diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index 8c764bb..64d2787 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -11,5 +11,6 @@ obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
 obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o xen_pt_msi.o
 obj-y += kvm/
 obj-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
+obj-y += testdev.o
 
 obj-y := $(addprefix ../,$(obj-y))
diff --git a/hw/testdev.c b/hw/testdev.c
new file mode 100644
index 0000000..44070f2
--- /dev/null
+++ b/hw/testdev.c
@@ -0,0 +1,131 @@
+#include <sys/mman.h>
+#include "hw.h"
+#include "qdev.h"
+#include "isa.h"
+
+struct testdev {
+    ISADevice dev;
+    MemoryRegion iomem;
+    CharDriverState *chr;
+};
+
+#define TYPE_TESTDEV "testdev"
+#define TESTDEV(obj) \
+     OBJECT_CHECK(struct testdev, (obj), TYPE_TESTDEV)
+
+static void test_device_irq_line(void *opaque, uint32_t addr, uint32_t data)
+{
+    struct testdev *dev = opaque;
+
+    qemu_set_irq(isa_get_irq(&dev->dev, addr - 0x2000), !!data);
+}
+
+static uint32 test_device_ioport_data;
+
+static void test_device_ioport_write(void *opaque, uint32_t addr, uint32_t data)
+{
+    test_device_ioport_data = data;
+}
+
+static uint32_t test_device_ioport_read(void *opaque, uint32_t addr)
+{
+    return test_device_ioport_data;
+}
+
+static void test_device_flush_page(void *opaque, uint32_t addr, uint32_t data)
+{
+    target_phys_addr_t len = 4096;
+    void *a = cpu_physical_memory_map(data & ~0xffful, &len, 0);
+
+    mprotect(a, 4096, PROT_NONE);
+    mprotect(a, 4096, PROT_READ|PROT_WRITE);
+    cpu_physical_memory_unmap(a, len, 0, 0);
+}
+
+static char *iomem_buf;
+
+static uint32_t test_iomem_readb(void *opaque, target_phys_addr_t addr)
+{
+    return iomem_buf[addr];
+}
+
+static uint32_t test_iomem_readw(void *opaque, target_phys_addr_t addr)
+{
+    return *(uint16_t*)(iomem_buf + addr);
+}
+
+static uint32_t test_iomem_readl(void *opaque, target_phys_addr_t addr)
+{
+    return *(uint32_t*)(iomem_buf + addr);
+}
+
+static void test_iomem_writeb(void *opaque, target_phys_addr_t addr, uint32_t val)
+{
+    iomem_buf[addr] = val;
+}
+
+static void test_iomem_writew(void *opaque, target_phys_addr_t addr, uint32_t val)
+{
+    *(uint16_t*)(iomem_buf + addr) = val;
+}
+
+static void test_iomem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
+{
+    *(uint32_t*)(iomem_buf + addr) = val;
+}
+
+static const MemoryRegionOps test_iomem_ops = {
+    .old_mmio = {
+        .read = { test_iomem_readb, test_iomem_readw, test_iomem_readl, },
+        .write = { test_iomem_writeb, test_iomem_writew, test_iomem_writel, },
+    },
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static int init_test_device(ISADevice *isa)
+{
+    struct testdev *dev = DO_UPCAST(struct testdev, dev, isa);
+
+    register_ioport_read(0xe0, 1, 1, test_device_ioport_read, dev);
+    register_ioport_write(0xe0, 1, 1, test_device_ioport_write, dev);
+    register_ioport_read(0xe0, 1, 2, test_device_ioport_read, dev);
+    register_ioport_write(0xe0, 1, 2, test_device_ioport_write, dev);
+    register_ioport_read(0xe0, 1, 4, test_device_ioport_read, dev);
+    register_ioport_write(0xe0, 1, 4, test_device_ioport_write, dev);
+    register_ioport_write(0xe4, 1, 4, test_device_flush_page, dev);
+    register_ioport_write(0x2000, 24, 1, test_device_irq_line, NULL);
+    iomem_buf = g_malloc0(0x10000);
+    memory_region_init_io(&dev->iomem, &test_iomem_ops, dev,
+                          "testdev", 0x10000);
+    memory_region_add_subregion(isa_address_space(&dev->dev), 0xff000000,
+                                                  &dev->iomem);
+    return 0;
+}
+
+static Property testdev_isa_properties[] = {
+    DEFINE_PROP_CHR("chardev", struct testdev, chr),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void testdev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    ISADeviceClass *k = ISA_DEVICE_CLASS(klass);
+
+    k->init = init_test_device;
+    dc->props = testdev_isa_properties;
+}
+
+static TypeInfo testdev_info = {
+    .name           = "testdev",
+    .parent         = TYPE_ISA_DEVICE,
+    .instance_size  = sizeof(struct testdev),
+    .class_init     = testdev_class_init,
+};
+
+static void testdev_register_types(void)
+{
+    type_register_static(&testdev_info);
+}
+
+type_init(testdev_register_types)
