diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 295e6db..9087512 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -10,4 +10,11 @@
 	  the basis of a variety of inter-process/inter-CPU communication
 	  protocols.
 
+config SANDBOX_MBOX
+	bool "Enable the sandbox mailbox test driver"
+	depends on DM_MAILBOX && SANDBOX
+	help
+	  Enable support for a test mailbox implementation, which simply echos
+	  back a modified version of any message that is sent.
+
 endmenu
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index a2d96a4..bbae4de 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -3,3 +3,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_DM_MAILBOX) += mailbox-uclass.o
+obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox.o
+obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox-test.o
diff --git a/drivers/mailbox/sandbox-mbox-test.c b/drivers/mailbox/sandbox-mbox-test.c
new file mode 100644
index 0000000..02d161a
--- /dev/null
+++ b/drivers/mailbox/sandbox-mbox-test.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <mailbox_client.h>
+#include <asm/io.h>
+
+struct sandbox_mbox_test {
+	struct mbox_chan chan;
+};
+
+int sandbox_mbox_test_get(struct udevice *dev)
+{
+	struct sandbox_mbox_test *sbmt = dev_get_priv(dev);
+
+	return mbox_get_by_name(dev, "test", &sbmt->chan);
+}
+
+int sandbox_mbox_test_send(struct udevice *dev, uint32_t msg)
+{
+	struct sandbox_mbox_test *sbmt = dev_get_priv(dev);
+
+	return mbox_send(&sbmt->chan, &msg);
+}
+
+int sandbox_mbox_test_recv(struct udevice *dev, uint32_t *msg)
+{
+	struct sandbox_mbox_test *sbmt = dev_get_priv(dev);
+
+	return mbox_recv(&sbmt->chan, msg, 100);
+}
+
+int sandbox_mbox_test_free(struct udevice *dev)
+{
+	struct sandbox_mbox_test *sbmt = dev_get_priv(dev);
+
+	return mbox_free(&sbmt->chan);
+}
+
+static const struct udevice_id sandbox_mbox_test_ids[] = {
+	{ .compatible = "sandbox,mbox-test" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_mbox_test) = {
+	.name = "sandbox_mbox_test",
+	.id = UCLASS_MISC,
+	.of_match = sandbox_mbox_test_ids,
+	.priv_auto_alloc_size = sizeof(struct sandbox_mbox_test),
+};
diff --git a/drivers/mailbox/sandbox-mbox.c b/drivers/mailbox/sandbox-mbox.c
new file mode 100644
index 0000000..1b7ac23
--- /dev/null
+++ b/drivers/mailbox/sandbox-mbox.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <mailbox_uclass.h>
+#include <asm/io.h>
+#include <asm/mbox.h>
+
+#define SANDBOX_MBOX_CHANNELS 2
+
+struct sandbox_mbox_chan {
+	bool rx_msg_valid;
+	uint32_t rx_msg;
+};
+
+struct sandbox_mbox {
+	struct sandbox_mbox_chan chans[SANDBOX_MBOX_CHANNELS];
+};
+
+static int sandbox_mbox_request(struct mbox_chan *chan)
+{
+	debug("%s(chan=%p)\n", __func__, chan);
+
+	if (chan->id >= SANDBOX_MBOX_CHANNELS)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int sandbox_mbox_free(struct mbox_chan *chan)
+{
+	debug("%s(chan=%p)\n", __func__, chan);
+
+	return 0;
+}
+
+static int sandbox_mbox_send(struct mbox_chan *chan, const void *data)
+{
+	struct sandbox_mbox *sbm = dev_get_priv(chan->dev);
+	const uint32_t *pmsg = data;
+
+	debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	sbm->chans[chan->id].rx_msg = *pmsg ^ SANDBOX_MBOX_PING_XOR;
+	sbm->chans[chan->id].rx_msg_valid = true;
+
+	return 0;
+}
+
+static int sandbox_mbox_recv(struct mbox_chan *chan, void *data)
+{
+	struct sandbox_mbox *sbm = dev_get_priv(chan->dev);
+	uint32_t *pmsg = data;
+
+	debug("%s(chan=%p, data=%p)\n", __func__, chan, data);
+
+	if (!sbm->chans[chan->id].rx_msg_valid)
+		return -ENODATA;
+
+	*pmsg = sbm->chans[chan->id].rx_msg;
+	sbm->chans[chan->id].rx_msg_valid = false;
+
+	return 0;
+}
+
+static int sandbox_mbox_bind(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	return 0;
+}
+
+static int sandbox_mbox_probe(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	return 0;
+}
+
+static const struct udevice_id sandbox_mbox_ids[] = {
+	{ .compatible = "sandbox,mbox" },
+	{ }
+};
+
+struct mbox_ops sandbox_mbox_mbox_ops = {
+	.request = sandbox_mbox_request,
+	.free = sandbox_mbox_free,
+	.send = sandbox_mbox_send,
+	.recv = sandbox_mbox_recv,
+};
+
+U_BOOT_DRIVER(sandbox_mbox) = {
+	.name = "sandbox_mbox",
+	.id = UCLASS_MAILBOX,
+	.of_match = sandbox_mbox_ids,
+	.bind = sandbox_mbox_bind,
+	.probe = sandbox_mbox_probe,
+	.priv_auto_alloc_size = sizeof(struct sandbox_mbox),
+	.ops = &sandbox_mbox_mbox_ops,
+};