diff --git a/plat/st/common/include/usb_dfu.h b/plat/st/common/include/usb_dfu.h
new file mode 100644
index 0000000..f7d4245
--- /dev/null
+++ b/plat/st/common/include/usb_dfu.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2021, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef USB_DFU_H
+#define USB_DFU_H
+
+#include <stdint.h>
+
+#include <drivers/usb_device.h>
+
+#define DFU_DESCRIPTOR_TYPE		0x21U
+
+/* Max DFU Packet Size = 1024 bytes */
+#define USBD_DFU_XFER_SIZE		1024U
+
+#define TRANSFER_SIZE_BYTES(size) \
+	((uint8_t)((size) & 0xFF)), /* XFERSIZEB0 */\
+	((uint8_t)((size) >> 8))    /* XFERSIZEB1 */
+
+/*
+ * helper for descriptor of DFU interface 0 Alternate setting n
+ * with iInterface = index of string descriptor, assumed Nth user string
+ */
+#define USBD_DFU_IF_DESC(n)	0x09U, /* Interface Descriptor size */\
+				USB_DESC_TYPE_INTERFACE, /* descriptor type */\
+				0x00U, /* Number of Interface */\
+				(n), /* Alternate setting */\
+				0x00U, /* bNumEndpoints*/\
+				0xFEU, /* Application Specific Class Code */\
+				0x01U, /* Device Firmware Upgrade Code */\
+				0x02U, /* DFU mode protocol */ \
+				USBD_IDX_USER0_STR + (n) /* iInterface */
+
+/* DFU1.1 Standard */
+#define USB_DFU_VERSION			0x0110U
+#define USB_DFU_ITF_SIZ			9U
+#define USB_DFU_DESC_SIZ(itf)		(USB_DFU_ITF_SIZ * ((itf) + 2U))
+
+/*
+ * bmAttribute value for DFU:
+ * bitCanDnload = 1(bit 0)
+ * bitCanUpload = 1(bit 1)
+ * bitManifestationTolerant = 1 (bit 2)
+ * bitWillDetach = 1(bit 3)
+ * Reserved (bit4-6)
+ * bitAcceleratedST = 0(bit 7)
+ */
+#define DFU_BM_ATTRIBUTE		0x0FU
+
+#define DFU_STATUS_SIZE			6U
+
+/* Callback for media access */
+struct usb_dfu_media {
+	int (*upload)(uint8_t alt, uintptr_t *buffer, uint32_t *len,
+		      void *user_data);
+	int (*download)(uint8_t alt, uintptr_t *buffer, uint32_t *len,
+			void *user_data);
+	int (*manifestation)(uint8_t alt, void *user_data);
+};
+
+/* Internal DFU handle */
+struct usb_dfu_handle {
+	uint8_t status[DFU_STATUS_SIZE];
+	uint8_t dev_state;
+	uint8_t dev_status;
+	uint8_t alt_setting;
+	const struct usb_dfu_media *callback;
+};
+
+void usb_dfu_register(struct usb_handle *pdev, struct usb_dfu_handle *phandle);
+
+int usb_dfu_loop(struct usb_handle *pdev, const struct usb_dfu_media *pmedia);
+
+/* Function provided by plat */
+struct usb_handle *usb_dfu_plat_init(void);
+
+#endif /* USB_DFU_H */
diff --git a/plat/st/common/usb_dfu.c b/plat/st/common/usb_dfu.c
new file mode 100644
index 0000000..8bb0994
--- /dev/null
+++ b/plat/st/common/usb_dfu.c
@@ -0,0 +1,538 @@
+/*
+ * Copyright (c) 2021, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+#include <string.h>
+
+#include <common/debug.h>
+
+#include <platform_def.h>
+#include <usb_dfu.h>
+
+/* Device states as defined in DFU spec */
+#define STATE_APP_IDLE			0
+#define STATE_APP_DETACH		1
+#define STATE_DFU_IDLE			2
+#define STATE_DFU_DNLOAD_SYNC		3
+#define STATE_DFU_DNLOAD_BUSY		4
+#define STATE_DFU_DNLOAD_IDLE		5
+#define STATE_DFU_MANIFEST_SYNC		6
+#define STATE_DFU_MANIFEST		7
+#define STATE_DFU_MANIFEST_WAIT_RESET	8
+#define STATE_DFU_UPLOAD_IDLE		9
+#define STATE_DFU_ERROR			10
+
+/* DFU errors */
+#define DFU_ERROR_NONE			0x00
+#define DFU_ERROR_TARGET		0x01
+#define DFU_ERROR_FILE			0x02
+#define DFU_ERROR_WRITE			0x03
+#define DFU_ERROR_ERASE			0x04
+#define DFU_ERROR_CHECK_ERASED		0x05
+#define DFU_ERROR_PROG			0x06
+#define DFU_ERROR_VERIFY		0x07
+#define DFU_ERROR_ADDRESS		0x08
+#define DFU_ERROR_NOTDONE		0x09
+#define DFU_ERROR_FIRMWARE		0x0A
+#define DFU_ERROR_VENDOR		0x0B
+#define DFU_ERROR_USB			0x0C
+#define DFU_ERROR_POR			0x0D
+#define DFU_ERROR_UNKNOWN		0x0E
+#define DFU_ERROR_STALLEDPKT		0x0F
+
+/* DFU request */
+#define DFU_DETACH			0
+#define DFU_DNLOAD			1
+#define DFU_UPLOAD			2
+#define DFU_GETSTATUS			3
+#define DFU_CLRSTATUS			4
+#define DFU_GETSTATE			5
+#define DFU_ABORT			6
+
+static bool usb_dfu_detach_req;
+
+/*
+ * usb_dfu_init
+ *         Initialize the DFU interface
+ * pdev: device instance
+ * cfgidx: Configuration index
+ * return: status
+ */
+static uint8_t usb_dfu_init(struct usb_handle *pdev, uint8_t cfgidx)
+{
+	(void)pdev;
+	(void)cfgidx;
+
+	/* Nothing to do in this stage */
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_de_init
+ *         De-Initialize the DFU layer
+ * pdev: device instance
+ * cfgidx: Configuration index
+ * return: status
+ */
+static uint8_t usb_dfu_de_init(struct usb_handle *pdev, uint8_t cfgidx)
+{
+	(void)pdev;
+	(void)cfgidx;
+
+	/* Nothing to do in this stage */
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_data_in
+ *         handle data IN Stage
+ * pdev: device instance
+ * epnum: endpoint index
+ * return: status
+ */
+static uint8_t usb_dfu_data_in(struct usb_handle *pdev, uint8_t epnum)
+{
+	(void)pdev;
+	(void)epnum;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_ep0_rx_ready
+ *         handle EP0 Rx Ready event
+ * pdev: device
+ * return: status
+ */
+static uint8_t usb_dfu_ep0_rx_ready(struct usb_handle *pdev)
+{
+	(void)pdev;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_ep0_tx_ready
+ *         handle EP0 TRx Ready event
+ * pdev: device instance
+ * return: status
+ */
+static uint8_t usb_dfu_ep0_tx_ready(struct usb_handle *pdev)
+{
+	(void)pdev;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_sof
+ *         handle SOF event
+ * pdev: device instance
+ * return: status
+ */
+static uint8_t usb_dfu_sof(struct usb_handle *pdev)
+{
+	(void)pdev;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_iso_in_incomplete
+ *         handle data ISO IN Incomplete event
+ * pdev: device instance
+ * epnum: endpoint index
+ * return: status
+ */
+static uint8_t usb_dfu_iso_in_incomplete(struct usb_handle *pdev, uint8_t epnum)
+{
+	(void)pdev;
+	(void)epnum;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_iso_out_incomplete
+ *         handle data ISO OUT Incomplete event
+ * pdev: device instance
+ * epnum: endpoint index
+ * return: status
+ */
+static uint8_t usb_dfu_iso_out_incomplete(struct usb_handle *pdev,
+					  uint8_t epnum)
+{
+	(void)pdev;
+	(void)epnum;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_data_out
+ *         handle data OUT Stage
+ * pdev: device instance
+ * epnum: endpoint index
+ * return: status
+ */
+static uint8_t usb_dfu_data_out(struct usb_handle *pdev, uint8_t epnum)
+{
+	(void)pdev;
+	(void)epnum;
+
+	return USBD_OK;
+}
+
+/*
+ * usb_dfu_detach
+ *         Handles the DFU DETACH request.
+ * pdev: device instance
+ * req: pointer to the request structure.
+ */
+static void usb_dfu_detach(struct usb_handle *pdev, struct usb_setup_req *req)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	INFO("Receive DFU Detach\n");
+
+	if ((hdfu->dev_state == STATE_DFU_IDLE) ||
+	    (hdfu->dev_state == STATE_DFU_DNLOAD_SYNC) ||
+	    (hdfu->dev_state == STATE_DFU_DNLOAD_IDLE) ||
+	    (hdfu->dev_state == STATE_DFU_MANIFEST_SYNC) ||
+	    (hdfu->dev_state == STATE_DFU_UPLOAD_IDLE)) {
+		/* Update the state machine */
+		hdfu->dev_state = STATE_DFU_IDLE;
+		hdfu->dev_status = DFU_ERROR_NONE;
+	}
+
+	usb_dfu_detach_req = true;
+}
+
+/*
+ * usb_dfu_download
+ *         Handles the DFU DNLOAD request.
+ * pdev: device instance
+ * req: pointer to the request structure
+ */
+static void usb_dfu_download(struct usb_handle *pdev, struct usb_setup_req *req)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+	uintptr_t data_ptr;
+	uint32_t length;
+	int ret;
+
+	/* Data setup request */
+	if (req->length > 0) {
+		/* Unsupported state */
+		if ((hdfu->dev_state != STATE_DFU_IDLE) &&
+		    (hdfu->dev_state != STATE_DFU_DNLOAD_IDLE)) {
+			/* Call the error management function (command will be nacked) */
+			usb_core_ctl_error(pdev);
+			return;
+		}
+
+		/* Get the data address */
+		length = req->length;
+		ret = hdfu->callback->download(hdfu->alt_setting, &data_ptr,
+					       &length, pdev->user_data);
+		if (ret == 0U) {
+			/* Update the state machine */
+			hdfu->dev_state = STATE_DFU_DNLOAD_SYNC;
+			/* Start the transfer */
+			usb_core_receive_ep0(pdev, (uint8_t *)data_ptr, length);
+		} else {
+			usb_core_ctl_error(pdev);
+		}
+	} else {
+		/* End of DNLOAD operation*/
+		if (hdfu->dev_state != STATE_DFU_DNLOAD_IDLE) {
+			/* Call the error management function (command will be nacked) */
+			usb_core_ctl_error(pdev);
+			return;
+		}
+		/* End of DNLOAD operation*/
+		hdfu->dev_state = STATE_DFU_MANIFEST_SYNC;
+		ret = hdfu->callback->manifestation(hdfu->alt_setting, pdev->user_data);
+		if (ret == 0U) {
+			hdfu->dev_state = STATE_DFU_MANIFEST_SYNC;
+		} else {
+			usb_core_ctl_error(pdev);
+		}
+	}
+}
+
+/*
+ * usb_dfu_upload
+ *         Handles the DFU UPLOAD request.
+ * pdev: instance
+ * req: pointer to the request structure
+ */
+static void usb_dfu_upload(struct usb_handle *pdev, struct usb_setup_req *req)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+	uintptr_t data_ptr;
+	uint32_t length;
+	int ret;
+
+	/* Data setup request */
+	if (req->length == 0) {
+		/* No Data setup request */
+		hdfu->dev_state = STATE_DFU_IDLE;
+		return;
+	}
+
+	/* Unsupported state */
+	if ((hdfu->dev_state != STATE_DFU_IDLE) && (hdfu->dev_state != STATE_DFU_UPLOAD_IDLE)) {
+		ERROR("UPLOAD : Unsupported State\n");
+		/* Call the error management function (command will be nacked) */
+		usb_core_ctl_error(pdev);
+		return;
+	}
+
+	/* Update the data address */
+	length = req->length;
+	ret = hdfu->callback->upload(hdfu->alt_setting, &data_ptr, &length, pdev->user_data);
+	if (ret == 0U) {
+		/* Short frame */
+		hdfu->dev_state = (req->length > length) ? STATE_DFU_IDLE : STATE_DFU_UPLOAD_IDLE;
+
+		/* Start the transfer */
+		usb_core_transmit_ep0(pdev, (uint8_t *)data_ptr, length);
+	} else {
+		ERROR("UPLOAD : bad block %i on alt %i\n", req->value, req->index);
+		hdfu->dev_state = STATE_DFU_ERROR;
+		hdfu->dev_status = DFU_ERROR_STALLEDPKT;
+
+		/* Call the error management function (command will be nacked) */
+		usb_core_ctl_error(pdev);
+	}
+}
+
+/*
+ * usb_dfu_get_status
+ *         Handles the DFU GETSTATUS request.
+ * pdev: instance
+ */
+static void usb_dfu_get_status(struct usb_handle *pdev)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	hdfu->status[0] = hdfu->dev_status;	/* bStatus */
+	hdfu->status[1] = 0;			/* bwPollTimeout[3] */
+	hdfu->status[2] = 0;
+	hdfu->status[3] = 0;
+	hdfu->status[4] = hdfu->dev_state;	/* bState */
+	hdfu->status[5] = 0;			/* iString */
+
+	/* next step */
+	switch (hdfu->dev_state) {
+	case STATE_DFU_DNLOAD_SYNC:
+		hdfu->dev_state = STATE_DFU_DNLOAD_IDLE;
+		break;
+	case STATE_DFU_MANIFEST_SYNC:
+		/* the device is 'ManifestationTolerant' */
+		hdfu->status[4] = STATE_DFU_MANIFEST;
+		hdfu->status[1] = 1U; /* bwPollTimeout = 1ms */
+		hdfu->dev_state = STATE_DFU_IDLE;
+		break;
+
+	default:
+		break;
+	}
+
+	/* Start the transfer */
+	usb_core_transmit_ep0(pdev, (uint8_t *)&hdfu->status[0], sizeof(hdfu->status));
+}
+
+/*
+ * usb_dfu_clear_status
+ *         Handles the DFU CLRSTATUS request.
+ * pdev: device instance
+ */
+static void usb_dfu_clear_status(struct usb_handle *pdev)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	if (hdfu->dev_state == STATE_DFU_ERROR) {
+		hdfu->dev_state = STATE_DFU_IDLE;
+		hdfu->dev_status = DFU_ERROR_NONE;
+	} else {
+		/* State Error */
+		hdfu->dev_state = STATE_DFU_ERROR;
+		hdfu->dev_status = DFU_ERROR_UNKNOWN;
+	}
+}
+
+/*
+ * usb_dfu_get_state
+ *         Handles the DFU GETSTATE request.
+ * pdev: device instance
+ */
+static void usb_dfu_get_state(struct usb_handle *pdev)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	/* Return the current state of the DFU interface */
+	usb_core_transmit_ep0(pdev, &hdfu->dev_state, 1);
+}
+
+/*
+ * usb_dfu_abort
+ *         Handles the DFU ABORT request.
+ * pdev: device instance
+ */
+static void usb_dfu_abort(struct usb_handle *pdev)
+{
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	if ((hdfu->dev_state == STATE_DFU_IDLE) ||
+	    (hdfu->dev_state == STATE_DFU_DNLOAD_SYNC) ||
+	    (hdfu->dev_state == STATE_DFU_DNLOAD_IDLE) ||
+	    (hdfu->dev_state == STATE_DFU_MANIFEST_SYNC) ||
+	    (hdfu->dev_state == STATE_DFU_UPLOAD_IDLE)) {
+		hdfu->dev_state = STATE_DFU_IDLE;
+		hdfu->dev_status = DFU_ERROR_NONE;
+	}
+}
+
+/*
+ * usb_dfu_setup
+ *         Handle the DFU specific requests
+ * pdev: instance
+ * req: usb requests
+ * return: status
+ */
+static uint8_t usb_dfu_setup(struct usb_handle *pdev, struct usb_setup_req *req)
+{
+	uint8_t *pbuf = NULL;
+	uint16_t len = 0U;
+	uint8_t ret = USBD_OK;
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	switch (req->bm_request & USB_REQ_TYPE_MASK) {
+	case USB_REQ_TYPE_CLASS:
+		switch (req->b_request) {
+		case DFU_DNLOAD:
+			usb_dfu_download(pdev, req);
+			break;
+
+		case DFU_UPLOAD:
+			usb_dfu_upload(pdev, req);
+			break;
+
+		case DFU_GETSTATUS:
+			usb_dfu_get_status(pdev);
+			break;
+
+		case DFU_CLRSTATUS:
+			usb_dfu_clear_status(pdev);
+			break;
+
+		case DFU_GETSTATE:
+			usb_dfu_get_state(pdev);
+			break;
+
+		case DFU_ABORT:
+			usb_dfu_abort(pdev);
+			break;
+
+		case DFU_DETACH:
+			usb_dfu_detach(pdev, req);
+			break;
+
+		default:
+			ERROR("unknown request %x on alternate %i\n",
+			      req->b_request, hdfu->alt_setting);
+			usb_core_ctl_error(pdev);
+			ret = USBD_FAIL;
+			break;
+		}
+		break;
+	case USB_REQ_TYPE_STANDARD:
+		switch (req->b_request) {
+		case USB_REQ_GET_DESCRIPTOR:
+			if (HIBYTE(req->value) == DFU_DESCRIPTOR_TYPE) {
+				pbuf = pdev->desc->get_config_desc(&len);
+				/* DFU descriptor at the end of the USB */
+				pbuf += len - 9U;
+				len = 9U;
+				len = MIN(len, req->length);
+			}
+
+			/* Start the transfer */
+			usb_core_transmit_ep0(pdev, pbuf, len);
+
+			break;
+
+		case USB_REQ_GET_INTERFACE:
+			/* Start the transfer */
+			usb_core_transmit_ep0(pdev, (uint8_t *)&hdfu->alt_setting, 1U);
+			break;
+
+		case USB_REQ_SET_INTERFACE:
+			hdfu->alt_setting = LOBYTE(req->value);
+			break;
+
+		default:
+			usb_core_ctl_error(pdev);
+			ret = USBD_FAIL;
+			break;
+		}
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static const struct usb_class usb_dfu = {
+	.init = usb_dfu_init,
+	.de_init = usb_dfu_de_init,
+	.setup = usb_dfu_setup,
+	.ep0_tx_sent = usb_dfu_ep0_tx_ready,
+	.ep0_rx_ready = usb_dfu_ep0_rx_ready,
+	.data_in = usb_dfu_data_in,
+	.data_out = usb_dfu_data_out,
+	.sof = usb_dfu_sof,
+	.iso_in_incomplete = usb_dfu_iso_in_incomplete,
+	.iso_out_incomplete = usb_dfu_iso_out_incomplete,
+};
+
+void usb_dfu_register(struct usb_handle *pdev, struct usb_dfu_handle *phandle)
+{
+	pdev->class = (struct usb_class *)&usb_dfu;
+	pdev->class_data = phandle;
+
+	phandle->dev_state = STATE_DFU_IDLE;
+	phandle->dev_status = DFU_ERROR_NONE;
+}
+
+int usb_dfu_loop(struct usb_handle *pdev, const struct usb_dfu_media *pmedia)
+{
+	uint32_t it_count;
+	enum usb_status ret;
+	struct usb_dfu_handle *hdfu = (struct usb_dfu_handle *)pdev->class_data;
+
+	hdfu->callback = pmedia;
+	usb_dfu_detach_req = false;
+	/* Continue to handle USB core IT to assure complete data transmission */
+	it_count = 100U;
+
+	/* DFU infinite loop until DETACH_REQ */
+	while (it_count != 0U) {
+		ret = usb_core_handle_it(pdev);
+		if (ret != USBD_OK) {
+			return -EIO;
+		}
+
+		/* Detach request received */
+		if (usb_dfu_detach_req) {
+			it_count--;
+		}
+	}
+
+	return 0;
+}