,0 +1,18 @@
+freebsd_instance:
+  image: freebsd-12-0-release-amd64
+  cpu: 8
+  memory: 24G
+
+env:
+  CIRRUS_CLONE_DEPTH: 1
+
+task:
+  timeout_in: 90m
+  install_script:
+  - pkg install -y qemu-devel
+  - fetch https://people.freebsd.org/~emaste/OVMF.fd
+  script:
+  - make -j$(sysctl -n hw.ncpu) WITHOUT_TOOLCHAIN=yes buildworld buildkernel
+  test_script:
+  - sh tools/ci/qemu-test.sh
+
Index: tools/ci/qemu-test.sh
===================================================================
--- /dev/null
+++ tools/ci/qemu-test.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+set -e
+
+# Root directory for minimal FreeBSD installation.
+ROOTDIR=$(pwd)/fat-root
+
+# Create minimal directory structure.
+rm -rf $ROOTDIR/rescue $ROOTDIR/efi/boot/BOOTx64.EFI
+for dir in dev efi/boot etc rescue; do
+	mkdir -p $ROOTDIR/$dir
+done
+
+# Install kernel, loader and rescue.
+make -DNO_ROOT DESTDIR=$ROOTDIR \
+    MODULES_OVERRIDE= \
+    WITHOUT_DEBUG_FILES=yes \
+    WITHOUT_KERNEL_SYMBOLS=yes \
+    installkernel
+for dir in stand rescue; do
+	make -DNO_ROOT DESTDIR=$ROOTDIR INSTALL="install -U" \
+	    CRUNCH_GENERATE_LINKS=no \
+	    WITHOUT_MAN= \
+	    WITHOUT_TOOLCHAIN= \
+	    -C $dir install
+done
+
+# Copy loader to standard EFI location, and rescue to required binaries.
+mv $ROOTDIR/boot/loader.efi $ROOTDIR/efi/boot/BOOTx64.EFI
+for bin in init sh shutdown; do
+	cp $ROOTDIR/rescue/rescue $ROOTDIR/rescue/$bin
+done
+rm -f $ROOTDIR/rescue/rescue
+
+# Configuration files.
+cat > $ROOTDIR/boot/loader.conf <<EOF
+vfs.root.mountfrom="msdosfs:/dev/ada0s1"
+autoboot_delay=-1
+boot_verbose=YES
+EOF
+cat > $ROOTDIR/etc/rc <<EOF
+#!/rescue/sh
+
+echo "Hello world."
+/rescue/shutdown -p now
+EOF
+
+timeout 300 \
+    qemu-system-x86_64 -m 256M -bios OVMF.fd \
+    -serial stdio -vga none -nographic -monitor none \
+    -snapshot -hda fat:$ROOTDIR 2>&1 | tee boot.log
+grep -q 'Hello world.' boot.log
+echo OK