diff --git a/Makefile b/Makefile
index 16c85bc..b42bdc5 100644
--- a/Makefile
+++ b/Makefile
@@ -1011,6 +1011,7 @@
         NS_TIMER_SWITCH \
         OVERRIDE_LIBC \
         PL011_GENERIC_UART \
+        PLAT_RSS_NOT_SUPPORTED \
         PROGRAMMABLE_RESET_ADDRESS \
         PSCI_EXTENDED_STATE_ID \
         RESET_TO_BL31 \
@@ -1146,6 +1147,7 @@
         NS_TIMER_SWITCH \
         PL011_GENERIC_UART \
         PLAT_${PLAT} \
+        PLAT_RSS_NOT_SUPPORTED \
         PROGRAMMABLE_RESET_ADDRESS \
         PSCI_EXTENDED_STATE_ID \
         RAS_EXTENSION \
diff --git a/docs/about/maintainers.rst b/docs/about/maintainers.rst
index b9b5878..c62a6be 100644
--- a/docs/about/maintainers.rst
+++ b/docs/about/maintainers.rst
@@ -293,6 +293,20 @@
 :|G|: `odeprez`_
 :|F|: drivers/arm/gic/
 
+Message Handling Unit (MHU) driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+:|M|: David Vincze <david.vincze@arm.com>
+:|G|: `davidvincze`_
+:|F|: include/drivers/arm/mhu.h
+:|F|: drivers/arm/mhu
+
+Runtime Security Subsystem (RSS) comms driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+:|M|: David Vincze <david.vincze@arm.com>
+:|G|: `davidvincze`_
+:|F|: include/drivers/arm/rss_comms.h
+:|F|: drivers/arm/rss
+
 Libfdt wrappers
 ^^^^^^^^^^^^^^^
 :|M|: Madhukar Pappireddy <Madhukar.Pappireddy@arm.com>
@@ -331,6 +345,13 @@
 :|F|: drivers/fwu
 :|F|: include/drivers/fwu
 
+Platform Security Architecture (PSA) APIs
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+:|M|: Sandrine Bailleux <sandrine.bailleux@arm.com>
+:|G|: `sandrine-bailleux-arm`_
+:|F|: include/lib/psa
+:|F|: lib/psa
+
 System Control and Management Interface (SCMI) Server
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 :|M|: Etienne Carriere <etienne.carriere@st.com>
@@ -821,6 +842,7 @@
 .. _b49020: https://github.com/b49020
 .. _carlocaione: https://github.com/carlocaione
 .. _danh-arm: https://github.com/danh-arm
+.. _davidvincze: https://github.com/davidvincze
 .. _etienne-lms: https://github.com/etienne-lms
 .. _glneo: https://github.com/glneo
 .. _grandpaul: https://github.com/grandpaul
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index d2cda4d..742b6b5 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -994,6 +994,11 @@
   if FEAT_TRF is implemented. This flag can take the values 0 to 2, to align
   with the ``FEATURE_DETECTION`` mechanism. This flag is disabled by default.
 
+- ``PLAT_RSS_NOT_SUPPORTED``: Boolean option to enable the usage of the PSA
+  APIs on platforms that doesn't support RSS (providing Arm CCA HES
+  functionalities). When enabled (``1``), a mocked version of the APIs are used.
+  The default value is 0.
+
 GICv3 driver options
 --------------------
 
diff --git a/drivers/arm/mhu/mhu_v2_x.c b/drivers/arm/mhu/mhu_v2_x.c
new file mode 100644
index 0000000..3103b92
--- /dev/null
+++ b/drivers/arm/mhu/mhu_v2_x.c
@@ -0,0 +1,379 @@
+/*
+ * Copyright (c) 2020-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "mhu_v2_x.h"
+
+#define MHU_V2_X_MAX_CHANNELS		124
+#define MHU_V2_1_MAX_CHCOMB_INT		4
+#define ENABLE				0x1
+#define DISABLE				0x0
+#define CLEAR_INTR			0x1
+#define CH_PER_CH_COMB			0x20
+#define SEND_FRAME(p_mhu)		((struct mhu_v2_x_send_frame_t *)p_mhu)
+#define RECV_FRAME(p_mhu)		((struct mhu_v2_x_recv_frame_t *)p_mhu)
+
+#define MHU_MAJOR_REV_V2		0x1u
+#define MHU_MINOR_REV_2_0		0x0u
+#define MHU_MINOR_REV_2_1		0x1u
+
+struct mhu_v2_x_send_ch_window_t {
+	/* Offset: 0x00 (R/ ) Channel Status */
+	volatile uint32_t ch_st;
+	/* Offset: 0x04 (R/ ) Reserved */
+	volatile uint32_t reserved_0;
+	/* Offset: 0x08 (R/ ) Reserved */
+	volatile uint32_t reserved_1;
+	/* Offset: 0x0C ( /W) Channel Set */
+	volatile uint32_t ch_set;
+	/* Offset: 0x10 (R/ ) Channel Interrupt Status (Reserved in 2.0) */
+	volatile uint32_t ch_int_st;
+	/* Offset: 0x14 ( /W) Channel Interrupt Clear  (Reserved in 2.0) */
+	volatile uint32_t ch_int_clr;
+	/* Offset: 0x18 (R/W) Channel Interrupt Enable (Reserved in 2.0) */
+	volatile uint32_t ch_int_en;
+	/* Offset: 0x1C (R/ ) Reserved */
+	volatile uint32_t reserved_2;
+};
+
+struct mhu_v2_x_send_frame_t {
+	/* Offset: 0x000 ( / ) Sender Channel Window 0 -123 */
+	struct mhu_v2_x_send_ch_window_t send_ch_window[MHU_V2_X_MAX_CHANNELS];
+	/* Offset: 0xF80 (R/ ) Message Handling Unit Configuration */
+	volatile uint32_t mhu_cfg;
+	/* Offset: 0xF84 (R/W) Response Configuration */
+	volatile uint32_t resp_cfg;
+	/* Offset: 0xF88 (R/W) Access Request */
+	volatile uint32_t access_request;
+	/* Offset: 0xF8C (R/ ) Access Ready */
+	volatile uint32_t access_ready;
+	/* Offset: 0xF90 (R/ ) Interrupt Status */
+	volatile uint32_t int_st;
+	/* Offset: 0xF94 ( /W) Interrupt Clear */
+	volatile uint32_t int_clr;
+	/* Offset: 0xF98 (R/W) Interrupt Enable */
+	volatile uint32_t int_en;
+	/* Offset: 0xF9C (R/ ) Reserved */
+	volatile uint32_t reserved_0;
+	/* Offset: 0xFA0 (R/W) Channel Combined IRQ Stat (Reserved in 2.0) */
+	volatile uint32_t ch_comb_int_st[MHU_V2_1_MAX_CHCOMB_INT];
+	/* Offset: 0xFC4 (R/ ) Reserved */
+	volatile uint32_t reserved_1[6];
+	/* Offset: 0xFC8 (R/ ) Implementer Identification Register */
+	volatile uint32_t iidr;
+	/* Offset: 0xFCC (R/ ) Architecture Identification Register */
+	volatile uint32_t aidr;
+	/* Offset: 0xFD0 (R/ )  */
+	volatile uint32_t pid_1[4];
+	/* Offset: 0xFE0 (R/ )  */
+	volatile uint32_t pid_0[4];
+	/* Offset: 0xFF0 (R/ )  */
+	volatile uint32_t cid[4];
+};
+
+struct mhu_v2_x_rec_ch_window_t {
+	/* Offset: 0x00 (R/ ) Channel Status */
+	volatile uint32_t ch_st;
+	/* Offset: 0x04 (R/ ) Channel Status Masked */
+	volatile uint32_t ch_st_msk;
+	/* Offset: 0x08 ( /W) Channel Clear */
+	volatile uint32_t ch_clr;
+	/* Offset: 0x0C (R/ ) Reserved */
+	volatile uint32_t reserved_0;
+	/* Offset: 0x10 (R/ ) Channel Mask Status */
+	volatile uint32_t ch_msk_st;
+	/* Offset: 0x14 ( /W) Channel Mask Set */
+	volatile uint32_t ch_msk_set;
+	/* Offset: 0x18 ( /W) Channel Mask Clear */
+	volatile uint32_t ch_msk_clr;
+	/* Offset: 0x1C (R/ ) Reserved */
+	volatile uint32_t reserved_1;
+};
+
+struct mhu_v2_x_recv_frame_t {
+	/* Offset: 0x000 ( / ) Receiver Channel Window 0 -123 */
+	struct mhu_v2_x_rec_ch_window_t rec_ch_window[MHU_V2_X_MAX_CHANNELS];
+	/* Offset: 0xF80 (R/ ) Message Handling Unit Configuration */
+	volatile uint32_t mhu_cfg;
+	/* Offset: 0xF84 (R/ ) Reserved */
+	volatile uint32_t reserved_0[3];
+	/* Offset: 0xF90 (R/ ) Interrupt Status (Reserved in 2.0) */
+	volatile uint32_t int_st;
+	/* Offset: 0xF94 (R/ ) Interrupt Clear  (Reserved in 2.0) */
+	volatile uint32_t int_clr;
+	/* Offset: 0xF98 (R/W) Interrupt Enable (Reserved in 2.0) */
+	volatile uint32_t int_en;
+	/* Offset: 0xF9C (R/ ) Reserved  */
+	volatile uint32_t reserved_1;
+	/* Offset: 0xFA0 (R/ ) Channel Combined IRQ Stat (Reserved in 2.0) */
+	volatile uint32_t ch_comb_int_st[MHU_V2_1_MAX_CHCOMB_INT];
+	/* Offset: 0xFB0 (R/ ) Reserved */
+	volatile uint32_t reserved_2[6];
+	/* Offset: 0xFC8 (R/ ) Implementer Identification Register */
+	volatile uint32_t iidr;
+	/* Offset: 0xFCC (R/ ) Architecture Identification Register */
+	volatile uint32_t aidr;
+	/* Offset: 0xFD0 (R/ )  */
+	volatile uint32_t pid_1[4];
+	/* Offset: 0xFE0 (R/ )  */
+	volatile uint32_t pid_0[4];
+	/* Offset: 0xFF0 (R/ )  */
+	volatile uint32_t cid[4];
+};
+
+union mhu_v2_x_frame {
+	struct mhu_v2_x_send_frame_t send_frame;
+	struct mhu_v2_x_recv_frame_t recv_frame;
+};
+
+enum mhu_v2_x_error_t mhu_v2_x_driver_init(struct mhu_v2_x_dev_t *dev,
+	 enum mhu_v2_x_supported_revisions rev)
+{
+	uint32_t AIDR = 0;
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (dev->is_initialized) {
+		return MHU_V_2_X_ERR_ALREADY_INIT;
+	}
+
+	if (rev == MHU_REV_READ_FROM_HW) {
+		/* Read revision from HW */
+		if (dev->frame == MHU_V2_X_RECEIVER_FRAME) {
+			AIDR = p_mhu->recv_frame.aidr;
+		} else {
+			AIDR = p_mhu->send_frame.aidr;
+		}
+
+		/* Get bits 7:4 to read major revision */
+		if (((AIDR >> 4) & 0b1111) != MHU_MAJOR_REV_V2) {
+			/* Unsupported MHU version */
+			return MHU_V_2_X_ERR_UNSUPPORTED_VERSION;
+		} /* No need to save major version, driver only supports MHUv2 */
+
+		/* Get bits 3:0 to read minor revision */
+		dev->subversion = AIDR & 0b1111;
+
+		if (dev->subversion != MHU_MINOR_REV_2_0 &&
+			dev->subversion != MHU_MINOR_REV_2_1) {
+			/* Unsupported subversion */
+			return MHU_V_2_X_ERR_UNSUPPORTED_VERSION;
+		}
+	} else {
+		/* Revisions were provided by caller */
+		if (rev == MHU_REV_2_0) {
+			dev->subversion = MHU_MINOR_REV_2_0;
+		} else if (rev == MHU_REV_2_1) {
+			dev->subversion = MHU_MINOR_REV_2_1;
+		} else {
+			/* Unsupported subversion */
+			return MHU_V_2_X_ERR_UNSUPPORTED_VERSION;
+		} /* No need to save major version, driver only supports MHUv2 */
+	}
+
+	dev->is_initialized = true;
+
+	return MHU_V_2_X_ERR_NONE;
+}
+
+uint32_t mhu_v2_x_get_num_channel_implemented(const struct mhu_v2_x_dev_t *dev)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_SENDER_FRAME) {
+		return (SEND_FRAME(p_mhu))->mhu_cfg;
+	} else {
+		assert(dev->frame == MHU_V2_X_RECEIVER_FRAME);
+		return (RECV_FRAME(p_mhu))->mhu_cfg;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_send(const struct mhu_v2_x_dev_t *dev,
+	 uint32_t channel, uint32_t val)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_SENDER_FRAME) {
+		(SEND_FRAME(p_mhu))->send_ch_window[channel].ch_set = val;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_poll(const struct mhu_v2_x_dev_t *dev,
+	 uint32_t channel, uint32_t *value)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_SENDER_FRAME) {
+		*value = (SEND_FRAME(p_mhu))->send_ch_window[channel].ch_st;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_clear(const struct mhu_v2_x_dev_t *dev,
+	 uint32_t channel)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_RECEIVER_FRAME) {
+		(RECV_FRAME(p_mhu))->rec_ch_window[channel].ch_clr = UINT32_MAX;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_receive(
+	 const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t *value)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_RECEIVER_FRAME) {
+		*value = (RECV_FRAME(p_mhu))->rec_ch_window[channel].ch_st;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_mask_set(
+	 const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t mask)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_RECEIVER_FRAME) {
+		(RECV_FRAME(p_mhu))->rec_ch_window[channel].ch_msk_set = mask;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_channel_mask_clear(
+	 const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t mask)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame == MHU_V2_X_RECEIVER_FRAME) {
+		(RECV_FRAME(p_mhu))->rec_ch_window[channel].ch_msk_clr = mask;
+		return MHU_V_2_X_ERR_NONE;
+	} else {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+}
+enum mhu_v2_x_error_t mhu_v2_x_initiate_transfer(
+	 const struct mhu_v2_x_dev_t *dev)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame != MHU_V2_X_SENDER_FRAME) {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+
+	(SEND_FRAME(p_mhu))->access_request = ENABLE;
+
+	while (!((SEND_FRAME(p_mhu))->access_ready)) {
+		/* Wait in a loop for access ready signal to be high */
+		;
+	}
+
+	return MHU_V_2_X_ERR_NONE;
+}
+
+enum mhu_v2_x_error_t mhu_v2_x_close_transfer(const struct mhu_v2_x_dev_t *dev)
+{
+	union mhu_v2_x_frame *p_mhu;
+
+	assert(dev != NULL);
+
+	p_mhu = (union mhu_v2_x_frame *)dev->base;
+
+	if (!(dev->is_initialized)) {
+		return MHU_V_2_X_ERR_NOT_INIT;
+	}
+
+	if (dev->frame != MHU_V2_X_SENDER_FRAME) {
+		return MHU_V_2_X_ERR_INVALID_ARG;
+	}
+
+	(SEND_FRAME(p_mhu))->access_request = DISABLE;
+
+	return MHU_V_2_X_ERR_NONE;
+}
diff --git a/drivers/arm/mhu/mhu_v2_x.h b/drivers/arm/mhu/mhu_v2_x.h
new file mode 100644
index 0000000..10247d2
--- /dev/null
+++ b/drivers/arm/mhu/mhu_v2_x.h
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2020-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MHU_V2_X_H
+#define MHU_V2_X_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define MHU_2_X_INTR_NR2R_OFF		(0x0u)
+#define MHU_2_X_INTR_R2NR_OFF		(0x1u)
+#define MHU_2_1_INTR_CHCOMB_OFF		(0x2u)
+
+#define MHU_2_X_INTR_NR2R_MASK		(0x1u << MHU_2_X_INTR_NR2R_OFF)
+#define MHU_2_X_INTR_R2NR_MASK		(0x1u << MHU_2_X_INTR_R2NR_OFF)
+#define MHU_2_1_INTR_CHCOMB_MASK	(0x1u << MHU_2_1_INTR_CHCOMB_OFF)
+
+enum mhu_v2_x_frame_t {
+	MHU_V2_X_SENDER_FRAME   = 0x0u,
+	MHU_V2_X_RECEIVER_FRAME = 0x1u,
+};
+
+enum mhu_v2_x_supported_revisions {
+	MHU_REV_READ_FROM_HW = 0,
+	MHU_REV_2_0,
+	MHU_REV_2_1,
+};
+
+struct mhu_v2_x_dev_t {
+	uintptr_t base;
+	enum mhu_v2_x_frame_t frame;
+	uint32_t subversion;	/*!< Hardware subversion: v2.X */
+	bool is_initialized;	/*!< Indicates if the MHU driver
+				 *   is initialized and enabled
+				 */
+};
+
+/**
+ * MHU v2 error enumeration types.
+ */
+enum mhu_v2_x_error_t {
+	MHU_V_2_X_ERR_NONE			=  0,
+	MHU_V_2_X_ERR_NOT_INIT			= -1,
+	MHU_V_2_X_ERR_ALREADY_INIT		= -2,
+	MHU_V_2_X_ERR_UNSUPPORTED_VERSION	= -3,
+	MHU_V_2_X_ERR_INVALID_ARG		= -4,
+	MHU_V_2_X_ERR_GENERAL			= -5
+};
+
+/**
+ * Initializes the driver.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * rev		MHU revision (if can't be identified from HW).
+ *
+ * Reads the MHU hardware version.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * MHU revision only has to be specified when versions can't be read
+ * from HW (ARCH_MAJOR_REV reg reads as 0x0).
+ *
+ * This function doesn't check if dev is NULL.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_driver_init(struct mhu_v2_x_dev_t *dev,
+	enum mhu_v2_x_supported_revisions rev);
+
+/**
+ * Returns the number of channels implemented.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ *
+ * This function doesn't check if dev is NULL.
+ */
+uint32_t mhu_v2_x_get_num_channel_implemented(
+		const struct mhu_v2_x_dev_t *dev);
+
+/**
+ * Sends the value over a channel.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * channel	Channel to send the value over.
+ * val		Value to send.
+ *
+ * Sends the value over a channel.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ * This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_send(const struct mhu_v2_x_dev_t *dev,
+	uint32_t channel, uint32_t val);
+
+/**
+ * Polls sender channel status.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * channel	Channel to poll the status of.
+ * value	Pointer to variable that will store the value.
+ *
+ * Polls sender channel status.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ * This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_poll(const struct mhu_v2_x_dev_t *dev,
+	uint32_t channel, uint32_t *value);
+
+/**
+ * Clears the channel after the value is send over it.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * channel	Channel to clear.
+ *
+ * Clears the channel after the value is send over it.
+ *
+ * Returns mhu_v2_x_error_t error code..
+ *
+ * This function doesn't check if dev is NULL.
+ * This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_clear(const struct mhu_v2_x_dev_t *dev,
+	uint32_t channel);
+
+/**
+ * Receives the value over a channel.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * channel	Channel to receive the value from.
+ * value	Pointer to variable that will store the value.
+ *
+ * Receives the value over a channel.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ * This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_receive(
+	const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t *value);
+
+/**
+ * Sets bits in the Channel Mask.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ * channel	Which channel's mask to set.
+ * mask		Mask to be set over a receiver frame.
+ *
+ * Sets bits in the Channel Mask.
+ *
+ * Returns mhu_v2_x_error_t error code..
+ *
+ * This function doesn't check if dev is NULL.
+ *  This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_mask_set(
+	const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t mask);
+
+/**
+ * Clears bits in the Channel Mask.
+ *
+ * dev	MHU device struct mhu_v2_x_dev_t.
+ * channel	Which channel's mask to clear.
+ * mask	Mask to be clear over a receiver frame.
+ *
+ * Clears bits in the Channel Mask.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ *  This function doesn't check if channel is implemented.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_channel_mask_clear(
+	const struct mhu_v2_x_dev_t *dev, uint32_t channel, uint32_t mask);
+
+/**
+ * Initiates a MHU transfer with the handshake signals.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ *
+ * Initiates a MHU transfer with the handshake signals in a blocking mode.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_initiate_transfer(
+	const struct mhu_v2_x_dev_t *dev);
+
+/**
+ * Closes a MHU transfer with the handshake signals.
+ *
+ * dev		MHU device struct mhu_v2_x_dev_t.
+ *
+ * Closes a MHU transfer with the handshake signals in a blocking mode.
+ *
+ * Returns mhu_v2_x_error_t error code.
+ *
+ * This function doesn't check if dev is NULL.
+ */
+enum mhu_v2_x_error_t mhu_v2_x_close_transfer(
+	const struct mhu_v2_x_dev_t *dev);
+
+#endif /* MHU_V2_X_H */
diff --git a/drivers/arm/mhu/mhu_wrapper_v2_x.c b/drivers/arm/mhu/mhu_wrapper_v2_x.c
new file mode 100644
index 0000000..d8b7cfd
--- /dev/null
+++ b/drivers/arm/mhu/mhu_wrapper_v2_x.c
@@ -0,0 +1,302 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <drivers/arm/mhu.h>
+
+#include "mhu_v2_x.h"
+
+#define MHU_NOTIFY_VALUE	(1234u)
+
+/*
+ * MHU devices for host:
+ * HSE: Host to Secure Enclave (sender device)
+ * SEH: Secure Enclave to Host (receiver device)
+ */
+struct mhu_v2_x_dev_t MHU1_HSE_DEV = {0, MHU_V2_X_SENDER_FRAME};
+struct mhu_v2_x_dev_t MHU1_SEH_DEV = {0, MHU_V2_X_RECEIVER_FRAME};
+
+static enum mhu_error_t error_mapping_to_mhu_error_t(enum mhu_v2_x_error_t err)
+{
+	switch (err) {
+	case MHU_V_2_X_ERR_NONE:
+		return MHU_ERR_NONE;
+	case MHU_V_2_X_ERR_NOT_INIT:
+		return MHU_ERR_NOT_INIT;
+	case MHU_V_2_X_ERR_ALREADY_INIT:
+		return MHU_ERR_ALREADY_INIT;
+	case MHU_V_2_X_ERR_UNSUPPORTED_VERSION:
+		return MHU_ERR_UNSUPPORTED_VERSION;
+	case MHU_V_2_X_ERR_INVALID_ARG:
+		return MHU_ERR_INVALID_ARG;
+	case MHU_V_2_X_ERR_GENERAL:
+		return MHU_ERR_GENERAL;
+	default:
+		return MHU_ERR_GENERAL;
+	}
+}
+
+static enum mhu_v2_x_error_t signal_and_wait_for_clear(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_HSE_DEV;
+	uint32_t val = MHU_NOTIFY_VALUE;
+	/* Using the last channel for notifications */
+	uint32_t channel_notify = mhu_v2_x_get_num_channel_implemented(dev) - 1;
+
+	err = mhu_v2_x_channel_send(dev, channel_notify, val);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return err;
+	}
+
+	do {
+		err = mhu_v2_x_channel_poll(dev, channel_notify, &val);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			break;
+		}
+	} while (val != 0);
+
+	return err;
+}
+
+static enum mhu_v2_x_error_t wait_for_signal(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t val = 0;
+	/* Using the last channel for notifications */
+	uint32_t channel_notify = mhu_v2_x_get_num_channel_implemented(dev) - 1;
+
+	do {
+		err = mhu_v2_x_channel_receive(dev, channel_notify, &val);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			break;
+		}
+	} while (val != MHU_NOTIFY_VALUE);
+
+	return err;
+}
+
+static enum mhu_v2_x_error_t clear_and_wait_for_next_signal(void)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t i;
+
+	/* Clear all channels */
+	for (i = 0; i < num_channels; ++i) {
+		err = mhu_v2_x_channel_clear(dev, i);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return err;
+		}
+	}
+
+	return wait_for_signal();
+}
+
+enum mhu_error_t mhu_init_sender(uintptr_t mhu_sender_base)
+{
+	enum mhu_v2_x_error_t err;
+
+	assert(mhu_sender_base != (uintptr_t)NULL);
+
+	MHU1_HSE_DEV.base = mhu_sender_base;
+
+	err = mhu_v2_x_driver_init(&MHU1_HSE_DEV, MHU_REV_READ_FROM_HW);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+enum mhu_error_t mhu_init_receiver(uintptr_t mhu_receiver_base)
+{
+	enum mhu_v2_x_error_t err;
+	uint32_t num_channels, i;
+
+	assert(mhu_receiver_base != (uintptr_t)NULL);
+
+	MHU1_SEH_DEV.base = mhu_receiver_base;
+
+	err = mhu_v2_x_driver_init(&MHU1_SEH_DEV, MHU_REV_READ_FROM_HW);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	num_channels = mhu_v2_x_get_num_channel_implemented(&MHU1_SEH_DEV);
+
+	/* Mask all channels except the notifying channel */
+	for (i = 0; i < (num_channels - 1); ++i) {
+		err = mhu_v2_x_channel_mask_set(&MHU1_SEH_DEV, i, UINT32_MAX);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	/* The last channel is used for notifications */
+	err = mhu_v2_x_channel_mask_clear(
+		&MHU1_SEH_DEV, (num_channels - 1), UINT32_MAX);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+/*
+ * Public function. See mhu.h
+ *
+ * The basic steps of transferring a message:
+ * 1.	Initiate MHU transfer.
+ * 2.	Send over the size of the payload on Channel 1. It is the very first
+ *	4 Bytes of the transfer. Continue with Channel 2.
+ * 3.	Send over the payload, writing the channels one after the other
+ *	(4 Bytes each). The last available channel is reserved for controlling
+ *	the transfer.
+ *	When the last channel is reached or no more data is left, STOP.
+ * 4.	Notify the receiver using the last channel and wait for acknowledge.
+ *	If there is still data to transfer, jump to step 3. Otherwise, proceed.
+ * 5.	Close MHU transfer.
+ *
+ */
+enum mhu_error_t mhu_send_data(const uint8_t *send_buffer, size_t size)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_HSE_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t chan = 0;
+	uint32_t i;
+	uint32_t *p;
+
+	/* For simplicity, require the send_buffer to be 4-byte aligned */
+	if ((uintptr_t)send_buffer & 0x3U) {
+		return MHU_ERR_INVALID_ARG;
+	}
+
+	err = mhu_v2_x_initiate_transfer(dev);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	/* First send over the size of the actual message */
+	err = mhu_v2_x_channel_send(dev, chan, (uint32_t)size);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+	chan++;
+
+	p = (uint32_t *)send_buffer;
+	for (i = 0; i < size; i += 4) {
+		err = mhu_v2_x_channel_send(dev, chan, *p++);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+		if (++chan == (num_channels - 1)) {
+			err = signal_and_wait_for_clear();
+			if (err != MHU_V_2_X_ERR_NONE) {
+				return error_mapping_to_mhu_error_t(err);
+			}
+			chan = 0;
+		}
+	}
+
+	/* Signal the end of transfer.
+	 *   It's not required to send a signal when the message was
+	 *   perfectly-aligned (num_channels - 1 channels were used in the last
+	 *   round) preventing it from signaling twice at the end of transfer.
+	 */
+	if (chan != 0) {
+		err = signal_and_wait_for_clear();
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	err = mhu_v2_x_close_transfer(dev);
+	return error_mapping_to_mhu_error_t(err);
+}
+
+/*
+ * Public function. See mhu.h
+ *
+ * The basic steps of receiving a message:
+ * 1.	Read the size of the payload from Channel 1. It is the very first
+ *	4 Bytes of the transfer. Continue with Channel 2.
+ * 2.	Receive the payload, read the channels one after the other
+ *	(4 Bytes each). The last available channel is reserved for controlling
+ *	the transfer.
+ *	When the last channel is reached clear all the channels
+ *	(also sending an acknowledge on the last channel).
+ * 3.	If there is still data to receive wait for a notification on the last
+ *	channel and jump to step 2 as soon as it arrived. Otherwise, proceed.
+ * 4.	End of transfer.
+ *
+ */
+enum mhu_error_t mhu_receive_data(uint8_t *receive_buffer, size_t *size)
+{
+	enum mhu_v2_x_error_t err;
+	struct mhu_v2_x_dev_t *dev = &MHU1_SEH_DEV;
+	uint32_t num_channels = mhu_v2_x_get_num_channel_implemented(dev);
+	uint32_t chan = 0;
+	uint32_t message_len;
+	uint32_t i;
+	uint32_t *p;
+
+	/* For simplicity, require:
+	 * - the receive_buffer to be 4-byte aligned,
+	 * - the buffer size to be a multiple of 4.
+	 */
+	if (((uintptr_t)receive_buffer & 0x3U) || (*size & 0x3U)) {
+		return MHU_ERR_INVALID_ARG;
+	}
+
+	/* Busy wait for incoming reply */
+	err = wait_for_signal();
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+
+	/* The first word is the length of the actual message */
+	err = mhu_v2_x_channel_receive(dev, chan, &message_len);
+	if (err != MHU_V_2_X_ERR_NONE) {
+		return error_mapping_to_mhu_error_t(err);
+	}
+	chan++;
+
+	if (message_len > *size) {
+		/* Message buffer too small */
+		*size = message_len;
+		return MHU_ERR_BUFFER_TOO_SMALL;
+	}
+
+	p = (uint32_t *)receive_buffer;
+	for (i = 0; i < message_len; i += 4) {
+		err = mhu_v2_x_channel_receive(dev, chan, p++);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+
+		/* Only wait for next transfer if there is still missing data */
+		if (++chan == (num_channels - 1) && (message_len - i) > 4) {
+			/* Busy wait for next transfer */
+			err = clear_and_wait_for_next_signal();
+			if (err != MHU_V_2_X_ERR_NONE) {
+				return error_mapping_to_mhu_error_t(err);
+			}
+			chan = 0;
+		}
+	}
+
+	/* Clear all channels */
+	for (i = 0; i < num_channels; ++i) {
+		err = mhu_v2_x_channel_clear(dev, i);
+		if (err != MHU_V_2_X_ERR_NONE) {
+			return error_mapping_to_mhu_error_t(err);
+		}
+	}
+
+	*size = message_len;
+
+	return MHU_ERR_NONE;
+}
diff --git a/drivers/arm/rss/rss_comms.c b/drivers/arm/rss/rss_comms.c
new file mode 100644
index 0000000..28a4925
--- /dev/null
+++ b/drivers/arm/rss/rss_comms.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <common/debug.h>
+#include <drivers/arm/mhu.h>
+#include <drivers/arm/rss_comms.h>
+#include <initial_attestation.h>
+#include <psa/client.h>
+
+#include <platform_def.h>
+
+#define TYPE_OFFSET	U(16)
+#define TYPE_MASK	(0xFFFFUL << TYPE_OFFSET)
+#define IN_LEN_OFFSET	U(8)
+#define IN_LEN_MASK	(0xFFUL << IN_LEN_OFFSET)
+#define OUT_LEN_OFFSET	U(0)
+#define OUT_LEN_MASK	(0xFFUL << OUT_LEN_OFFSET)
+
+#define PARAM_PACK(type, in_len, out_len)			  \
+	(((((uint32_t)type) << TYPE_OFFSET) & TYPE_MASK)	| \
+	 ((((uint32_t)in_len) << IN_LEN_OFFSET) & IN_LEN_MASK)	| \
+	 ((((uint32_t)out_len) << OUT_LEN_OFFSET) & OUT_LEN_MASK))
+
+#define PARAM_UNPACK_IN_LEN(ctrl_param) \
+	((size_t)(((ctrl_param) & IN_LEN_MASK) >> IN_LEN_OFFSET))
+
+/* Message types */
+struct __packed packed_psa_call_t {
+	uint8_t protocol_ver;
+	uint8_t seq_num;
+	uint16_t client_id;
+	psa_handle_t handle;
+	uint32_t ctrl_param; /* type, in_len, out_len */
+	uint16_t io_size[4];
+};
+
+struct __packed packed_psa_reply_t {
+	uint8_t protocol_ver;
+	uint8_t seq_num;
+	uint16_t client_id;
+	int32_t return_val;
+	uint16_t out_size[4];
+};
+
+/*
+ * In the current implementation the RoT Service request that requires the
+ * biggest message buffer is the RSS_ATTEST_GET_TOKEN. The maximum required
+ * buffer size is calculated based on the platform-specific needs of
+ * this request.
+ */
+#define MAX_REQUEST_PAYLOAD_SIZE	(PSA_INITIAL_ATTEST_CHALLENGE_SIZE_64 \
+					 + PLAT_ATTEST_TOKEN_MAX_SIZE)
+
+/* Buffer to store the messages to be sent/received. */
+static uint8_t message_buf[MAX_REQUEST_PAYLOAD_SIZE] __aligned(4);
+
+static int32_t pack_params(const psa_invec *invecs,
+			   size_t in_len,
+			   uint8_t *buf,
+			   size_t *buf_len)
+{
+	uint32_t i;
+	size_t payload_size = 0U;
+
+	for (i = 0U; i < in_len; ++i) {
+		if (invecs[i].len > *buf_len - payload_size) {
+			return -1;
+		}
+		memcpy(buf + payload_size, invecs[i].base, invecs[i].len);
+		payload_size += invecs[i].len;
+	}
+
+	*buf_len = payload_size;
+	return 0;
+}
+
+static int serialise_message(const struct packed_psa_call_t *msg,
+			     const psa_invec *invecs,
+			     uint8_t *payload_buf,
+			     size_t *payload_len)
+{
+	size_t message_len = 0U;
+	size_t len;
+
+	/* Copy the message header into the payload buffer. */
+	len = sizeof(*msg);
+	if (len > *payload_len) {
+		ERROR("[RSS-COMMS] Message buffer too small.\n");
+		return -1;
+	}
+	memcpy(payload_buf, (const void *)msg, len);
+	message_len += len;
+
+	/* The input data will follow the message header in the payload buffer. */
+	len = *payload_len - message_len;
+	if (pack_params(invecs, PARAM_UNPACK_IN_LEN(msg->ctrl_param),
+			payload_buf + message_len, &len) != 0) {
+		ERROR("[RSS-COMMS] Message buffer too small.\n");
+		return -1;
+	}
+	message_len += len;
+
+	*payload_len = message_len;
+	return 0;
+}
+
+static void unpack_params(const uint8_t *buf,
+			  psa_outvec *outvecs,
+			  size_t out_len)
+{
+	size_t i;
+
+	for (i = 0U; i < out_len; ++i) {
+		memcpy(outvecs[i].base, buf, outvecs[i].len);
+		buf += outvecs[i].len;
+	}
+}
+
+static void deserialise_reply(struct packed_psa_reply_t *reply,
+			      psa_outvec *outvecs,
+			      size_t outlen,
+			      const uint8_t *message,
+			      size_t message_len)
+{
+	uint32_t i;
+
+	memcpy(reply, message, sizeof(*reply));
+
+	/* Outvecs */
+	for (i = 0U; i < outlen; ++i) {
+		outvecs[i].len = reply->out_size[i];
+	}
+
+	unpack_params(message + sizeof(*reply), outvecs, outlen);
+}
+
+psa_status_t psa_call(psa_handle_t handle, int32_t type,
+		      const psa_invec *in_vec, size_t in_len,
+		      psa_outvec *out_vec, size_t out_len)
+{
+	enum mhu_error_t err;
+	static uint32_t seq_num = 1U;
+	struct packed_psa_call_t msg = {
+		.protocol_ver = 0U,
+		.seq_num = seq_num,
+		/* No need to distinguish callers (currently concurrent calls are not supported). */
+		.client_id = 1U,
+		.handle = handle,
+		.ctrl_param = PARAM_PACK(type, in_len, out_len),
+	};
+
+	struct packed_psa_reply_t reply = {0};
+	size_t message_size;
+	uint32_t i;
+
+	/* Fill msg iovec lengths */
+	for (i = 0U; i < in_len; ++i) {
+		msg.io_size[i] = in_vec[i].len;
+	}
+	for (i = 0U; i < out_len; ++i) {
+		msg.io_size[in_len + i] = out_vec[i].len;
+	}
+
+	message_size = sizeof(message_buf);
+	if (serialise_message(&msg, in_vec, message_buf, &message_size)) {
+		/* Local buffer is probably too small. */
+		return PSA_ERROR_INSUFFICIENT_MEMORY;
+	}
+
+	err = mhu_send_data(message_buf, message_size);
+	if (err != MHU_ERR_NONE) {
+		return PSA_ERROR_COMMUNICATION_FAILURE;
+	}
+
+	message_size = sizeof(message_buf);
+#if DEBUG
+	/*
+	 * Poisoning the message buffer (with a known pattern).
+	 * Helps in detecting hypothetical RSS communication bugs.
+	 */
+	memset(message_buf, 0xA5, message_size);
+#endif
+	err = mhu_receive_data(message_buf, &message_size);
+	if (err != MHU_ERR_NONE) {
+		return PSA_ERROR_COMMUNICATION_FAILURE;
+	}
+
+	deserialise_reply(&reply, out_vec, out_len, message_buf, message_size);
+
+	seq_num++;
+
+	VERBOSE("[RSS-COMMS] Received reply\n");
+	VERBOSE("protocol_ver=%d\n", reply.protocol_ver);
+	VERBOSE("seq_num=%d\n", reply.seq_num);
+	VERBOSE("client_id=%d\n", reply.client_id);
+	VERBOSE("return_val=%d\n", reply.return_val);
+	VERBOSE("out_size[0]=%d\n", reply.out_size[0]);
+
+	return reply.return_val;
+}
+
+int rss_comms_init(uintptr_t mhu_sender_base, uintptr_t mhu_receiver_base)
+{
+	enum mhu_error_t err;
+
+	err = mhu_init_sender(mhu_sender_base);
+	if (err != MHU_ERR_NONE) {
+		ERROR("[RSS-COMMS] Host to RSS MHU driver initialization failed: %d\n", err);
+		return -1;
+	}
+
+	err = mhu_init_receiver(mhu_receiver_base);
+	if (err != MHU_ERR_NONE) {
+		ERROR("[RSS-COMMS] RSS to Host MHU driver initialization failed: %d\n", err);
+		return -1;
+	}
+
+	return 0;
+}
diff --git a/drivers/measured_boot/rss/rss_measured_boot.c b/drivers/measured_boot/rss/rss_measured_boot.c
new file mode 100644
index 0000000..fe2baf0
--- /dev/null
+++ b/drivers/measured_boot/rss/rss_measured_boot.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <assert.h>
+#include <stdint.h>
+
+#include <common/debug.h>
+#include <drivers/auth/crypto_mod.h>
+#include <drivers/measured_boot/rss/rss_measured_boot.h>
+#include <lib/psa/measured_boot.h>
+#include <psa/crypto_types.h>
+#include <psa/crypto_values.h>
+#include <psa/error.h>
+
+#define MBOOT_ALG_SHA512 0
+#define MBOOT_ALG_SHA384 1
+#define MBOOT_ALG_SHA256 2
+
+#if MBOOT_ALG_ID == MBOOT_ALG_SHA512
+#define	CRYPTO_MD_ID		CRYPTO_MD_SHA512
+#define PSA_CRYPTO_MD_ID	PSA_ALG_SHA_512
+#elif MBOOT_ALG_ID == MBOOT_ALG_SHA384
+#define	CRYPTO_MD_ID		CRYPTO_MD_SHA384
+#define PSA_CRYPTO_MD_ID	PSA_ALG_SHA_384
+#elif MBOOT_ALG_ID == MBOOT_ALG_SHA256
+#define	CRYPTO_MD_ID		CRYPTO_MD_SHA256
+#define PSA_CRYPTO_MD_ID	PSA_ALG_SHA_256
+#else
+#  error Invalid Measured Boot algorithm.
+#endif /* MBOOT_ALG_ID */
+
+/* Pointer to struct rss_mboot_metadata */
+static struct rss_mboot_metadata *plat_metadata_ptr;
+
+/* Functions' declarations */
+void rss_measured_boot_init(void)
+{
+	/* At this point it is expected that communication channel over MHU
+	 * is already initialised by platform init.
+	 */
+
+	/* Get pointer to platform's struct rss_mboot_metadata structure */
+	plat_metadata_ptr = plat_rss_mboot_get_metadata();
+	assert(plat_metadata_ptr != NULL);
+}
+
+int rss_mboot_measure_and_record(uintptr_t data_base, uint32_t data_size,
+				 uint32_t data_id)
+{
+	unsigned char hash_data[CRYPTO_MD_MAX_SIZE];
+	int rc;
+	psa_status_t ret;
+	const struct rss_mboot_metadata *metadata_ptr = plat_metadata_ptr;
+
+	/* Get the metadata associated with this image. */
+	while ((metadata_ptr->id != RSS_MBOOT_INVALID_ID) &&
+		(metadata_ptr->id != data_id)) {
+		metadata_ptr++;
+	}
+
+	/* If image is not present in metadata array then skip */
+	if (metadata_ptr->id == RSS_MBOOT_INVALID_ID) {
+		return 0;
+	}
+
+	/* Calculate hash */
+	rc = crypto_mod_calc_hash(CRYPTO_MD_ID,
+				  (void *)data_base, data_size, hash_data);
+	if (rc != 0) {
+		return rc;
+	}
+
+	ret = rss_measured_boot_extend_measurement(
+						metadata_ptr->slot,
+						metadata_ptr->signer_id,
+						metadata_ptr->signer_id_size,
+						metadata_ptr->version,
+						metadata_ptr->version_size,
+						PSA_CRYPTO_MD_ID,
+						metadata_ptr->sw_type,
+						metadata_ptr->sw_type_size,
+						hash_data,
+						MBOOT_DIGEST_SIZE,
+						metadata_ptr->lock_measurement);
+	if (ret != PSA_SUCCESS) {
+		return ret;
+	}
+
+	return 0;
+}
+
+int rss_mboot_set_signer_id(unsigned int img_id,
+			    const void *pk_ptr,
+			    size_t pk_len)
+{
+	unsigned char hash_data[CRYPTO_MD_MAX_SIZE];
+	struct rss_mboot_metadata *metadata_ptr = plat_metadata_ptr;
+	int rc;
+
+	/* Get the metadata associated with this image. */
+	while ((metadata_ptr->id != RSS_MBOOT_INVALID_ID) &&
+		(metadata_ptr->id != img_id)) {
+		metadata_ptr++;
+	}
+
+	/* If image is not present in metadata array then skip */
+	if (metadata_ptr->id == RSS_MBOOT_INVALID_ID) {
+		return 0;
+	}
+
+	/* Calculate public key hash */
+	rc = crypto_mod_calc_hash(CRYPTO_MD_ID, (void *)pk_ptr,
+				  pk_len, hash_data);
+	if (rc != 0) {
+		return rc;
+	}
+
+	/* Update metadata struct with the received signer_id */
+	(void)memcpy(metadata_ptr->signer_id, hash_data, MBOOT_DIGEST_SIZE);
+	metadata_ptr->signer_id_size = MBOOT_DIGEST_SIZE;
+
+	return 0;
+}
diff --git a/drivers/measured_boot/rss/rss_measured_boot.mk b/drivers/measured_boot/rss/rss_measured_boot.mk
new file mode 100644
index 0000000..01545af
--- /dev/null
+++ b/drivers/measured_boot/rss/rss_measured_boot.mk
@@ -0,0 +1,35 @@
+#
+# Copyright (c) 2022, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+# Hash algorithm for measured boot
+# SHA-256 (or stronger) is required.
+# TODO: The measurement algorithm incorrectly suggests that the TPM backend
+#       is used which may not be the case. It is currently being worked on and
+#       soon TPM_HASH_ALG will be replaced by a more generic name.
+TPM_HASH_ALG			:=	sha256
+
+ifeq (${TPM_HASH_ALG}, sha512)
+    MBOOT_ALG_ID		:=	MBOOT_ALG_SHA512
+    MBOOT_DIGEST_SIZE		:=	64U
+else ifeq (${TPM_HASH_ALG}, sha384)
+    MBOOT_ALG_ID		:=	MBOOT_ALG_SHA384
+    MBOOT_DIGEST_SIZE		:=	48U
+else
+    MBOOT_ALG_ID		:=	MBOOT_ALG_SHA256
+    MBOOT_DIGEST_SIZE		:=	32U
+endif #TPM_HASH_ALG
+
+# Set definitions for Measured Boot driver.
+$(eval $(call add_defines,\
+    $(sort \
+        MBOOT_ALG_ID \
+        MBOOT_DIGEST_SIZE \
+        MBOOT_RSS_BACKEND \
+)))
+
+MEASURED_BOOT_SRC_DIR	:= drivers/measured_boot/rss/
+
+MEASURED_BOOT_SOURCES	+= ${MEASURED_BOOT_SRC_DIR}rss_measured_boot.c
diff --git a/include/drivers/arm/mhu.h b/include/drivers/arm/mhu.h
new file mode 100644
index 0000000..7745bd9
--- /dev/null
+++ b/include/drivers/arm/mhu.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MHU_H
+#define MHU_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/**
+ * Generic MHU error enumeration types.
+ */
+enum mhu_error_t {
+	MHU_ERR_NONE			=  0,
+	MHU_ERR_NOT_INIT		= -1,
+	MHU_ERR_ALREADY_INIT		= -2,
+	MHU_ERR_UNSUPPORTED_VERSION	= -3,
+	MHU_ERR_UNSUPPORTED		= -4,
+	MHU_ERR_INVALID_ARG		= -5,
+	MHU_ERR_BUFFER_TOO_SMALL	= -6,
+	MHU_ERR_GENERAL			= -7,
+};
+
+/**
+ * Initializes sender MHU.
+ *
+ * mhu_sender_base	Base address of sender MHU.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * This function must be called before mhu_send_data().
+ */
+enum mhu_error_t mhu_init_sender(uintptr_t mhu_sender_base);
+
+
+/**
+ * Initializes receiver MHU.
+ *
+ * mhu_receiver_base	Base address of receiver MHU.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * This function must be called before mhu_receive_data().
+ */
+enum mhu_error_t mhu_init_receiver(uintptr_t mhu_receiver_base);
+
+/**
+ * Sends data over MHU.
+ *
+ * send_buffer		Pointer to buffer containing the data to be transmitted.
+ * size			Size of the data to be transmitted in bytes.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * The send_buffer must be 4-byte aligned and its length must be at least
+ * (4 - (size % 4)) bytes bigger than the data size to prevent buffer
+ * over-reading.
+ */
+enum mhu_error_t mhu_send_data(const uint8_t *send_buffer, size_t size);
+
+/**
+ * Receives data from MHU.
+ *
+ * receive_buffer	Pointer the buffer where to store the received data.
+ * size			As input the size of the receive_buffer, as output the
+ *			number of bytes received. As a limitation,
+ *			the size of the buffer must be a multiple of 4.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * The receive_buffer must be 4-byte aligned and its length must be a
+ * multiple of 4.
+ */
+enum mhu_error_t mhu_receive_data(uint8_t *receive_buffer, size_t *size);
+
+#endif /* MHU_H */
diff --git a/include/drivers/arm/rss_comms.h b/include/drivers/arm/rss_comms.h
new file mode 100644
index 0000000..b96c79f
--- /dev/null
+++ b/include/drivers/arm/rss_comms.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef RSS_COMMS_H
+#define RSS_COMMS_H
+
+#include <stdint.h>
+
+int rss_comms_init(uintptr_t mhu_sender_base, uintptr_t mhu_receiver_base);
+
+#endif /* RSS_COMMS_H */
diff --git a/include/drivers/measured_boot/rss/rss_measured_boot.h b/include/drivers/measured_boot/rss/rss_measured_boot.h
new file mode 100644
index 0000000..fe88576
--- /dev/null
+++ b/include/drivers/measured_boot/rss/rss_measured_boot.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef RSS_MEASURED_BOOT_H
+#define RSS_MEASURED_BOOT_H
+
+#include <stdint.h>
+
+#include <common/debug.h>
+#include <measured_boot.h>
+
+#define RSS_MBOOT_INVALID_ID	UINT32_MAX
+
+/*
+ * Each boot measurement has some metadata (i.e. a string) that identifies
+ * what was measured and how. The sw_type field of the rss_mboot_metadata
+ * structure represents the role of the software component that was measured.
+ * The below macros define strings suitable for the sw_type.
+ * The key thing is to choose meaningful strings so that when the attestation
+ * token is verified, then the different components can be identified.
+ */
+#define RSS_MBOOT_BL2_STRING		"BL_2"
+#define RSS_MBOOT_BL31_STRING		"SECURE_RT_EL3"
+#define RSS_MBOOT_HW_CONFIG_STRING	"HW_CONFIG"
+#define RSS_MBOOT_FW_CONFIG_STRING	"FW_CONFIG"
+#define RSS_MBOOT_TB_FW_CONFIG_STRING	"TB_FW_CONFIG"
+#define RSS_MBOOT_SOC_FW_CONFIG_STRING	"SOC_FW_CONFIG"
+#define RSS_MBOOT_RMM_STRING		"RMM"
+
+
+struct rss_mboot_metadata {
+	unsigned int id;
+	uint8_t slot;
+	uint8_t signer_id[SIGNER_ID_MAX_SIZE];
+	size_t  signer_id_size;
+	uint8_t version[VERSION_MAX_SIZE];
+	size_t  version_size;
+	uint8_t sw_type[SW_TYPE_MAX_SIZE];
+	size_t  sw_type_size;
+	bool    lock_measurement;
+};
+
+/* Functions' declarations */
+void rss_measured_boot_init(void);
+struct rss_mboot_metadata *plat_rss_mboot_get_metadata(void);
+int rss_mboot_measure_and_record(uintptr_t data_base, uint32_t data_size,
+				 uint32_t data_id);
+
+/* TODO: These metadata are currently not available during TF-A boot */
+int rss_mboot_set_signer_id(unsigned int img_id, const void *pk_ptr, size_t pk_len);
+
+#endif /* RSS_MEASURED_BOOT_H */
diff --git a/include/lib/psa/initial_attestation.h b/include/lib/psa/initial_attestation.h
new file mode 100644
index 0000000..93169f0
--- /dev/null
+++ b/include/lib/psa/initial_attestation.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_INITIAL_ATTESTATION_H
+#define PSA_INITIAL_ATTESTATION_H
+
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "psa/error.h"
+
+/*
+ * Initial attestation API version is: 1.0.0
+ */
+#define PSA_INITIAL_ATTEST_API_VERSION_MAJOR	(1)
+#define PSA_INITIAL_ATTEST_API_VERSION_MINOR	(0)
+
+/* The allowed size of input challenge in bytes. */
+#define PSA_INITIAL_ATTEST_CHALLENGE_SIZE_32	32U
+#define PSA_INITIAL_ATTEST_CHALLENGE_SIZE_48	48U
+#define PSA_INITIAL_ATTEST_CHALLENGE_SIZE_64	64U
+
+/* Initial Attestation message types that distinguish Attest services. */
+#define RSS_ATTEST_GET_TOKEN		1001U
+#define RSS_ATTEST_GET_TOKEN_SIZE	1002U
+#define RSS_ATTEST_GET_DELEGATED_KEY	1003U
+
+/**
+ * Get the platform attestation token.
+ *
+ * auth_challenge	Pointer to buffer where challenge input is stored. This
+ *			must be the hash of the public part of the delegated
+ *			attestation key.
+ * challenge_size	Size of challenge object in bytes.
+ * token_buf		Pointer to the buffer where attestation token will be
+ *			stored.
+ * token_buf_size	Size of allocated buffer for token, in bytes.
+ * token_size		Size of the token that has been returned, in bytes.
+ *
+ * Returns error code as specified in psa_status_t.
+ */
+psa_status_t
+psa_initial_attest_get_token(const uint8_t *auth_challenge,
+			     size_t         challenge_size,
+			     uint8_t       *token_buf,
+			     size_t         token_buf_size,
+			     size_t        *token_size);
+
+#endif /* PSA_INITIAL_ATTESTATION_H */
diff --git a/include/lib/psa/measured_boot.h b/include/lib/psa/measured_boot.h
new file mode 100644
index 0000000..bdb79d5
--- /dev/null
+++ b/include/lib/psa/measured_boot.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_MEASURED_BOOT_H
+#define PSA_MEASURED_BOOT_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "psa/error.h"
+
+/* Minimum measurement value size that can be requested to store */
+#define MEASUREMENT_VALUE_MIN_SIZE	32U
+/* Maximum measurement value size that can be requested to store */
+#define MEASUREMENT_VALUE_MAX_SIZE	64U
+/* Minimum signer id size that can be requested to store */
+#define SIGNER_ID_MIN_SIZE		MEASUREMENT_VALUE_MIN_SIZE
+/* Maximum signer id size that can be requested to store */
+#define SIGNER_ID_MAX_SIZE		MEASUREMENT_VALUE_MAX_SIZE
+/* The theoretical maximum image version is: "255.255.65535\0" */
+#define VERSION_MAX_SIZE		14U
+/* Example sw_type: "BL_2, BL_33, etc." */
+#define SW_TYPE_MAX_SIZE		20U
+#define NUM_OF_MEASUREMENT_SLOTS	32U
+
+
+/**
+ * Extends and stores a measurement to the requested slot.
+ *
+ * index			Slot number in which measurement is to be stored
+ * signer_id			Pointer to signer_id buffer.
+ * signer_id_size		Size of the signer_id buffer in bytes.
+ * version			Pointer to version buffer.
+ * version_size			Size of the version buffer in bytes.
+ * measurement_algo		Algorithm identifier used for measurement.
+ * sw_type			Pointer to sw_type buffer.
+ * sw_type_size			Size of the sw_type buffer in bytes.
+ * measurement_value		Pointer to measurement_value buffer.
+ * measurement_value_size	Size of the measurement_value buffer in bytes.
+ * lock_measurement		Boolean flag requesting whether the measurement
+ *				is to be locked.
+ *
+ * PSA_SUCCESS:
+ *	- Success.
+ * PSA_ERROR_INVALID_ARGUMENT:
+ *	- The size of any argument is invalid OR
+ *	- Input Measurement value is NULL OR
+ *	- Input Signer ID is NULL OR
+ *	- Requested slot index is invalid.
+ * PSA_ERROR_BAD_STATE:
+ *	- Request to lock, when slot is already locked.
+ * PSA_ERROR_NOT_PERMITTED:
+ *	- When the requested slot is not accessible to the caller.
+ */
+
+/* Not a standard PSA API, just an extension therefore use the 'rss_' prefix
+ * rather than the usual 'psa_'.
+ */
+psa_status_t
+rss_measured_boot_extend_measurement(uint8_t index,
+				     const uint8_t *signer_id,
+				     size_t signer_id_size,
+				     const uint8_t *version,
+				     size_t version_size,
+				     uint32_t measurement_algo,
+				     const uint8_t *sw_type,
+				     size_t sw_type_size,
+				     const uint8_t *measurement_value,
+				     size_t measurement_value_size,
+				     bool lock_measurement);
+
+#endif /* PSA_MEASURED_BOOT_H */
diff --git a/include/lib/psa/psa/client.h b/include/lib/psa/psa/client.h
new file mode 100644
index 0000000..56fe028
--- /dev/null
+++ b/include/lib/psa/psa/client.h
@@ -0,0 +1,102 @@
+
+/*
+ * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_CLIENT_H
+#define PSA_CLIENT_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <psa/error.h>
+
+#ifndef IOVEC_LEN
+#define IOVEC_LEN(arr) ((uint32_t)(sizeof(arr)/sizeof(arr[0])))
+#endif
+/*********************** PSA Client Macros and Types *************************/
+/**
+ * The version of the PSA Framework API that is being used to build the calling
+ * firmware. Only part of features of FF-M v1.1 have been implemented. FF-M v1.1
+ * is compatible with v1.0.
+ */
+#define PSA_FRAMEWORK_VERSION	(0x0101u)
+/**
+ * Return value from psa_version() if the requested RoT Service is not present
+ * in the system.
+ */
+#define PSA_VERSION_NONE	(0u)
+/**
+ * The zero-value null handle can be assigned to variables used in clients and
+ * RoT Services, indicating that there is no current connection or message.
+ */
+#define PSA_NULL_HANDLE		((psa_handle_t)0)
+/**
+ * Tests whether a handle value returned by psa_connect() is valid.
+ */
+#define PSA_HANDLE_IS_VALID(handle)	((psa_handle_t)(handle) > 0)
+/**
+ * Converts the handle value returned from a failed call psa_connect() into
+ * an error code.
+ */
+#define PSA_HANDLE_TO_ERROR(handle)	((psa_status_t)(handle))
+/**
+ * Maximum number of input and output vectors for a request to psa_call().
+ */
+#define PSA_MAX_IOVEC		(4u)
+/**
+ * An IPC message type that indicates a generic client request.
+ */
+#define PSA_IPC_CALL		(0)
+typedef int32_t psa_handle_t;
+/**
+ * A read-only input memory region provided to an RoT Service.
+ */
+typedef struct psa_invec {
+	const void *base;	/*!< the start address of the memory buffer */
+	size_t len;		/*!< the size in bytes                      */
+} psa_invec;
+/**
+ * A writable output memory region provided to an RoT Service.
+ */
+typedef struct psa_outvec {
+	void *base;		/*!< the start address of the memory buffer */
+	size_t len;		/*!< the size in bytes                      */
+} psa_outvec;
+
+/**
+ * Call an RoT Service on an established connection.
+ *
+ * handle	A handle to an established connection.
+ * type		The request type. Must be zero(PSA_IPC_CALL) or positive.
+ * in_vec	Array of input psa_invec structures.
+ * in_len	Number of input psa_invec structures.
+ * out_vec	Array of output psa_outvec structures.
+ * out_len	Number of output psa_outvec structures.
+ *
+ * Return value >=0	RoT Service-specific status value.
+ * Return value <0	RoT Service-specific error code.
+ *
+ * PSA_ERROR_PROGRAMMER_ERROR:
+ *	- The connection has been terminated by the RoT Service.
+ *
+ * The call is a PROGRAMMER ERROR if one or more of the following are true:
+ *	- An invalid handle was passed.
+ *	- The connection is already handling a request.
+ *	- type < 0.
+ *	- An invalid memory reference was provided.
+ *	- in_len + out_len > PSA_MAX_IOVEC.
+ *	- The message is unrecognized by the RoT.
+ *	- Service or incorrectly formatted.
+ */
+psa_status_t psa_call(psa_handle_t handle,
+		      int32_t type,
+		      const psa_invec *in_vec,
+		      size_t in_len,
+		      psa_outvec *out_vec,
+		      size_t out_len);
+
+#endif /* PSA_CLIENT_H */
diff --git a/include/lib/psa/psa/error.h b/include/lib/psa/psa/error.h
new file mode 100644
index 0000000..8a6eb7b
--- /dev/null
+++ b/include/lib/psa/psa/error.h
@@ -0,0 +1,42 @@
+
+/*
+ * Copyright (c) 2019-2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_ERROR_H
+#define PSA_ERROR_H
+
+#include <stdint.h>
+
+typedef int32_t psa_status_t;
+
+#define PSA_SUCCESS                     ((psa_status_t)0)
+#define PSA_SUCCESS_REBOOT              ((psa_status_t)1)
+#define PSA_SUCCESS_RESTART             ((psa_status_t)2)
+#define PSA_ERROR_PROGRAMMER_ERROR      ((psa_status_t)-129)
+#define PSA_ERROR_CONNECTION_REFUSED    ((psa_status_t)-130)
+#define PSA_ERROR_CONNECTION_BUSY       ((psa_status_t)-131)
+#define PSA_ERROR_GENERIC_ERROR         ((psa_status_t)-132)
+#define PSA_ERROR_NOT_PERMITTED         ((psa_status_t)-133)
+#define PSA_ERROR_NOT_SUPPORTED         ((psa_status_t)-134)
+#define PSA_ERROR_INVALID_ARGUMENT      ((psa_status_t)-135)
+#define PSA_ERROR_INVALID_HANDLE        ((psa_status_t)-136)
+#define PSA_ERROR_BAD_STATE             ((psa_status_t)-137)
+#define PSA_ERROR_BUFFER_TOO_SMALL      ((psa_status_t)-138)
+#define PSA_ERROR_ALREADY_EXISTS        ((psa_status_t)-139)
+#define PSA_ERROR_DOES_NOT_EXIST        ((psa_status_t)-140)
+#define PSA_ERROR_INSUFFICIENT_MEMORY   ((psa_status_t)-141)
+#define PSA_ERROR_INSUFFICIENT_STORAGE  ((psa_status_t)-142)
+#define PSA_ERROR_INSUFFICIENT_DATA     ((psa_status_t)-143)
+#define PSA_ERROR_SERVICE_FAILURE       ((psa_status_t)-144)
+#define PSA_ERROR_COMMUNICATION_FAILURE ((psa_status_t)-145)
+#define PSA_ERROR_STORAGE_FAILURE       ((psa_status_t)-146)
+#define PSA_ERROR_HARDWARE_FAILURE      ((psa_status_t)-147)
+#define PSA_ERROR_INVALID_SIGNATURE     ((psa_status_t)-149)
+#define PSA_ERROR_DEPENDENCY_NEEDED     ((psa_status_t)-156)
+#define PSA_ERROR_CURRENTLY_INSTALLING  ((psa_status_t)-157)
+
+#endif /* PSA_ERROR_H */
diff --git a/include/lib/psa/psa_manifest/sid.h b/include/lib/psa/psa_manifest/sid.h
new file mode 100644
index 0000000..947e58f
--- /dev/null
+++ b/include/lib/psa/psa_manifest/sid.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2019-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_MANIFEST_SID_H
+#define PSA_MANIFEST_SID_H
+
+/******** PSA_SP_INITIAL_ATTESTATION ********/
+#define RSS_ATTESTATION_SERVICE_SID			(0x00000020U)
+#define RSS_ATTESTATION_SERVICE_VERSION			(1U)
+#define RSS_ATTESTATION_SERVICE_HANDLE			(0x40000103U)
+
+/******** PSA_SP_MEASURED_BOOT ********/
+#define RSS_MEASURED_BOOT_SID				(0x000000E0U)
+#define RSS_MEASURED_BOOT_VERSION			(1U)
+#define RSS_MEASURED_BOOT_HANDLE			(0x40000104U)
+
+#endif /* PSA_MANIFEST_SID_H */
diff --git a/lib/psa/initial_attestation.c b/lib/psa/initial_attestation.c
new file mode 100644
index 0000000..44498a8
--- /dev/null
+++ b/lib/psa/initial_attestation.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2018-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <initial_attestation.h>
+#include <psa/client.h>
+#include <psa_manifest/sid.h>
+
+#if !PLAT_RSS_NOT_SUPPORTED
+psa_status_t
+psa_initial_attest_get_token(const uint8_t *auth_challenge,
+			     size_t         challenge_size,
+			     uint8_t       *token_buf,
+			     size_t         token_buf_size,
+			     size_t        *token_size)
+{
+	psa_status_t status;
+	psa_invec in_vec[] = {
+		{auth_challenge, challenge_size}
+	};
+	psa_outvec out_vec[] = {
+		{token_buf, token_buf_size},
+	};
+
+	status = psa_call(RSS_ATTESTATION_SERVICE_HANDLE, RSS_ATTEST_GET_TOKEN,
+			  in_vec, IOVEC_LEN(in_vec),
+			  out_vec, IOVEC_LEN(out_vec));
+
+	if (status == PSA_SUCCESS) {
+		*token_size = out_vec[0].len;
+	}
+
+	return status;
+}
+
+#else /* !PLAT_RSS_NOT_SUPPORTED */
+
+#include <string.h>
+
+static const uint8_t platform_token[] = {
+	0xD2, 0x84, 0x43, 0xA1, 0x01, 0x26, 0xA0, 0x59,
+	0x02, 0xBE, 0xAA, 0x3A, 0x00, 0x01, 0x24, 0xFF,
+	0x58, 0x20, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
+	0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
+	0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
+	0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
+	0xAB, 0xAB, 0x3A, 0x00, 0x01, 0x24, 0xFB, 0x58,
+	0x20, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6,
+	0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE,
+	0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
+	0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE,
+	0xBF, 0x3A, 0x00, 0x01, 0x25, 0x00, 0x58, 0x21,
+	0x01, 0xFA, 0x58, 0x75, 0x5F, 0x65, 0x86, 0x27,
+	0xCE, 0x54, 0x60, 0xF2, 0x9B, 0x75, 0x29, 0x67,
+	0x13, 0x24, 0x8C, 0xAE, 0x7A, 0xD9, 0xE2, 0x98,
+	0x4B, 0x90, 0x28, 0x0E, 0xFC, 0xBC, 0xB5, 0x02,
+	0x48, 0x3A, 0x00, 0x01, 0x24, 0xFA, 0x58, 0x20,
+	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
+	0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB,
+	0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC,
+	0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD,
+	0x3A, 0x00, 0x01, 0x24, 0xF8, 0x20, 0x3A, 0x00,
+	0x01, 0x24, 0xF9, 0x00, 0x3A, 0x00, 0x01, 0x24,
+	0xFD, 0x85, 0xA5, 0x05, 0x58, 0x20, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x60,
+	0x01, 0x65, 0x42, 0x4C, 0x31, 0x5F, 0x32, 0x06,
+	0x66, 0x53, 0x48, 0x41, 0x32, 0x35, 0x36, 0x02,
+	0x58, 0x20, 0xF8, 0xB7, 0xCE, 0xAD, 0x9B, 0xE4,
+	0x5A, 0x8F, 0x5C, 0x52, 0x6F, 0x0C, 0x05, 0x25,
+	0x8F, 0xF3, 0xE9, 0x81, 0xDC, 0xBC, 0xF2, 0x05,
+	0x7F, 0x33, 0xF6, 0xBB, 0xDC, 0xD9, 0x4D, 0xA2,
+	0x34, 0x3A, 0xA5, 0x05, 0x58, 0x20, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x67,
+	0x31, 0x2E, 0x37, 0x2E, 0x32, 0x2B, 0x30, 0x01,
+	0x63, 0x42, 0x4C, 0x32, 0x06, 0x66, 0x53, 0x48,
+	0x41, 0x32, 0x35, 0x36, 0x02, 0x58, 0x20, 0x3A,
+	0xE5, 0x9E, 0x40, 0xA9, 0x6B, 0xD5, 0x29, 0x1C,
+	0xAB, 0x7A, 0x5F, 0xBD, 0x1F, 0x9A, 0xA6, 0x52,
+	0xFB, 0x77, 0x7D, 0xA3, 0xEC, 0x9C, 0x29, 0xBC,
+	0xE6, 0x5B, 0x3B, 0x43, 0xFC, 0x9D, 0x26, 0xA5,
+	0x05, 0x58, 0x20, 0xBF, 0xE6, 0xD8, 0x6F, 0x88,
+	0x26, 0xF4, 0xFF, 0x97, 0xFB, 0x96, 0xC4, 0xE6,
+	0xFB, 0xC4, 0x99, 0x3E, 0x46, 0x19, 0xFC, 0x56,
+	0x5D, 0xA2, 0x6A, 0xDF, 0x34, 0xC3, 0x29, 0x48,
+	0x9A, 0xDC, 0x38, 0x04, 0x67, 0x31, 0x2E, 0x35,
+	0x2E, 0x30, 0x2B, 0x30, 0x01, 0x64, 0x52, 0x54,
+	0x5F, 0x30, 0x06, 0x66, 0x53, 0x48, 0x41, 0x32,
+	0x35, 0x36, 0x02, 0x58, 0x20, 0x47, 0x94, 0x9D,
+	0x27, 0x33, 0x82, 0x45, 0x1A, 0xDD, 0x25, 0xF4,
+	0x9A, 0x89, 0x6F, 0x5F, 0xD9, 0xB0, 0xE8, 0x14,
+	0xD3, 0xA4, 0x9B, 0x53, 0xB0, 0x44, 0x0B, 0xCF,
+	0x32, 0x1A, 0xC4, 0xD2, 0x65, 0xA5, 0x05, 0x58,
+	0x20, 0xB3, 0x60, 0xCA, 0xF5, 0xC9, 0x8C, 0x6B,
+	0x94, 0x2A, 0x48, 0x82, 0xFA, 0x9D, 0x48, 0x23,
+	0xEF, 0xB1, 0x66, 0xA9, 0xEF, 0x6A, 0x6E, 0x4A,
+	0xA3, 0x7C, 0x19, 0x19, 0xED, 0x1F, 0xCC, 0xC0,
+	0x49, 0x04, 0x67, 0x30, 0x2E, 0x30, 0x2E, 0x37,
+	0x2B, 0x30, 0x01, 0x64, 0x52, 0x54, 0x5F, 0x31,
+	0x06, 0x66, 0x53, 0x48, 0x41, 0x32, 0x35, 0x36,
+	0x02, 0x58, 0x20, 0xCD, 0x38, 0xBE, 0xC8, 0xB7,
+	0xC0, 0x9E, 0xD5, 0x24, 0x30, 0xFE, 0xC8, 0xD0,
+	0x19, 0x12, 0x56, 0xB2, 0x7A, 0xA5, 0x53, 0x6F,
+	0xBC, 0x7D, 0x09, 0xCA, 0x11, 0xDD, 0x90, 0xD7,
+	0xD6, 0x70, 0xFD, 0xA5, 0x05, 0x58, 0x20, 0xAA,
+	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
+	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
+	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
+	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0x04,
+	0x60, 0x01, 0x60, 0x06, 0x66, 0x53, 0x48, 0x41,
+	0x32, 0x35, 0x36, 0x02, 0x58, 0x20, 0x28, 0x3D,
+	0x0C, 0x25, 0x22, 0x0C, 0x87, 0x46, 0xA0, 0x58,
+	0x64, 0x6C, 0x0B, 0x14, 0x37, 0x39, 0x40, 0x9D,
+	0x2D, 0x11, 0xD1, 0xCC, 0x54, 0x51, 0xB4, 0x29,
+	0x22, 0xCD, 0x70, 0x92, 0x71, 0xC3, 0x3A, 0x00,
+	0x01, 0x25, 0x01, 0x77, 0x77, 0x77, 0x77, 0x2E,
+	0x74, 0x72, 0x75, 0x73, 0x74, 0x65, 0x64, 0x66,
+	0x69, 0x72, 0x6D, 0x77, 0x61, 0x72, 0x65, 0x2E,
+	0x6F, 0x72, 0x67, 0x3A, 0x00, 0x01, 0x24, 0xF7,
+	0x71, 0x50, 0x53, 0x41, 0x5F, 0x49, 0x4F, 0x54,
+	0x5F, 0x50, 0x52, 0x4F, 0x46, 0x49, 0x4C, 0x45,
+	0x5F, 0x31, 0x3A, 0x00, 0x01, 0x24, 0xFC, 0x70,
+	0x30, 0x36, 0x30, 0x34, 0x35, 0x36, 0x35, 0x32,
+	0x37, 0x32, 0x38, 0x32, 0x39, 0x31, 0x30, 0x30,
+	0x58, 0x40, 0x1E, 0x0D, 0x2B, 0xD8, 0x7A, 0xC9,
+	0x2D, 0xCB, 0x73, 0xD1, 0x42, 0x2F, 0xBF, 0xDA,
+	0x24, 0x71, 0xE2, 0xAF, 0xEA, 0x48, 0x60, 0x17,
+	0x23, 0x75, 0x64, 0xAC, 0xCC, 0x23, 0xA2, 0x67,
+	0xC4, 0xE7, 0x8F, 0x1C, 0x7C, 0x68, 0x49, 0x42,
+	0x4D, 0xDA, 0xC6, 0xD6, 0x21, 0x1C, 0xAA, 0x00,
+	0xDA, 0x1E, 0x68, 0x56, 0xA3, 0x48, 0xEE, 0xA7,
+	0x92, 0xA9, 0x09, 0x83, 0x42, 0x04, 0x06, 0x9E,
+	0x62, 0xBB
+};
+
+psa_status_t
+psa_initial_attest_get_token(const uint8_t *auth_challenge,
+			     size_t         challenge_size,
+			     uint8_t       *token_buf,
+			     size_t         token_buf_size,
+			     size_t        *token_size)
+{
+	(void)auth_challenge;
+	(void)challenge_size;
+
+	if (token_buf_size < sizeof(platform_token)) {
+		return PSA_ERROR_BUFFER_TOO_SMALL;
+	}
+
+	(void)memcpy(token_buf, platform_token, sizeof(platform_token));
+	*token_size = sizeof(platform_token);
+
+	return PSA_SUCCESS;
+}
+#endif /* !PLAT_RSS_NOT_SUPPORTED */
diff --git a/lib/psa/measured_boot.c b/lib/psa/measured_boot.c
new file mode 100644
index 0000000..5d3ca8e
--- /dev/null
+++ b/lib/psa/measured_boot.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <string.h>
+
+#include <common/debug.h>
+#include <measured_boot.h>
+#include <psa/client.h>
+#include <psa_manifest/sid.h>
+
+#include "measured_boot_private.h"
+
+static void print_byte_array(const uint8_t *array, size_t len)
+{
+	unsigned int i;
+
+	if (array == NULL || len == 0U) {
+		(void)printf("\n");
+	}
+
+	for (i = 0U; i < len; ++i) {
+		(void)printf(" %02x", array[i]);
+		if ((i & U(0xF)) == U(0xF)) {
+			(void)printf("\n");
+			if (i < (len - 1U)) {
+				INFO("\t\t:");
+			}
+		}
+	}
+}
+
+static void log_measurement(uint8_t index,
+			    const uint8_t *signer_id,
+			    size_t signer_id_size,
+			    const uint8_t *version,     /* string */
+			    uint32_t measurement_algo,
+			    const uint8_t *sw_type,     /* string */
+			    const uint8_t *measurement_value,
+			    size_t measurement_value_size,
+			    bool lock_measurement)
+{
+	INFO("Measured boot extend measurement:\n");
+	INFO(" - slot        : %u\n", index);
+	INFO(" - signer_id   :");
+	print_byte_array(signer_id, signer_id_size);
+	INFO(" - version     : %s\n", version);
+	INFO(" - algorithm   : %x\n", measurement_algo);
+	INFO(" - sw_type     : %s\n", sw_type);
+	INFO(" - measurement :");
+	print_byte_array(measurement_value, measurement_value_size);
+	INFO(" - locking     : %s\n", lock_measurement ? "true" : "false");
+}
+
+#if !PLAT_RSS_NOT_SUPPORTED
+psa_status_t
+rss_measured_boot_extend_measurement(uint8_t index,
+				     const uint8_t *signer_id,
+				     size_t signer_id_size,
+				     const uint8_t *version,
+				     size_t version_size,
+				     uint32_t measurement_algo,
+				     const uint8_t *sw_type,
+				     size_t sw_type_size,
+				     const uint8_t *measurement_value,
+				     size_t measurement_value_size,
+				     bool lock_measurement)
+{
+	struct measured_boot_extend_iovec_t extend_iov = {
+		.index = index,
+		.lock_measurement = lock_measurement,
+		.measurement_algo = measurement_algo,
+		.sw_type = {0},
+		.sw_type_size = sw_type_size,
+	};
+
+	psa_invec in_vec[] = {
+		{.base = &extend_iov,
+			.len = sizeof(struct measured_boot_extend_iovec_t)},
+		{.base = signer_id, .len = signer_id_size},
+		{.base = version, .len = version_size},
+		{.base = measurement_value, .len = measurement_value_size}
+	};
+
+	uint32_t sw_type_size_limited;
+
+	if (sw_type != NULL) {
+		sw_type_size_limited = (sw_type_size < SW_TYPE_MAX_SIZE) ?
+					sw_type_size : SW_TYPE_MAX_SIZE;
+		memcpy(extend_iov.sw_type, sw_type, sw_type_size_limited);
+	}
+
+	log_measurement(index, signer_id, signer_id_size,
+			version, measurement_algo, sw_type,
+			measurement_value, measurement_value_size,
+			lock_measurement);
+
+	return psa_call(RSS_MEASURED_BOOT_HANDLE,
+			RSS_MEASURED_BOOT_EXTEND,
+			in_vec, IOVEC_LEN(in_vec),
+			NULL, 0);
+}
+
+#else /* !PLAT_RSS_NOT_SUPPORTED */
+
+psa_status_t
+rss_measured_boot_extend_measurement(uint8_t index,
+				     const uint8_t *signer_id,
+				     size_t signer_id_size,
+				     const uint8_t *version,
+				     size_t version_size,
+				     uint32_t measurement_algo,
+				     const uint8_t *sw_type,
+				     size_t sw_type_size,
+				     const uint8_t *measurement_value,
+				     size_t measurement_value_size,
+				     bool lock_measurement)
+{
+	log_measurement(index, signer_id, signer_id_size,
+			version, measurement_algo, sw_type,
+			measurement_value, measurement_value_size,
+			lock_measurement);
+
+	return PSA_SUCCESS;
+}
+#endif /* !PLAT_RSS_NOT_SUPPORTED */
diff --git a/lib/psa/measured_boot_private.h b/lib/psa/measured_boot_private.h
new file mode 100644
index 0000000..649c3f6
--- /dev/null
+++ b/lib/psa/measured_boot_private.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef PSA_MEASURED_BOOT_PRIVATE_H
+#define PSA_MEASURED_BOOT_PRIVATE_H
+
+#include <stdint.h>
+
+/* Measured boot message types that distinguish its services */
+#define RSS_MEASURED_BOOT_EXTEND	1002U
+
+struct measured_boot_extend_iovec_t {
+	uint8_t  index;
+	uint8_t  lock_measurement;
+	uint32_t measurement_algo;
+	uint8_t  sw_type[SW_TYPE_MAX_SIZE];
+	uint8_t  sw_type_size;
+};
+
+#endif /* PSA_MEASURED_BOOT_PRIVATE_H */
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 6e57237..d5383a1 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -460,3 +460,6 @@
 # SCR_EL3.TWEDEL(4bit) field, when FEAT_TWED is implemented.
 # By default it takes 0, and need to be updated by the platforms.
 TWED_DELAY			:= 0
+
+# By default, disable the mocking of RSS provided services
+PLAT_RSS_NOT_SUPPORTED		:= 0
diff --git a/plat/arm/board/fvp/fvp_bl1_measured_boot.c b/plat/arm/board/fvp/fvp_bl1_measured_boot.c
index 5468555..76cd918 100644
--- a/plat/arm/board/fvp/fvp_bl1_measured_boot.c
+++ b/plat/arm/board/fvp/fvp_bl1_measured_boot.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,7 @@
 #include <stdint.h>
 
 #include <drivers/measured_boot/event_log/event_log.h>
+#include <drivers/measured_boot/rss/rss_measured_boot.h>
 #include <plat/arm/common/plat_arm.h>
 
 /* Event Log data */
@@ -21,10 +22,39 @@
 	{ EVLOG_INVALID_ID, NULL, (unsigned int)(-1) }	/* Terminator */
 };
 
+/* FVP table with platform specific image IDs and metadata. Intentionally not a
+ * const struct, some members might set by bootloaders during trusted boot.
+ */
+struct rss_mboot_metadata fvp_rss_mboot_metadata[] = {
+	{
+		.id = FW_CONFIG_ID,
+		.slot = U(6),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_FW_CONFIG_STRING,
+		.lock_measurement = true },
+	{
+		.id = TB_FW_CONFIG_ID,
+		.slot = U(7),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_TB_FW_CONFIG_STRING,
+		.lock_measurement = true },
+	{
+		.id = BL2_IMAGE_ID,
+		.slot = U(8),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_BL2_STRING,
+		.lock_measurement = true },
+
+	{
+		.id = RSS_MBOOT_INVALID_ID }
+};
+
 void bl1_plat_mboot_init(void)
 {
 	event_log_init(event_log, event_log + sizeof(event_log));
 	event_log_write_header();
+
+	rss_measured_boot_init();
 }
 
 void bl1_plat_mboot_finish(void)
diff --git a/plat/arm/board/fvp/fvp_bl2_measured_boot.c b/plat/arm/board/fvp/fvp_bl2_measured_boot.c
index 1f38278..fd15b70 100644
--- a/plat/arm/board/fvp/fvp_bl2_measured_boot.c
+++ b/plat/arm/board/fvp/fvp_bl2_measured_boot.c
@@ -7,6 +7,7 @@
 #include <stdint.h>
 
 #include <drivers/measured_boot/event_log/event_log.h>
+#include <drivers/measured_boot/rss/rss_measured_boot.h>
 #include <tools_share/tbbr_oid.h>
 #include <fvp_critical_data.h>
 
@@ -35,6 +36,38 @@
 	{ EVLOG_INVALID_ID, NULL, (unsigned int)(-1) }	/* Terminator */
 };
 
+/* FVP table with platform specific image IDs and metadata. Intentionally not a
+ * const struct, some members might set by bootloaders during trusted boot.
+ */
+struct rss_mboot_metadata fvp_rss_mboot_metadata[] = {
+	{
+		.id = BL31_IMAGE_ID,
+		.slot = U(9),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_BL31_STRING,
+		.lock_measurement = true },
+	{
+		.id = HW_CONFIG_ID,
+		.slot = U(10),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_HW_CONFIG_STRING,
+		.lock_measurement = true },
+	{
+		.id = SOC_FW_CONFIG_ID,
+		.slot = U(11),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_SOC_FW_CONFIG_STRING,
+		.lock_measurement = true },
+	{
+		.id = RMM_IMAGE_ID,
+		.slot = U(12),
+		.signer_id_size = SIGNER_ID_MIN_SIZE,
+		.sw_type = RSS_MBOOT_RMM_STRING,
+		.lock_measurement = true },
+	{
+		.id = RSS_MBOOT_INVALID_ID }
+};
+
 void bl2_plat_mboot_init(void)
 {
 	uint8_t *event_log_start;
@@ -64,6 +97,8 @@
 				       PLAT_ARM_EVENT_LOG_MAX_SIZE);
 
 	event_log_init((uint8_t *)event_log_start, event_log_finish);
+
+	rss_measured_boot_init();
 }
 
 int plat_mboot_measure_critical_data(unsigned int critical_data_id,
diff --git a/plat/arm/board/fvp/fvp_common_measured_boot.c b/plat/arm/board/fvp/fvp_common_measured_boot.c
index 6a403d9..93aa055 100644
--- a/plat/arm/board/fvp/fvp_common_measured_boot.c
+++ b/plat/arm/board/fvp/fvp_common_measured_boot.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,27 +9,47 @@
 
 #include <common/desc_image_load.h>
 #include <drivers/measured_boot/event_log/event_log.h>
+#include <drivers/measured_boot/rss/rss_measured_boot.h>
 #include <plat/arm/common/plat_arm.h>
 #include <plat/common/platform.h>
 
 extern event_log_metadata_t fvp_event_log_metadata[];
+extern struct rss_mboot_metadata fvp_rss_mboot_metadata[];
 
 const event_log_metadata_t *plat_event_log_get_metadata(void)
 {
 	return fvp_event_log_metadata;
 }
 
+struct rss_mboot_metadata *plat_rss_mboot_get_metadata(void)
+{
+	return fvp_rss_mboot_metadata;
+}
+
 int plat_mboot_measure_image(unsigned int image_id, image_info_t *image_data)
 {
+	int err;
+	int rc = 0;
+
 	/* Calculate image hash and record data in Event Log */
-	int err = event_log_measure_and_record(image_data->image_base,
-					       image_data->image_size,
-					       image_id);
+	err = event_log_measure_and_record(image_data->image_base,
+					   image_data->image_size,
+					   image_id);
 	if (err != 0) {
 		ERROR("%s%s image id %u (%i)\n",
-		      "Failed to ", "record", image_id, err);
-		return err;
+		      "Failed to ", "record in event log", image_id, err);
+		rc = err;
 	}
 
-	return 0;
+	/* Calculate image hash and record data in RSS */
+	err = rss_mboot_measure_and_record(image_data->image_base,
+					   image_data->image_size,
+					   image_id);
+	if (err != 0) {
+		ERROR("%s%s image id %u (%i)\n",
+		      "Failed to ", "record in RSS", image_id, err);
+		rc = (rc == 0) ? err : -1;
+	}
+
+	return rc;
 }
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index d89e91f..89ca185 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -367,14 +367,36 @@
     override BL1_SOURCES =
 endif
 
+# Include Measured Boot makefile before any Crypto library makefile.
+# Crypto library makefile may need default definitions of Measured Boot build
+# flags present in Measured Boot makefile.
+ifeq (${MEASURED_BOOT},1)
+    RSS_MEASURED_BOOT_MK := drivers/measured_boot/rss/rss_measured_boot.mk
+    $(info Including ${RSS_MEASURED_BOOT_MK})
+    include ${RSS_MEASURED_BOOT_MK}
+
+    BL1_SOURCES		+=	${MEASURED_BOOT_SOURCES}
+    BL2_SOURCES		+=	${MEASURED_BOOT_SOURCES}
+endif
+
 include plat/arm/board/common/board_common.mk
 include plat/arm/common/arm_common.mk
 
 ifeq (${MEASURED_BOOT},1)
 BL1_SOURCES		+=	plat/arm/board/fvp/fvp_common_measured_boot.c	\
-				plat/arm/board/fvp/fvp_bl1_measured_boot.c
+				plat/arm/board/fvp/fvp_bl1_measured_boot.c	\
+				lib/psa/measured_boot.c
+
 BL2_SOURCES		+=	plat/arm/board/fvp/fvp_common_measured_boot.c	\
-				plat/arm/board/fvp/fvp_bl2_measured_boot.c
+				plat/arm/board/fvp/fvp_bl2_measured_boot.c	\
+				lib/psa/measured_boot.c
+
+PLAT_INCLUDES		+=	-Iinclude/lib/psa
+
+# RSS is not supported on FVP right now. Thus, we use the mocked version
+# of PSA Measured Boot APIs. They return with success and hard-coded data.
+PLAT_RSS_NOT_SUPPORTED	:= 1
+
 endif
 
 ifeq (${TRUSTED_BOARD_BOOT}, 1)
diff --git a/plat/arm/css/sgi/sgi-common.mk b/plat/arm/css/sgi/sgi-common.mk
index f56fe35..76c8025 100644
--- a/plat/arm/css/sgi/sgi-common.mk
+++ b/plat/arm/css/sgi/sgi-common.mk
@@ -23,6 +23,8 @@
 # Do not enable SVE
 ENABLE_SVE_FOR_NS		:=	0
 
+CTX_INCLUDE_FPREGS		:=	1
+
 INTERCONNECT_SOURCES	:=	${CSS_ENT_BASE}/sgi_interconnect.c
 
 PLAT_INCLUDES		+=	-I${CSS_ENT_BASE}/include
diff --git a/plat/intel/soc/agilex/include/agilex_noc.h b/plat/intel/soc/agilex/include/agilex_noc.h
deleted file mode 100644
index 9aba3c3..0000000
--- a/plat/intel/soc/agilex/include/agilex_noc.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright (c) 2019-2022, Intel Corporation. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef AGX_NOC_H
-#define AGX_NOC_H
-
-
-#define AXI_AP					(1<<0)
-#define FPGA2SOC				(1<<16)
-#define MPU					(1<<24)
-#define AGX_NOC_PER_SCR_NAND			0xffd21000
-#define AGX_NOC_PER_SCR_NAND_DATA		0xffd21004
-#define AGX_NOC_PER_SCR_USB0			0xffd2100c
-#define AGX_NOC_PER_SCR_USB1			0xffd21010
-#define AGX_NOC_PER_SCR_SPI_M0			0xffd2101c
-#define AGX_NOC_PER_SCR_SPI_M1			0xffd21020
-#define AGX_NOC_PER_SCR_SPI_S0			0xffd21024
-#define AGX_NOC_PER_SCR_SPI_S1			0xffd21028
-#define AGX_NOC_PER_SCR_EMAC0			0xffd2102c
-#define AGX_NOC_PER_SCR_EMAC1			0xffd21030
-#define AGX_NOC_PER_SCR_EMAC2			0xffd21034
-#define AGX_NOC_PER_SCR_SDMMC			0xffd21040
-#define AGX_NOC_PER_SCR_GPIO0			0xffd21044
-#define AGX_NOC_PER_SCR_GPIO1			0xffd21048
-#define AGX_NOC_PER_SCR_I2C0			0xffd21050
-#define AGX_NOC_PER_SCR_I2C1			0xffd21058
-#define AGX_NOC_PER_SCR_I2C2			0xffd2105c
-#define AGX_NOC_PER_SCR_I2C3			0xffd21060
-#define AGX_NOC_PER_SCR_SP_TIMER0		0xffd21064
-#define AGX_NOC_PER_SCR_SP_TIMER1		0xffd21068
-#define AGX_NOC_PER_SCR_UART0			0xffd2106c
-#define AGX_NOC_PER_SCR_UART1			0xffd21070
-
-
-#define AGX_NOC_SYS_SCR_DMA_ECC			0xffd21108
-#define AGX_NOC_SYS_SCR_EMAC0RX_ECC		0xffd2110c
-#define AGX_NOC_SYS_SCR_EMAC0TX_ECC		0xffd21110
-#define AGX_NOC_SYS_SCR_EMAC1RX_ECC		0xffd21114
-#define AGX_NOC_SYS_SCR_EMAC1TX_ECC		0xffd21118
-#define AGX_NOC_SYS_SCR_EMAC2RX_ECC		0xffd2111c
-#define AGX_NOC_SYS_SCR_EMAC2TX_ECC		0xffd21120
-#define AGX_NOC_SYS_SCR_NAND_ECC		0xffd2112c
-#define AGX_NOC_SYS_SCR_NAND_READ_ECC		0xffd21130
-#define AGX_NOC_SYS_SCR_NAND_WRITE_ECC		0xffd21134
-#define AGX_NOC_SYS_SCR_OCRAM_ECC		0xffd21138
-#define AGX_NOC_SYS_SCR_SDMMC_ECC		0xffd21140
-#define AGX_NOC_SYS_SCR_USB0_ECC		0xffd21144
-#define AGX_NOC_SYS_SCR_USB1_ECC		0xffd21148
-#define AGX_NOC_SYS_SCR_CLK_MGR			0xffd2114c
-#define AGX_NOC_SYS_SCR_IO_MGR			0xffd21154
-#define AGX_NOC_SYS_SCR_RST_MGR			0xffd21158
-#define AGX_NOC_SYS_SCR_SYS_MGR			0xffd2115c
-#define AGX_NOC_SYS_SCR_OSC0_TIMER		0xffd21160
-#define AGX_NOC_SYS_SCR_OSC1_TIMER		0xffd21164
-#define AGX_NOC_SYS_SCR_WATCHDOG0		0xffd21168
-#define AGX_NOC_SYS_SCR_WATCHDOG1		0xffd2116c
-#define AGX_NOC_SYS_SCR_WATCHDOG2		0xffd21170
-#define AGX_NOC_SYS_SCR_WATCHDOG3		0xffd21174
-#define AGX_NOC_SYS_SCR_DAP			0xffd21178
-#define AGX_NOC_SYS_SCR_L4_NOC_PROBES		0xffd21190
-#define AGX_NOC_SYS_SCR_L4_NOC_QOS		0xffd21194
-
-#define AGX_CCU_NOC_BRIDGE_CPU0_RAM		0xf7004688
-#define AGX_CCU_NOC_BRIDGE_IOM_RAM		0xf7004688
-
-#endif
diff --git a/plat/intel/soc/common/include/socfpga_sip_svc.h b/plat/intel/soc/common/include/socfpga_sip_svc.h
index f9a6ffd..0803eb5 100644
--- a/plat/intel/soc/common/include/socfpga_sip_svc.h
+++ b/plat/intel/soc/common/include/socfpga_sip_svc.h
@@ -180,6 +180,12 @@
 	int block_number;
 };
 
+typedef enum {
+	NO_REQUEST = 0,
+	RECONFIGURATION,
+	BITSTREAM_AUTH
+} config_type;
+
 /* Function Definitions */
 bool is_size_4_bytes_aligned(uint32_t size);
 bool is_address_in_ddr_range(uint64_t addr, uint64_t size);
diff --git a/plat/intel/soc/common/sip/socfpga_sip_fcs.c b/plat/intel/soc/common/sip/socfpga_sip_fcs.c
index c4e30a2..eacc4dd 100644
--- a/plat/intel/soc/common/sip/socfpga_sip_fcs.c
+++ b/plat/intel/soc/common/sip/socfpga_sip_fcs.c
@@ -315,36 +315,6 @@
 	return INTEL_SIP_SMC_STATUS_OK;
 }
 
-uint32_t intel_fcs_get_rom_patch_sha384(uint64_t addr, uint64_t *ret_size,
-					uint32_t *mbox_error)
-{
-	int status;
-	unsigned int resp_len = FCS_SHA384_WORD_SIZE;
-
-	if (!is_address_in_ddr_range(addr, FCS_SHA384_BYTE_SIZE)) {
-		return INTEL_SIP_SMC_STATUS_REJECTED;
-	}
-
-	status = mailbox_send_cmd(MBOX_JOB_ID, MBOX_GET_ROM_PATCH_SHA384, NULL, 0U,
-			CMD_CASUAL, (uint32_t *) addr, &resp_len);
-
-	if (status < 0) {
-		*mbox_error = -status;
-		return INTEL_SIP_SMC_STATUS_ERROR;
-	}
-
-	if (resp_len != FCS_SHA384_WORD_SIZE) {
-		*mbox_error = GENERIC_RESPONSE_ERROR;
-		return INTEL_SIP_SMC_STATUS_ERROR;
-	}
-
-	*ret_size = FCS_SHA384_BYTE_SIZE;
-
-	flush_dcache_range(addr, *ret_size);
-
-	return INTEL_SIP_SMC_STATUS_OK;
-}
-
 int intel_fcs_encryption_ext(uint32_t session_id, uint32_t context_id,
 		uint32_t src_addr, uint32_t src_size,
 		uint32_t dst_addr, uint32_t *dst_size, uint32_t *mbox_error)
@@ -561,6 +531,36 @@
 	return INTEL_SIP_SMC_STATUS_OK;
 }
 
+uint32_t intel_fcs_get_rom_patch_sha384(uint64_t addr, uint64_t *ret_size,
+					uint32_t *mbox_error)
+{
+	int status;
+	unsigned int resp_len = FCS_SHA384_WORD_SIZE;
+
+	if (!is_address_in_ddr_range(addr, FCS_SHA384_BYTE_SIZE)) {
+		return INTEL_SIP_SMC_STATUS_REJECTED;
+	}
+
+	status = mailbox_send_cmd(MBOX_JOB_ID, MBOX_GET_ROM_PATCH_SHA384, NULL, 0U,
+			CMD_CASUAL, (uint32_t *) addr, &resp_len);
+
+	if (status < 0) {
+		*mbox_error = -status;
+		return INTEL_SIP_SMC_STATUS_ERROR;
+	}
+
+	if (resp_len != FCS_SHA384_WORD_SIZE) {
+		*mbox_error = GENERIC_RESPONSE_ERROR;
+		return INTEL_SIP_SMC_STATUS_ERROR;
+	}
+
+	*ret_size = FCS_SHA384_BYTE_SIZE;
+
+	flush_dcache_range(addr, *ret_size);
+
+	return INTEL_SIP_SMC_STATUS_OK;
+}
+
 int intel_fcs_get_attestation_cert(uint32_t cert_request, uint64_t dst_addr,
 			uint32_t *dst_size, uint32_t *mbox_error)
 {
diff --git a/plat/intel/soc/common/socfpga_delay_timer.c b/plat/intel/soc/common/socfpga_delay_timer.c
index 957738c..dcd51e2 100644
--- a/plat/intel/soc/common/socfpga_delay_timer.c
+++ b/plat/intel/soc/common/socfpga_delay_timer.c
@@ -36,7 +36,6 @@
 
 	timer_init(&plat_timer_ops);
 
-	NOTICE("BL31: MPU clock frequency: %d MHz\n", plat_timer_ops.clk_div);
 }
 
 void socfpga_delay_timer_init(void)
diff --git a/plat/intel/soc/common/socfpga_sip_svc.c b/plat/intel/soc/common/socfpga_sip_svc.c
index f7dd392..f079349 100644
--- a/plat/intel/soc/common/socfpga_sip_svc.c
+++ b/plat/intel/soc/common/socfpga_sip_svc.c
@@ -19,6 +19,7 @@
 /* Total buffer the driver can hold */
 #define FPGA_CONFIG_BUFFER_SIZE 4
 
+static config_type request_type = NO_REQUEST;
 static int current_block, current_buffer;
 static int read_block, max_blocks;
 static uint32_t send_id, rcv_id;
@@ -27,10 +28,8 @@
 
 /* RSU static variables */
 static uint32_t rsu_dcmf_ver[4] = {0};
-
-/* RSU Max Retry */
-static uint32_t rsu_max_retry;
 static uint16_t rsu_dcmf_stat[4] = {0};
+static uint32_t rsu_max_retry;
 
 /*  SiP Service UUID */
 DEFINE_SVC_UUID2(intl_svc_uid,
@@ -89,28 +88,39 @@
 	return 0;
 }
 
-static uint32_t intel_mailbox_fpga_config_isdone(uint32_t query_type)
+static uint32_t intel_mailbox_fpga_config_isdone(void)
 {
 	uint32_t ret;
 
-	if (query_type == 1U) {
-		ret = intel_mailbox_get_config_status(MBOX_CONFIG_STATUS, false);
-	} else {
-		ret = intel_mailbox_get_config_status(MBOX_RECONFIG_STATUS, true);
+	switch (request_type) {
+	case RECONFIGURATION:
+		ret = intel_mailbox_get_config_status(MBOX_RECONFIG_STATUS,
+							true);
+		break;
+	case BITSTREAM_AUTH:
+		ret = intel_mailbox_get_config_status(MBOX_RECONFIG_STATUS,
+							false);
+		break;
+	default:
+		ret = intel_mailbox_get_config_status(MBOX_CONFIG_STATUS,
+							false);
+		break;
 	}
 
 	if (ret != 0U) {
 		if (ret == MBOX_CFGSTAT_STATE_CONFIG) {
 			return INTEL_SIP_SMC_STATUS_BUSY;
 		} else {
+			request_type = NO_REQUEST;
 			return INTEL_SIP_SMC_STATUS_ERROR;
 		}
 	}
 
-	if (bridge_disable) {
+	if (bridge_disable != 0U) {
 		socfpga_bridges_enable(~0);	/* Enable bridge */
 		bridge_disable = false;
 	}
+	request_type = NO_REQUEST;
 
 	return INTEL_SIP_SMC_STATUS_OK;
 }
@@ -169,6 +179,7 @@
 		if (status != MBOX_NO_RESPONSE &&
 			status != MBOX_TIMEOUT && resp_len != 0) {
 			mailbox_clear_response();
+			request_type = NO_REQUEST;
 			return INTEL_SIP_SMC_STATUS_ERROR;
 		}
 
@@ -205,6 +216,8 @@
 	unsigned int size = 0;
 	unsigned int resp_len = ARRAY_SIZE(response);
 
+	request_type = RECONFIGURATION;
+
 	if (!CONFIG_TEST_FLAG(flag, PARTIAL_CONFIG)) {
 		bridge_disable = true;
 	}
@@ -212,6 +225,7 @@
 	if (CONFIG_TEST_FLAG(flag, AUTHENTICATION)) {
 		size = 1;
 		bridge_disable = false;
+		request_type = BITSTREAM_AUTH;
 	}
 
 	mailbox_clear_response();
@@ -224,6 +238,7 @@
 
 	if (status < 0) {
 		bridge_disable = false;
+		request_type = NO_REQUEST;
 		return INTEL_SIP_SMC_STATUS_ERROR;
 	}
 
@@ -644,7 +659,7 @@
 		SMC_UUID_RET(handle, intl_svc_uid);
 
 	case INTEL_SIP_SMC_FPGA_CONFIG_ISDONE:
-		status = intel_mailbox_fpga_config_isdone(x1);
+		status = intel_mailbox_fpga_config_isdone();
 		SMC_RET4(handle, status, 0, 0, 0);
 
 	case INTEL_SIP_SMC_FPGA_CONFIG_GET_MEM:
diff --git a/plat/intel/soc/stratix10/include/s10_noc.h b/plat/intel/soc/stratix10/include/s10_noc.h
deleted file mode 100644
index 3e1e527..0000000
--- a/plat/intel/soc/stratix10/include/s10_noc.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright (c) 2019, Intel Corporation. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#define AXI_AP				(1<<0)
-#define FPGA2SOC			(1<<16)
-#define MPU				(1<<24)
-#define S10_NOC_PER_SCR_NAND		0xffd21000
-#define S10_NOC_PER_SCR_NAND_DATA	0xffd21004
-#define S10_NOC_PER_SCR_USB0		0xffd2100c
-#define S10_NOC_PER_SCR_USB1		0xffd21010
-#define S10_NOC_PER_SCR_SPI_M0		0xffd2101c
-#define S10_NOC_PER_SCR_SPI_M1		0xffd21020
-#define S10_NOC_PER_SCR_SPI_S0		0xffd21024
-#define S10_NOC_PER_SCR_SPI_S1		0xffd21028
-#define S10_NOC_PER_SCR_EMAC0		0xffd2102c
-#define S10_NOC_PER_SCR_EMAC1		0xffd21030
-#define S10_NOC_PER_SCR_EMAC2		0xffd21034
-#define S10_NOC_PER_SCR_SDMMC		0xffd21040
-#define S10_NOC_PER_SCR_GPIO0		0xffd21044
-#define S10_NOC_PER_SCR_GPIO1		0xffd21048
-#define S10_NOC_PER_SCR_I2C0		0xffd21050
-#define S10_NOC_PER_SCR_I2C1		0xffd21058
-#define S10_NOC_PER_SCR_I2C2		0xffd2105c
-#define S10_NOC_PER_SCR_I2C3		0xffd21060
-#define S10_NOC_PER_SCR_SP_TIMER0	0xffd21064
-#define S10_NOC_PER_SCR_SP_TIMER1	0xffd21068
-#define S10_NOC_PER_SCR_UART0		0xffd2106c
-#define S10_NOC_PER_SCR_UART1		0xffd21070
-
-
-#define S10_NOC_SYS_SCR_DMA_ECC			0xffd21108
-#define S10_NOC_SYS_SCR_EMAC0RX_ECC		0xffd2110c
-#define S10_NOC_SYS_SCR_EMAC0TX_ECC		0xffd21110
-#define S10_NOC_SYS_SCR_EMAC1RX_ECC		0xffd21114
-#define S10_NOC_SYS_SCR_EMAC1TX_ECC		0xffd21118
-#define S10_NOC_SYS_SCR_EMAC2RX_ECC		0xffd2111c
-#define S10_NOC_SYS_SCR_EMAC2TX_ECC		0xffd21120
-#define S10_NOC_SYS_SCR_NAND_ECC		0xffd2112c
-#define S10_NOC_SYS_SCR_NAND_READ_ECC		0xffd21130
-#define S10_NOC_SYS_SCR_NAND_WRITE_ECC		0xffd21134
-#define S10_NOC_SYS_SCR_OCRAM_ECC		0xffd21138
-#define S10_NOC_SYS_SCR_SDMMC_ECC		0xffd21140
-#define S10_NOC_SYS_SCR_USB0_ECC		0xffd21144
-#define S10_NOC_SYS_SCR_USB1_ECC		0xffd21148
-#define S10_NOC_SYS_SCR_CLK_MGR			0xffd2114c
-#define S10_NOC_SYS_SCR_IO_MGR			0xffd21154
-#define S10_NOC_SYS_SCR_RST_MGR			0xffd21158
-#define S10_NOC_SYS_SCR_SYS_MGR			0xffd2115c
-#define S10_NOC_SYS_SCR_OSC0_TIMER		0xffd21160
-#define S10_NOC_SYS_SCR_OSC1_TIMER		0xffd21164
-#define S10_NOC_SYS_SCR_WATCHDOG0		0xffd21168
-#define S10_NOC_SYS_SCR_WATCHDOG1		0xffd2116c
-#define S10_NOC_SYS_SCR_WATCHDOG2		0xffd21170
-#define S10_NOC_SYS_SCR_WATCHDOG3		0xffd21174
-#define S10_NOC_SYS_SCR_DAP			0xffd21178
-#define S10_NOC_SYS_SCR_L4_NOC_PROBES		0xffd21190
-#define S10_NOC_SYS_SCR_L4_NOC_QOS		0xffd21194
-
-#define S10_CCU_NOC_BRIDGE_CPU0_RAM		0xf7004688
-#define S10_CCU_NOC_BRIDGE_IOM_RAM		0xf7004688
diff --git a/services/std_svc/spm/spm_mm/spm_mm.mk b/services/std_svc/spm/spm_mm/spm_mm.mk
index 78ef0c9..f6691c3 100644
--- a/services/std_svc/spm/spm_mm/spm_mm.mk
+++ b/services/std_svc/spm/spm_mm/spm_mm.mk
@@ -16,6 +16,9 @@
 ifeq (${ENABLE_SME_FOR_NS},1)
         $(error "Error: SPM_MM is not compatible with ENABLE_SME_FOR_NS")
 endif
+ifeq (${CTX_INCLUDE_FPREGS},0)
+        $(warning "Warning: SPM_MM: CTX_INCLUDE_FPREGS is set to 0")
+endif
 
 SPM_MM_SOURCES	:=	$(addprefix services/std_svc/spm/spm_mm/,	\
 			${ARCH}/spm_mm_shim_exceptions.S		\
diff --git a/services/std_svc/spm/spm_mm/spm_mm_main.c b/services/std_svc/spm/spm_mm/spm_mm_main.c
index e71e65b..8525cd2 100644
--- a/services/std_svc/spm/spm_mm/spm_mm_main.c
+++ b/services/std_svc/spm/spm_mm/spm_mm_main.c
@@ -190,6 +190,14 @@
 	uint64_t rc;
 	sp_context_t *sp_ptr = &sp_ctx;
 
+#if CTX_INCLUDE_FPREGS
+	/*
+	 * SP runs to completion, no need to restore FP registers of secure context.
+	 * Save FP registers only for non secure context.
+	 */
+	fpregs_context_save(get_fpregs_ctx(cm_get_context(NON_SECURE)));
+#endif
+
 	/* Wait until the Secure Partition is idle and set it to busy. */
 	sp_state_wait_switch(sp_ptr, SP_STATE_IDLE, SP_STATE_BUSY);
 
@@ -208,6 +216,14 @@
 	assert(sp_ptr->state == SP_STATE_BUSY);
 	sp_state_set(sp_ptr, SP_STATE_IDLE);
 
+#if CTX_INCLUDE_FPREGS
+	/*
+	 * SP runs to completion, no need to save FP registers of secure context.
+	 * Restore only non secure world FP registers.
+	 */
+	fpregs_context_restore(get_fpregs_ctx(cm_get_context(NON_SECURE)));
+#endif
+
 	return rc;
 }