From 6d26058401bce6012173b5341cdf4de72772a1c2 Mon Sep 17 00:00:00 2001
From: Davidson K <davidson.kumaresan@arm.com>
Date: Mon, 6 Jun 2022 13:19:07 +0530
Subject: [PATCH 5/7] efi_firmware: add new fmp driver that supports arm fwu
 specification

This fmp driver communicates to the firmware update secure partition
executing in the secure world which is an implementation of the arm
psa specification for the firmware update. The communication to the
firmware update secure partition is based on stmm and arm ff-a framework.

It implements only the get_image_info and set_image api.

Signed-off-by: Davidson K <davidson.kumaresan@arm.com>
Change-Id: I94c2cad210c32a60a8a0594cacf530b68ab6a09d
Upstream-Status: Pending [Not submitted to upstream yet]
---
 include/efi_firmware_arm_psa.h        | 218 +++++++++++
 include/efi_loader.h                  |   1 +
 lib/efi_loader/Kconfig                |   9 +
 lib/efi_loader/Makefile               |   1 +
 lib/efi_loader/efi_capsule.c          |   8 +
 lib/efi_loader/efi_firmware.c         | 134 +++++++
 lib/efi_loader/efi_firmware_arm_psa.c | 520 ++++++++++++++++++++++++++
 7 files changed, 891 insertions(+)
 create mode 100644 include/efi_firmware_arm_psa.h
 create mode 100644 lib/efi_loader/efi_firmware_arm_psa.c

diff --git a/include/efi_firmware_arm_psa.h b/include/efi_firmware_arm_psa.h
new file mode 100644
index 0000000000..82f932066c
--- /dev/null
+++ b/include/efi_firmware_arm_psa.h
@@ -0,0 +1,218 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2022 Arm Limited
+ */
+
+#ifndef _EFI_FIRMWARE_ARM_PSA_H
+#define _EFI_FIRMWARE_ARM_PSA_H
+
+#include <efi_loader.h>
+#include <mm_communication.h>
+#include <stdint.h>
+
+#define PSA_FWU_DIRECTORY_UUID \
+	EFI_GUID(0xdeee58d9, 0x5147, 0x4ad3, \
+		 0xa2, 0x90, 0x77, 0x66, 0x6e, 0x23, 0x41, 0xa5)
+
+#define PSA_FWU_SP_UUID \
+	EFI_GUID(0x6823a838, 0x1b06, 0x470e, \
+		 0x97, 0x74, 0x0c, 0xce, 0x8b, 0xfb, 0x53, 0xfd)
+
+#define FFA_FWU_SP_UUID \
+	{0x68, 0x23, 0xa8, 0x38, 0x1b, 0x06, 0x47, \
+		0x0e, 0x97, 0x74, 0x0c, 0xce, 0x8b, 0xfb, 0x53, 0xfd}
+
+#define FWU_DISCOVER		0
+#define FWU_BEGIN_STAGING	1
+#define FWU_END_STAGING 	2
+#define FWU_CANCEL_STAGING	3
+#define FWU_OPEN		4
+#define FWU_WRITE_STREAM	5
+#define FWU_READ_STREAM 	6
+#define FWU_COMMIT		7
+#define FWU_ACCEPT_IMAGE	9
+#define FWU_SELECT_PREVIOUS	10
+
+#define FWU_SUCCESS		0
+#define FWU_UNKNOWN		((int32_t)-1)
+#define FWU_BUSY		((int32_t)-2)
+#define FWU_OUT_OF_BOUNDS	((int32_t)-3)
+#define FWU_AUTH_FAIL		((int32_t)-4)
+#define FWU_NO_PERMISSION	((int32_t)-5)
+#define FWU_DENIED		((int32_t)-6)
+#define FWU_RESUME		((int32_t)-7)
+
+#define MAX_IMAGES		5
+
+typedef int32_t fwu_status_t;
+
+struct fwu_image_info_entry {
+	efi_guid_t image_guid;
+	uint32_t client_permissions;
+	uint32_t img_max_size;
+	uint32_t lowest_acceptable_version;
+	uint32_t img_version;
+	uint32_t accepted;
+	uint32_t reserved;
+}__packed;
+
+struct fwu_image_directory {
+	uint32_t directory_version;
+	uint32_t num_images;
+	uint32_t active_index;
+	uint32_t boot_index;
+	struct fwu_image_info_entry entries[MAX_IMAGES];
+}__packed;
+
+int __efi_runtime arm_psa_get_image_info(
+	efi_uintn_t *image_info_size,
+	struct efi_firmware_image_descriptor *image_info,
+	u32 *descriptor_version,
+	u8 *descriptor_count,
+	efi_uintn_t *descriptor_size,
+	u32 *package_version,
+	u16 **package_version_name
+);
+
+int __efi_runtime arm_psa_update(
+	const void *image,
+	u8 image_index,
+	efi_uintn_t image_size
+);
+
+struct mm_fwu_discover_arg {
+	uint32_t func_id;
+}__packed;
+
+struct mm_fwu_discover_ret {
+	uint32_t status;
+	uint8_t version_major;
+	uint8_t version_minor;
+	uint16_t num_func;
+	uint8_t function_presence[];
+}__packed;
+
+struct mm_fwu_begin_staging_arg {
+	uint32_t func_id;
+}__packed;
+
+struct mm_fwu_begin_staging_ret {
+	uint32_t status;
+}__packed;
+
+struct mm_fwu_end_staging_arg {
+	uint32_t func_id;
+}__packed;
+
+struct mm_fwu_end_staging_ret {
+	uint32_t status;
+}__packed;
+
+struct mm_fwu_cancel_staging_arg {
+	uint32_t func_id;
+}__packed;
+
+struct mm_fwu_cancel_staging_ret {
+	uint32_t status;
+}__packed;
+
+struct mm_fwu_open_arg {
+	uint32_t func_id;
+	efi_guid_t image_guid;
+}__packed;
+
+struct mm_fwu_open_ret {
+	uint32_t status;
+	uint32_t handle;
+}__packed;
+
+struct mm_fwu_write_stream_arg {
+	uint32_t func_id;
+	uint32_t handle;
+	uint32_t data_len;
+	uint8_t payload[];
+}__packed;
+
+struct mm_fwu_write_stream_ret {
+	uint32_t status;
+};
+
+struct mm_fwu_read_stream_arg {
+	uint32_t func_id;
+	uint32_t handle;
+}__packed;
+
+struct mm_fwu_read_stream_ret {
+	uint32_t status;
+	uint32_t read_bytes;
+	uint32_t total_bytes;
+	uint8_t payload[];
+}__packed;
+
+struct mm_fwu_commit_arg {
+	uint32_t func_id;
+	uint32_t handle;
+	uint32_t acceptance_req;
+	uint32_t max_atomic_len;
+}__packed;
+
+struct mm_fwu_commit_ret {
+	uint32_t status;
+	uint32_t progress;
+	uint32_t total_work;
+}__packed;
+
+struct mm_fwu_accept_arg {
+	uint32_t func_id;
+	uint32_t reserved;
+	efi_guid_t image_type_uuid;
+}__packed;
+
+struct mm_fwu_accept_ret {
+	uint32_t status;
+};
+
+struct mm_fwu_select_previous_arg {
+	uint32_t func_id;
+}__packed;
+
+struct mm_fwu_select_previous_ret {
+	uint32_t status;
+}__packed;
+
+inline static void *get_fwu_hdr(struct efi_mm_communicate_header *mm_hdr)
+{
+	const efi_guid_t fwu_sp_guid = PSA_FWU_SP_UUID;
+	guidcpy(&mm_hdr->header_guid, &fwu_sp_guid);
+	return mm_hdr->data;
+}
+
+#define GET_HDR(name)						\
+static inline struct mm_fwu_##name *				\
+get_fwu_##name (struct efi_mm_communicate_header *mm_hdr)	\
+{								\
+	return (struct mm_fwu_##name *)get_fwu_hdr(mm_hdr);	\
+}								\
+
+GET_HDR(discover_arg)
+GET_HDR(discover_ret)
+GET_HDR(begin_staging_arg)
+GET_HDR(begin_staging_ret)
+GET_HDR(end_staging_arg)
+GET_HDR(end_staging_ret)
+GET_HDR(cancel_staging_arg)
+GET_HDR(cancel_staging_ret)
+GET_HDR(open_arg)
+GET_HDR(open_ret)
+GET_HDR(write_stream_arg)
+GET_HDR(write_stream_ret)
+GET_HDR(read_stream_arg)
+GET_HDR(read_stream_ret)
+GET_HDR(commit_arg)
+GET_HDR(commit_ret)
+GET_HDR(accept_arg)
+GET_HDR(accept_ret)
+GET_HDR(select_previous_arg)
+GET_HDR(select_previous_ret)
+
+#endif /* _EFI_FIRMWARE_ARM_PSA_H */
diff --git a/include/efi_loader.h b/include/efi_loader.h
index af36639ec6..7327c87497 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -961,6 +961,7 @@ u16 *efi_create_indexed_name(u16 *buffer, size_t buffer_size, const char *name,
 
 extern const struct efi_firmware_management_protocol efi_fmp_fit;
 extern const struct efi_firmware_management_protocol efi_fmp_raw;
+extern const struct efi_firmware_management_protocol efi_fmp_arm_psa;
 
 /* Capsule update */
 efi_status_t EFIAPI efi_update_capsule(
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index e5e35fe51f..f99d436f16 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -168,6 +168,15 @@ config EFI_CAPSULE_FIRMWARE_MANAGEMENT
 	  Select this option if you want to enable capsule-based
 	  firmware update using Firmware Management Protocol.
 
+config EFI_CAPSULE_FIRMWARE_ARM_PSA
+	bool "FMP driver for ARM PSA FWU specification"
+	depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT
+	select EFI_CAPSULE_FIRMWARE
+	help
+	  Select this option if you want to enable firmware management protocol
+	  driver that supports the ARM PSA firmware update specification as
+	  mentioned in https://developer.arm.com/documentation/den0118/a/
+
 config EFI_CAPSULE_FIRMWARE_FIT
 	bool "FMP driver for FIT images"
 	depends on FIT
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index 034d26cf01..f986ac6417 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -38,6 +38,7 @@ obj-y += efi_boottime.o
 obj-y += efi_helper.o
 obj-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += efi_capsule.o
 obj-$(CONFIG_EFI_CAPSULE_FIRMWARE) += efi_firmware.o
+obj-$(CONFIG_EFI_CAPSULE_FIRMWARE_ARM_PSA) += efi_firmware_arm_psa.o
 obj-y += efi_console.o
 obj-y += efi_device_path.o
 obj-$(CONFIG_EFI_DEVICE_PATH_TO_TEXT) += efi_device_path_to_text.o
diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index f00440163d..3154fc51d3 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -1041,6 +1041,14 @@ efi_status_t __weak efi_load_capsule_drivers(void)
 				&efi_fmp_raw, NULL));
 	}
 
+	if (IS_ENABLED(CONFIG_EFI_CAPSULE_FIRMWARE_ARM_PSA)) {
+		handle = NULL;
+		ret = EFI_CALL(efi_install_multiple_protocol_interfaces(
+				&handle,
+				&efi_guid_firmware_management_protocol,
+				&efi_fmp_arm_psa, NULL));
+	}
+
 	return ret;
 }
 
diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
index a5ff32f121..3356559af8 100644
--- a/lib/efi_loader/efi_firmware.c
+++ b/lib/efi_loader/efi_firmware.c
@@ -9,6 +9,7 @@
 #include <common.h>
 #include <charset.h>
 #include <dfu.h>
+#include <efi_firmware_arm_psa.h>
 #include <efi_loader.h>
 #include <image.h>
 #include <signatures.h>
@@ -478,3 +479,136 @@ const struct efi_firmware_management_protocol efi_fmp_raw = {
 	.set_package_info = efi_firmware_set_package_info_unsupported,
 };
 #endif /* CONFIG_EFI_CAPSULE_FIRMWARE_RAW */
+
+#ifdef CONFIG_EFI_CAPSULE_FIRMWARE_ARM_PSA
+/*
+ * This FIRMWARE_MANAGEMENT_PROTOCOL driver provides a firmware update
+ * method that supports the arm psa firmware update specification.
+ */
+
+/**
+ * efi_firmware_arm_psa_get_image_info - return information about the
+ * 					 current firmware image
+ * @this:			Protocol instance
+ * @image_info_size:		Size of @image_info
+ * @image_info:			Image information
+ * @descriptor_version:		Pointer to version number
+ * @descriptor_count:		Pointer to number of descriptors
+ * @descriptor_size:		Pointer to descriptor size
+ * package_version:		Package version
+ * package_version_name:	Package version's name
+ *
+ * Return information bout the current firmware image in @image_info.
+ * @image_info will consist of a number of descriptors.
+ *
+ * Return		status code
+ */
+
+static
+efi_status_t EFIAPI efi_firmware_arm_psa_get_image_info(
+	struct efi_firmware_management_protocol *this,
+	efi_uintn_t *image_info_size,
+	struct efi_firmware_image_descriptor *image_info,
+	u32 *descriptor_version,
+	u8 *descriptor_count,
+	efi_uintn_t *descriptor_size,
+	u32 *package_version,
+	u16 **package_version_name)
+{
+	int ret;
+
+	EFI_ENTRY("%p %p %p %p %p %p %p %p\n", this,
+		  image_info_size, image_info,
+		  descriptor_version, descriptor_count, descriptor_size,
+		  package_version, package_version_name);
+
+	if (!image_info_size)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	if (*image_info_size &&
+	    (!image_info || !descriptor_version || !descriptor_count ||
+	     !descriptor_size || !package_version || !package_version_name))
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	ret = arm_psa_get_image_info(image_info_size, image_info,
+				descriptor_version, descriptor_count,
+				descriptor_size,
+				package_version, package_version_name);
+
+	if (ret) {
+		if (ret == -ENOMEM)
+			return EFI_EXIT(EFI_BUFFER_TOO_SMALL);
+		else
+			return EFI_EXIT(EFI_DEVICE_ERROR);
+	}
+
+	return EFI_EXIT(EFI_SUCCESS);
+}
+
+/**
+ * efi_firmware_arm_psa_set_image - update the firmware image
+ * @this:		Protocol instance
+ * @image_index:	Image index number
+ * @image:		New image
+ * @image_size:		Size of new image
+ * @vendor_code:	Vendor-specific update policy
+ * @progress:		Function to report the progress of update
+ * @abort_reason:	Pointer to string of abort reason
+ *
+ * Update the firmware to new image, following the arm psa firmware
+ * update specification.
+ * @vendor_code, @progress and @abort_reason are not supported.
+ *
+ * Return:		status code
+ */
+static
+efi_status_t EFIAPI efi_firmware_arm_psa_set_image(
+	struct efi_firmware_management_protocol *this,
+	u8 image_index,
+	const void *image,
+	efi_uintn_t image_size,
+	const void *vendor_code,
+	efi_status_t (*progress)(efi_uintn_t completion),
+	u16 **abort_reason)
+{
+	u32 fmp_hdr_signature;
+	const struct fmp_payload_header *header;
+
+	EFI_ENTRY("%p %d %p %zd %p %p %p\n", this, image_index, image,
+		  image_size, vendor_code, progress, abort_reason);
+
+	if (!image)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	/* TODO: capsule authentication */
+
+	fmp_hdr_signature = FMP_PAYLOAD_HDR_SIGNATURE;
+	header = (void *)image;
+
+	if (!memcmp(&header->signature, &fmp_hdr_signature,
+		    sizeof(fmp_hdr_signature))) {
+		/*
+		 * When building the capsule with the scripts in
+		 * edk2, a FMP header is inserted above the capsule
+		 * payload. Compensate for this header to get the
+		 * actual payload that is to be updated.
+		 */
+		image = (unsigned char *)image + header->header_size;
+		image_size -= header->header_size;
+	}
+
+	if (arm_psa_update(image, image_index, image_size))
+		return EFI_EXIT(EFI_DEVICE_ERROR);
+
+	return EFI_EXIT(EFI_SUCCESS);
+}
+
+const struct efi_firmware_management_protocol efi_fmp_arm_psa = {
+	.get_image_info = efi_firmware_arm_psa_get_image_info,
+	.get_image = efi_firmware_get_image_unsupported,
+	.set_image = efi_firmware_arm_psa_set_image,
+	.check_image = efi_firmware_check_image_unsupported,
+	.get_package_info = efi_firmware_get_package_info_unsupported,
+	.set_package_info = efi_firmware_set_package_info_unsupported,
+};
+#endif /* CONFIG_EFI_CAPSULE_FIRMWARE_ARM_PSA */
diff --git a/lib/efi_loader/efi_firmware_arm_psa.c b/lib/efi_loader/efi_firmware_arm_psa.c
new file mode 100644
index 0000000000..ab575f0124
--- /dev/null
+++ b/lib/efi_loader/efi_firmware_arm_psa.c
@@ -0,0 +1,520 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2022 Arm Limited
+ */
+
+#include <arm_ffa_helper.h>
+#include <configs/total_compute.h>
+#include <efi_firmware_arm_psa.h>
+#include <efi_loader.h>
+#include <malloc.h>
+#include <mapmem.h>
+#include <mm_communication.h>
+
+/* MM return codes */
+#define MM_SUCCESS	0
+
+#define ARM_SVC_ID_SP_EVENT_COMPLETE_AARCH64	0xC4000061
+#define ARM_SVC_ID_SP_EVENT_COMPLETE		ARM_SVC_ID_SP_EVENT_COMPLETE_AARCH64
+
+__efi_runtime_data static u16 mm_sp_id;
+__efi_runtime_data static int fwu_initialized = 0;
+__efi_runtime_data struct fwu_image_directory cached_image_directory;
+__efi_runtime_data struct efi_mm_communicate_header *mm_hdr;
+__efi_runtime_data void *mm_comm_buf;
+
+/**
+ * ffa_discover_mm_sp_id() - Query the MM partition ID
+ *
+ * Use the FF-A driver to get the MM partition ID.
+ * If multiple partitions are found, use the first one
+ *
+ * Return:
+ *
+ * 0 on success
+ */
+static int __efi_runtime ffa_discover_mm_sp_id(void)
+{
+	struct ffa_interface_data func_data = {0};
+	u32 count = 0;
+	int ret;
+	struct ffa_partition_info *parts_info;
+	static union ffa_partition_uuid fwu_sp_uuid = {.bytes = FFA_FWU_SP_UUID};
+
+	/*
+	 * get from the driver the count of the SPs matching the UUID
+	 */
+	func_data.data0_size = sizeof(fwu_sp_uuid);
+	func_data.data0 = &fwu_sp_uuid;
+	func_data.data1_size = sizeof(count);
+	func_data.data1 = &count;
+
+	ret = ffa_helper_get_partitions_info(&func_data);
+	if (ret != FFA_ERR_STAT_SUCCESS) {
+		log_err("EFI: Failure in querying partitions count (error code: %d)\n", ret);
+		return ret;
+	}
+
+	if (!count) {
+		log_info("EFI: No MM partition found\n");
+		return ret;
+	}
+
+	/*
+	 * pre-allocate a buffer to be filled by the driver
+	 * with  ffa_partition_info structs
+	 */
+	parts_info = calloc(count, sizeof(struct ffa_partition_info));
+	if (!parts_info)
+		return -EINVAL;
+
+	log_info("EFI: Pre-allocating %d partition(s) info structures\n", count);
+
+	func_data.data1_size = count * sizeof(struct ffa_partition_info);
+	func_data.data1 = parts_info;
+
+	/*
+	 * ask the driver to fill the
+	 * buffer with the SPs info
+	 */
+	ret = ffa_helper_get_partitions_info(&func_data);
+	if (ret != FFA_ERR_STAT_SUCCESS) {
+		log_err("EFI: Failure in querying partition(s) info (error code: %d)\n", ret);
+		free(parts_info);
+		return ret;
+	}
+
+	/*
+	 * MM SPs found , use the first one
+	 */
+
+	mm_sp_id = parts_info[0].id;
+
+	log_info("EFI: MM partition ID 0x%x\n", mm_sp_id);
+
+	free(parts_info);
+
+	return 0;
+}
+
+/**
+ * ffa_notify_mm_sp() - Announce there is data in the shared buffer
+ *
+ * Notifies the MM partition in the trusted world that
+ * data is available in the shared buffer.
+ * This is a blocking call during which trusted world has exclusive access
+ * to the MM shared buffer.
+ *
+ * Return:
+ *
+ * 0 on success
+ */
+static int __efi_runtime ffa_notify_mm_sp(void)
+{
+	struct ffa_interface_data func_data = {0};
+	struct ffa_send_direct_data msg = {0};
+	int ret;
+	u32 sp_event_complete;
+	int sp_event_ret;
+
+	func_data.data0_size = sizeof(mm_sp_id);
+	func_data.data0 = &mm_sp_id;
+
+	msg.a3 = FFA_SHARED_MM_BUFFER_ADDR;
+	msg.a4 = FFA_SHARED_MM_BUFFER_SIZE;
+	func_data.data1_size = sizeof(msg);
+	func_data.data1 = &msg;
+
+	ret = ffa_helper_msg_send_direct_req(&func_data);
+	if (ret != FFA_ERR_STAT_SUCCESS) {
+		log_err("EFI: Failure to notify the MM SP , FF-A  error (%d)\n", ret);
+		return ret;
+	}
+
+	sp_event_complete = msg.a3;
+	sp_event_ret = (int)msg.a4;
+
+	if (sp_event_complete == ARM_SVC_ID_SP_EVENT_COMPLETE && sp_event_ret == MM_SUCCESS)
+		return 0;
+
+	log_err("EFI: Failure to notify the MM SP (0x%x , %d)\n",
+		sp_event_complete,
+		sp_event_ret);
+
+	return -EACCES;
+}
+
+static fwu_status_t __efi_runtime fwu_discover(void)
+{
+	int ret;
+	struct mm_fwu_discover_arg *discover_arg = get_fwu_discover_arg(mm_hdr);
+	struct mm_fwu_discover_ret *discover_ret = get_fwu_discover_ret(mm_hdr);
+
+	discover_arg->func_id = FWU_DISCOVER;
+
+	mm_hdr->message_len = sizeof(struct mm_fwu_discover_arg);
+
+	ret = ffa_notify_mm_sp();
+	if (ret)
+		return ret;
+
+	if (discover_ret->version_major != 1) {
+		log_err("FWU: Unsupported Update Agent version\n");
+		return -EINVAL;
+	}
+	/* TODO: check other parameters as well */
+
+	return discover_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_begin_staging(void)
+{
+	int ret;
+	struct mm_fwu_begin_staging_arg *begin_staging_arg = get_fwu_begin_staging_arg(mm_hdr);
+	struct mm_fwu_begin_staging_ret *begin_staging_ret = get_fwu_begin_staging_ret(mm_hdr);
+
+	begin_staging_arg->func_id = FWU_BEGIN_STAGING;
+
+	mm_hdr->message_len = sizeof(struct mm_fwu_begin_staging_arg);
+
+	ret = ffa_notify_mm_sp();
+	if (ret)
+		return ret;
+
+	return begin_staging_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_end_staging(void)
+{
+	int ret;
+	struct mm_fwu_end_staging_arg *end_staging_arg = get_fwu_end_staging_arg(mm_hdr);
+	struct mm_fwu_end_staging_ret *end_staging_ret = get_fwu_end_staging_ret(mm_hdr);
+
+	end_staging_arg->func_id = FWU_END_STAGING;
+
+	mm_hdr->message_len = sizeof(struct mm_fwu_end_staging_arg);
+
+	ret = ffa_notify_mm_sp();
+	if (ret)
+		return ret;
+
+	return end_staging_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_cancel_staging(void)
+{
+	int ret;
+	struct mm_fwu_cancel_staging_arg *cancel_staging_arg = get_fwu_cancel_staging_arg(mm_hdr);
+	struct mm_fwu_cancel_staging_ret *cancel_staging_ret = get_fwu_cancel_staging_ret(mm_hdr);
+
+	cancel_staging_arg->func_id = FWU_CANCEL_STAGING;
+
+	mm_hdr->message_len = sizeof(struct mm_fwu_cancel_staging_arg);
+
+	ret = ffa_notify_mm_sp();
+	if (ret)
+		return ret;
+
+	return cancel_staging_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_open(const efi_guid_t *img_uuid, uint32_t *handle)
+{
+	int ret;
+	struct mm_fwu_open_arg *open_hdr = get_fwu_open_arg(mm_hdr);
+	struct mm_fwu_open_ret *open_ret = get_fwu_open_ret(mm_hdr);
+
+	open_hdr->func_id = FWU_OPEN;
+	guidcpy(&open_hdr->image_guid, img_uuid);
+
+	mm_hdr->message_len = sizeof(struct mm_fwu_open_arg);
+
+	ret = ffa_notify_mm_sp();
+	if (ret)
+		return ret;
+
+	*handle = open_ret->handle;
+
+	return open_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_read_stream(uint32_t handle, uint8_t *buffer, uint32_t buffer_size)
+{
+	int ret;
+	struct mm_fwu_read_stream_arg *read_stream_hdr = get_fwu_read_stream_arg(mm_hdr);
+	struct mm_fwu_read_stream_ret *read_stream_ret = get_fwu_read_stream_ret(mm_hdr);
+	uint32_t payload_size = FFA_SHARED_MM_BUFFER_SIZE - sizeof(struct mm_fwu_read_stream_ret)
+							- sizeof(struct efi_mm_communicate_header);
+	uint32_t read_offset = 0, read_size, total_size;
+
+	do {
+		read_stream_hdr->func_id = FWU_READ_STREAM;
+		read_stream_hdr->handle = handle;
+
+		mm_hdr->message_len = sizeof(struct mm_fwu_read_stream_arg);
+
+		ret = ffa_notify_mm_sp();
+		if (ret)
+			return ret;
+
+		if (read_stream_ret->status)
+			return read_stream_ret->status;
+
+		read_size = read_stream_ret->read_bytes;
+		total_size = read_stream_ret->total_bytes;
+
+		log_info("FWU: read bytes / total bytes : %d/%d\n", read_size, total_size);
+
+		if ((read_size <= payload_size) && (read_offset + read_size <= buffer_size))
+			memcpy(buffer + read_offset, read_stream_ret->payload, read_size);
+		else
+			return -EINVAL;
+
+		read_offset += read_size;
+
+		if (read_offset > total_size)
+			return -EINVAL;
+	} while (total_size != read_offset);
+
+	return read_stream_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_write_stream(uint32_t handle, const uint8_t *buffer, uint32_t remaining_size)
+{
+	int ret;
+	struct mm_fwu_write_stream_arg *write_stream_arg = get_fwu_write_stream_arg(mm_hdr);
+	struct mm_fwu_write_stream_ret *write_stream_ret = get_fwu_write_stream_ret(mm_hdr);
+	uint32_t write_size;
+	uint32_t payload_size = FFA_SHARED_MM_BUFFER_SIZE - sizeof(struct mm_fwu_write_stream_arg)
+							- sizeof(struct efi_mm_communicate_header);
+
+	while (remaining_size) {
+		write_size = (remaining_size < payload_size) ? remaining_size :  payload_size;
+		write_stream_arg->func_id = FWU_WRITE_STREAM;
+		write_stream_arg->handle = handle;
+		write_stream_arg->data_len = write_size;
+		memcpy(write_stream_arg->payload, buffer, write_size);
+
+		mm_hdr->message_len = sizeof(struct mm_fwu_write_stream_arg) + write_size;
+
+		ret = ffa_notify_mm_sp();
+		if (ret)
+			return ret;
+
+		if(write_stream_ret->status)
+			return write_stream_ret->status;
+
+		remaining_size -= write_size;
+		buffer += write_size;
+
+		log_info("FWU: write size = %d, remaining size = %d\n",
+				write_size, remaining_size);
+	}
+
+	return write_stream_ret->status;
+}
+
+static fwu_status_t __efi_runtime fwu_commit(uint32_t handle, bool client_accept)
+{
+	int ret;
+	struct mm_fwu_commit_arg *commit_arg = get_fwu_commit_arg(mm_hdr);
+	struct mm_fwu_commit_ret *commit_ret = get_fwu_commit_ret(mm_hdr);
+
+	do {
+		commit_arg->func_id = FWU_COMMIT;
+		commit_arg->handle = handle;
+		commit_arg->acceptance_req = client_accept;
+		commit_arg->max_atomic_len = 0;
+
+		mm_hdr->message_len = sizeof(struct mm_fwu_commit_arg);
+
+		ret = ffa_notify_mm_sp();
+		if (ret)
+			return ret;
+
+		log_info("FWU: commit progress %d/%d (work/total_work)\n",
+			commit_ret->progress, commit_ret->total_work);
+
+	} while(commit_ret->status==FWU_RESUME);
+
+	return commit_ret->status;
+}
+
+int __efi_runtime arm_psa_update(
+	const void *image,
+	u8 image_index,
+	efi_uintn_t image_size
+)
+{
+	int ret = 0;
+	uint32_t handle;
+
+	if(image_index >= cached_image_directory.num_images)
+		return -EINVAL;
+
+	ret = fwu_begin_staging();
+	if (ret) {
+		log_err("FWU: begin staging failed, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = fwu_open(&cached_image_directory.entries[image_index].image_guid, &handle);
+	if (ret) {
+		log_err("FWU: firmware image open failed, ret = %d\n", ret);
+		goto cancel_staging;
+	}
+
+	ret = fwu_write_stream(handle, (uint8_t *)image, image_size);
+	if (ret) {
+		log_err("FWU: write stream failed, ret = %d\n", ret);
+		goto cancel_staging;
+	}
+
+	/* TODO: implement client driven image acceptance */
+	ret = fwu_commit(handle, 0);
+	if (ret) {
+		log_err("FWU: commit failed, ret = %d\n", ret);
+		goto cancel_staging;
+	}
+
+	ret = fwu_end_staging();
+	if (ret) {
+		log_err("FWU: end staging failed, ret = %d\n", ret);
+		goto cancel_staging;
+	}
+
+	log_info("successfully updated the image at index %d\n", image_index);
+	return ret;
+
+cancel_staging:
+	if (fwu_cancel_staging())
+		log_err("FWU: cancel staging failed, ret = %d\n", ret);
+
+	return ret;
+}
+
+static int __efi_runtime read_image_directory(void)
+{
+	int ret;
+	uint32_t handle;
+
+	const efi_guid_t fwu_directory_uuid = PSA_FWU_DIRECTORY_UUID;
+
+	ret = fwu_open(&fwu_directory_uuid, &handle);
+	if (ret) {
+		log_err("FWU: open image directory failed, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = fwu_read_stream(handle, (uint8_t *)&cached_image_directory, sizeof(cached_image_directory));
+	if (ret) {
+		log_err("FWU: read stream failed, ret = %d\n", ret);
+		return ret;
+	}
+
+	if(cached_image_directory.num_images > MAX_IMAGES) {
+		log_err("FWU: image limit exceeded.\n");
+		log_err("FWU: number of images present: %d, max number of images supported: %d\n",
+					cached_image_directory.num_images, MAX_IMAGES);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int update_agent_init(void)
+{
+	int ret;
+
+	ret = ffa_discover_mm_sp_id();
+	if (ret) {
+		log_err("FWU: discover update agent failed, ret = %d\n", ret);
+		return ret;
+	}
+
+	mm_comm_buf = (void *)map_sysmem((phys_addr_t)FFA_SHARED_MM_BUFFER_ADDR, 0);
+	mm_hdr = (struct efi_mm_communicate_header *)mm_comm_buf;
+
+	ret = fwu_discover();
+	if (ret) {
+		log_err("FWU: discover failed, ret = %d\n", ret);
+		goto out;
+	}
+
+	ret = read_image_directory();
+	if (ret) {
+		log_err("FWU: reading image directory failed, ret = %d\n", ret);
+		goto out;
+	}
+
+	fwu_initialized = 1;
+	return ret;
+out:
+	unmap_sysmem(mm_comm_buf);
+	return ret;
+}
+
+int __efi_runtime arm_psa_get_image_info(
+        efi_uintn_t *image_info_size,
+        struct efi_firmware_image_descriptor *image_info,
+        u32 *descriptor_version,
+        u8 *descriptor_count,
+        efi_uintn_t *descriptor_size,
+        u32 *package_version,
+        u16 **package_version_name)
+{
+	int ret = 0;
+	int required_image_info_size;
+
+	if (!fwu_initialized) {
+		ret = update_agent_init();
+		if (ret) {
+			log_err("update agent init failed, ret = %d\n", ret);
+			return ret;
+		}
+	}
+
+	required_image_info_size = cached_image_directory.num_images *
+				sizeof(struct efi_firmware_image_descriptor);
+
+	if (*image_info_size < required_image_info_size) {
+		*image_info_size = required_image_info_size;
+		return -ENOMEM;
+	}
+
+	*descriptor_version = EFI_FIRMWARE_IMAGE_DESCRIPTOR_VERSION;
+	*descriptor_count = cached_image_directory.num_images;
+	*descriptor_size = required_image_info_size;
+	*package_version = 0xffffffff; /* not supported */
+	*package_version_name = NULL; /* not supported */
+
+	for (int i = 0; i < cached_image_directory.num_images; i++) {
+		image_info[i].image_index = i+1;
+		guidcpy(&image_info[i].image_type_id, &cached_image_directory.entries[i].image_guid);
+		image_info[i].image_id = i;
+		image_info[i].image_id_name = NULL; /* not supported */
+		image_info[i].version = cached_image_directory.entries[i].img_version;
+		image_info[i].version_name = NULL; /* not supported */
+		image_info[i].size = cached_image_directory.entries[i].img_max_size;
+
+		image_info[i].attributes_supported =
+			IMAGE_ATTRIBUTE_IMAGE_UPDATABLE |
+			IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED;
+		image_info[i].attributes_setting =
+				IMAGE_ATTRIBUTE_IMAGE_UPDATABLE;
+
+		/* Check if the capsule authentication is enabled */
+		if (IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE))
+			image_info[i].attributes_setting |=
+				IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED;
+
+		image_info[i].lowest_supported_image_version =
+			cached_image_directory.entries[i].lowest_acceptable_version;
+		image_info[i].last_attempt_version = 0;
+		image_info[i].last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
+		image_info[i].hardware_instance = 1;
+		image_info[i].dependencies = NULL; /* not supported */
+	}
+
+	return ret;
+}
-- 
2.34.1