Add Firmware Image Package (FIP) driver

The Firmware Image Package (FIP) driver allows for data to be loaded
from a FIP on platform storage. The FVP supports loading bootloader
images from a FIP located in NOR FLASH.

The implemented FVP policy states that bootloader images will be
loaded from a FIP in NOR FLASH if available and fall back to loading
individual images from semi-hosting.

NOTE:
- BL3-3(e.g. UEFI) is loaded into DRAM and needs to be configured
  to run from the BL33_BASE address. This is currently set to
  DRAM_BASE+128MB for the FVP.

Change-Id: I2e4821748e3376b5f9e467cf3ec09509e43579a0

4 files changed, 721 insertions, 0 deletions

diff --git a/drivers/io/io_fip.c b/drivers/io/io_fip.c
new file mode 100644
index 0000000..6a7f123
--- /dev/null
+++ b/drivers/io/io_fip.c
@@ -0,0 +1,409 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <uuid.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include "platform.h"
+#include "firmware_image_package.h"
+#include "io_storage.h"
+#include "io_driver.h"
+#include "io_fip.h"
+#include "debug.h"
+
+/* Useful for printing UUIDs when debugging.*/
+#define PRINT_UUID2(x)								\
+	"%08x-%04hx-%04hx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx",	\
+		x.time_low, x.time_mid, x.time_hi_and_version,			\
+		x.clock_seq_hi_and_reserved, x.clock_seq_low,			\
+		x.node[0], x.node[1], x.node[2], x.node[3],			\
+		x.node[4], x.node[5]
+
+typedef struct {
+	const char	*name;
+	const uuid_t	 uuid;
+} plat_fip_name_uuid;
+
+typedef struct {
+	/* Put file_pos above the struct to allow {0} on static init.
+	 * It is a workaround for a known bug in GCC
+	 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119
+	 */
+	unsigned int file_pos;
+	fip_toc_entry entry;
+} file_state;
+
+static plat_fip_name_uuid name_uuid[] = {
+	{BL2_IMAGE_NAME, UUID_TRUSTED_BOOT_FIRMWARE_BL2},
+	{BL31_IMAGE_NAME, UUID_EL3_RUNTIME_FIRMWARE_BL31},
+	{BL32_IMAGE_NAME, UUID_SECURE_PAYLOAD_BL32},
+	{BL33_IMAGE_NAME, UUID_NON_TRUSTED_FIRMWARE_BL33},
+	{NULL, {0} }
+};
+
+static const uuid_t uuid_null = {0};
+static file_state current_file = {0};
+static io_dev_handle backend_dev_handle;
+static void *backend_image_spec;
+
+
+/* Firmware Image Package driver functions */
+static int fip_dev_open(void *spec, struct io_dev_info **dev_info);
+static int fip_file_open(struct io_dev_info *dev_info, const void *spec,
+			  struct io_entity *entity);
+static int fip_file_len(struct io_entity *entity, size_t *length);
+static int fip_file_read(struct io_entity *entity, void *buffer, size_t length,
+			  size_t *length_read);
+static int fip_file_close(struct io_entity *entity);
+static int fip_dev_init(struct io_dev_info *dev_info, const void *init_params);
+static int fip_dev_close(struct io_dev_info *dev_info);
+
+
+static inline int copy_uuid(uuid_t *dst, const uuid_t *src)
+{
+	memcpy(dst, src, sizeof(uuid_t));
+	return 0;
+}
+
+
+/* Return 0 for equal uuids. */
+static inline int compare_uuids(const uuid_t *uuid1, const uuid_t *uuid2)
+{
+	return memcmp(uuid1, uuid2, sizeof(uuid_t));
+}
+
+
+/* TODO: We could check version numbers or do a package checksum? */
+static inline int is_valid_header(fip_toc_header *header)
+{
+	if ((header->name == TOC_HEADER_NAME) && (header->serial_number != 0)) {
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+
+static int file_to_uuid(const char *filename, uuid_t *uuid)
+{
+	int i;
+	int status = -EINVAL;
+
+	for (i = 0; i < (sizeof(name_uuid)/sizeof(plat_fip_name_uuid)); i++) {
+		if (strcmp(filename, name_uuid[i].name) == 0) {
+			copy_uuid(uuid, &name_uuid[i].uuid);
+			status = 0;
+			break;
+		}
+	}
+	return status;
+}
+
+
+/* Identify the device type as a virtual driver */
+io_type device_type_fip(void)
+{
+	return IO_TYPE_FIRMWARE_IMAGE_PACKAGE;
+}
+
+
+static struct io_dev_connector fip_dev_connector = {
+	.dev_open = fip_dev_open
+};
+
+
+static struct io_dev_funcs fip_dev_funcs = {
+	.type = device_type_fip,
+	.open = fip_file_open,
+	.seek = NULL,
+	.size = fip_file_len,
+	.read = fip_file_read,
+	.write = NULL,
+	.close = fip_file_close,
+	.dev_init = fip_dev_init,
+	.dev_close = fip_dev_close,
+};
+
+
+static struct io_dev_info fip_dev_info = {
+	.funcs = &fip_dev_funcs,
+	.info = (uintptr_t)NULL
+};
+
+
+/* Open a connection to the FIP device */
+static int fip_dev_open(void *spec __attribute__((unused)),
+			 struct io_dev_info **dev_info)
+{
+	assert(dev_info != NULL);
+	*dev_info = &fip_dev_info;
+
+	return IO_SUCCESS;
+}
+
+
+/* Do some basic package checks. */
+static int fip_dev_init(struct io_dev_info *dev_info, const void *init_params)
+{
+	int result = IO_FAIL;
+	char *image_name = (char *)init_params;
+	io_handle backend_handle;
+	fip_toc_header header;
+	size_t bytes_read;
+
+	/* Obtain a reference to the image by querying the platform layer */
+	result = plat_get_image_source(image_name, &backend_dev_handle,
+				       &backend_image_spec);
+	if (result != IO_SUCCESS) {
+		ERROR("Failed to obtain reference to image '%s' (%i)\n",
+			image_name, result);
+		result = IO_FAIL;
+		goto fip_dev_init_exit;
+	}
+
+	/* Attempt to access the FIP image */
+	result = io_open(backend_dev_handle, backend_image_spec,
+			 &backend_handle);
+	if (result != IO_SUCCESS) {
+		ERROR("Failed to access image '%s' (%i)\n", image_name, result);
+		result = IO_FAIL;
+		goto fip_dev_init_exit;
+	}
+
+	result = io_read(backend_handle, &header, sizeof(header), &bytes_read);
+	if (result == IO_SUCCESS) {
+		if (!is_valid_header(&header)) {
+			ERROR("Firmware Image Package header check failed.\n");
+			result = IO_FAIL;
+		} else {
+			INFO("FIP header looks OK.\n");
+		}
+	}
+
+	io_close(backend_handle);
+
+ fip_dev_init_exit:
+	return result;
+}
+
+/* Close a connection to the FIP device */
+static int fip_dev_close(struct io_dev_info *dev_info)
+{
+	/* TODO: Consider tracking open files and cleaning them up here */
+
+	/* Clear the backend. */
+	backend_dev_handle = NULL;
+	backend_image_spec = NULL;
+
+	return IO_SUCCESS;
+}
+
+
+/* Open a file for access from package. */
+static int fip_file_open(struct io_dev_info *dev_info, const void *spec,
+			 struct io_entity *entity)
+{
+	int result = IO_FAIL;
+	io_handle backend_handle;
+	uuid_t file_uuid;
+	const io_file_spec *file_spec = (io_file_spec *)spec;
+	size_t bytes_read;
+	int found_file = 0;
+
+	assert(file_spec != NULL);
+	assert(entity != NULL);
+
+	/* Can only have one file open at a time for the moment. We need to
+	 * track state like file cursor position. We know the header lives at
+	 * offset zero, so this entry should never be zero for an active file.
+	 * When the system supports dynamic memory allocation we can allow more
+	 * than one open file at a time if needed.
+	 */
+	if (current_file.entry.offset_address != 0) {
+		ERROR("fip_file_open : Only one open file at a time.\n");
+		return IO_RESOURCES_EXHAUSTED;
+	}
+
+	/* Attempt to access the FIP image */
+	result = io_open(backend_dev_handle, backend_image_spec,
+			 &backend_handle);
+	if (result != IO_SUCCESS) {
+		ERROR("Failed to open Firmware Image Package (%i)\n", result);
+		result = IO_FAIL;
+		goto fip_file_open_exit;
+	}
+
+	/* Seek past the FIP header into the Table of Contents */
+	result = io_seek(backend_handle, IO_SEEK_SET, sizeof(fip_toc_header));
+	if (result != IO_SUCCESS) {
+		ERROR("fip_file_open: failed to seek\n");
+		result = IO_FAIL;
+		goto fip_file_open_close;
+	}
+
+	file_to_uuid(file_spec->path, &file_uuid);
+
+	found_file = 0;
+	do {
+		result = io_read(backend_handle, &current_file.entry,
+				 sizeof(current_file.entry),
+				 &bytes_read);
+		if (result == IO_SUCCESS) {
+			if (compare_uuids(&current_file.entry.uuid,
+					  &file_uuid) == 0) {
+				found_file = 1;
+				break;
+			}
+		} else {
+			ERROR("Failed to read FIP (%i)\n", result);
+			goto fip_file_open_close;
+		}
+	} while (compare_uuids(&current_file.entry.uuid, &uuid_null) != 0);
+
+	if (found_file == 1) {
+		/* All fine. Update entity info with file state and return. Set
+		 * the file position to 0. The 'current_file.entry' holds the
+		 * base and size of the file.
+		 */
+		current_file.file_pos = 0;
+		entity->info = (uintptr_t)&current_file;
+	} else {
+		/* Did not find the file in the FIP. */
+		result = IO_FAIL;
+	}
+
+ fip_file_open_close:
+	io_close(backend_handle);
+
+ fip_file_open_exit:
+	return result;
+}
+
+
+/* Return the size of a file in package */
+static int fip_file_len(struct io_entity *entity, size_t *length)
+{
+	assert(entity != NULL);
+	assert(length != NULL);
+
+	*length =  ((file_state *)entity->info)->entry.size;
+
+	return IO_SUCCESS;
+}
+
+
+/* Read data from a file in package */
+static int fip_file_read(struct io_entity *entity, void *buffer, size_t length,
+			  size_t *length_read)
+{
+	int result = IO_FAIL;
+	file_state *fp;
+	size_t file_offset;
+	size_t bytes_read;
+	io_handle backend_handle;
+
+	assert(entity != NULL);
+	assert(buffer != NULL);
+	assert(length_read != NULL);
+	assert((void *)entity->info != NULL);
+
+	/* Open the backend, attempt to access the blob image */
+	result = io_open(backend_dev_handle, backend_image_spec,
+			 &backend_handle);
+	if (result != IO_SUCCESS) {
+		ERROR("Failed to open FIP (%i)\n", result);
+		result = IO_FAIL;
+		goto fip_file_read_exit;
+	}
+
+	fp = (file_state *)entity->info;
+
+	/* Seek to the position in the FIP where the payload lives */
+	file_offset = fp->entry.offset_address + fp->file_pos;
+	result = io_seek(backend_handle, IO_SEEK_SET, file_offset);
+	if (result != IO_SUCCESS) {
+		ERROR("fip_file_read: failed to seek\n");
+		result = IO_FAIL;
+		goto fip_file_read_close;
+	}
+
+	result = io_read(backend_handle, buffer, length, &bytes_read);
+	if (result != IO_SUCCESS) {
+		/* We cannot read our data. Fail. */
+		ERROR("Failed to read payload (%i)\n", result);
+		result = IO_FAIL;
+		goto fip_file_read_close;
+	} else {
+		/* Set caller length and new file position. */
+		*length_read = bytes_read;
+		fp->file_pos += bytes_read;
+	}
+
+/* Close the backend. */
+ fip_file_read_close:
+	io_close(backend_handle);
+
+ fip_file_read_exit:
+	return result;
+}
+
+
+/* Close a file in package */
+static int fip_file_close(struct io_entity *entity)
+{
+	/* Clear our current file pointer.
+	 * If we had malloc() we would free() here.
+	 */
+	if (current_file.entry.offset_address != 0) {
+		memset(&current_file, 0, sizeof(current_file));
+	}
+
+	/* Clear the Entity info. */
+	entity->info = 0;
+
+	return IO_SUCCESS;
+}
+
+/* Exported functions */
+
+/* Register the Firmware Image Package driver with the IO abstraction */
+int register_io_dev_fip(struct io_dev_connector **dev_con)
+{
+	int result = IO_FAIL;
+	assert(dev_con != NULL);
+
+	result = io_register_device(&fip_dev_info);
+	if (result == IO_SUCCESS)
+		*dev_con = &fip_dev_connector;
+
+	return result;
+}
diff --git a/drivers/io/io_fip.h b/drivers/io/io_fip.h
new file mode 100644
index 0000000..56dd1e0
--- /dev/null
+++ b/drivers/io/io_fip.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014 ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __IO_FIP_H__
+#define __IO_FIP_H__
+
+int register_io_dev_fip(struct io_dev_connector **dev_con);
+
+#endif /* __IO_FIP_H__ */
diff --git a/drivers/io/io_memmap.c b/drivers/io/io_memmap.c
new file mode 100644
index 0000000..0809973
--- /dev/null
+++ b/drivers/io/io_memmap.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <string.h>
+#include "io_storage.h"
+#include "io_driver.h"
+#include "debug.h"
+
+/* As we need to be able to keep state for seek, only one file can be open
+ * at a time. Make this a structure and point to the entity->info. When we
+ * can malloc memory we can change this to support more open files.
+ */
+typedef struct {
+	/* Use the 'in_use' flag as any value for base and file_pos could be
+	 * valid.
+	 */
+	int	in_use;
+	size_t	base;
+	size_t  file_pos;
+} file_state;
+
+static file_state current_file = {0};
+
+/* Identify the device type as memmap */
+io_type device_type_memmap(void)
+{
+	return IO_TYPE_MEMMAP;
+}
+
+/* Memmap device functions */
+static int memmap_dev_open(void *spec, struct io_dev_info **dev_info);
+static int memmap_block_open(struct io_dev_info *dev_info, const void *spec,
+			     struct io_entity *entity);
+static int memmap_block_seek(struct io_entity *entity, int mode,
+			     ssize_t offset);
+static int memmap_block_read(struct io_entity *entity, void *buffer,
+			     size_t length, size_t *length_read);
+static int memmap_block_write(struct io_entity *entity, const void *buffer,
+			      size_t length, size_t *length_written);
+static int memmap_block_close(struct io_entity *entity);
+static int memmap_dev_close(struct io_dev_info *dev_info);
+
+
+static struct io_dev_connector memmap_dev_connector = {
+	.dev_open = memmap_dev_open
+};
+
+
+static struct io_dev_funcs memmap_dev_funcs = {
+	.type = device_type_memmap,
+	.open = memmap_block_open,
+	.seek = memmap_block_seek,
+	.size = NULL,
+	.read = memmap_block_read,
+	.write = memmap_block_write,
+	.close = memmap_block_close,
+	.dev_init = NULL,
+	.dev_close = memmap_dev_close,
+};
+
+
+static struct io_dev_info memmap_dev_info = {
+	.funcs = &memmap_dev_funcs,
+	.info = (uintptr_t)NULL
+};
+
+
+/* Open a connection to the memmap device */
+static int memmap_dev_open(void *spec __attribute__((unused)),
+			   struct io_dev_info **dev_info)
+{
+	assert(dev_info != NULL);
+	*dev_info = &memmap_dev_info;
+
+	return IO_SUCCESS;
+}
+
+
+
+/* Close a connection to the memmap device */
+static int memmap_dev_close(struct io_dev_info *dev_info)
+{
+	/* NOP */
+	/* TODO: Consider tracking open files and cleaning them up here */
+	return IO_SUCCESS;
+}
+
+
+/* Open a file on the memmap device */
+/* TODO: Can we do any sensible limit checks on requested memory */
+static int memmap_block_open(struct io_dev_info *dev_info, const void *spec,
+			     struct io_entity *entity)
+{
+	int result = IO_FAIL;
+	const io_block_spec *block_spec = (io_block_spec *)spec;
+
+	/* Since we need to track open state for seek() we only allow one open
+	 * spec at a time. When we have dynamic memory we can malloc and set
+	 * entity->info.
+	 */
+	if (current_file.in_use == 0) {
+		assert(block_spec != NULL);
+		assert(entity != NULL);
+
+		current_file.in_use = 1;
+		current_file.base = block_spec->offset;
+		/* File cursor offset for seek and incremental reads etc. */
+		current_file.file_pos = 0;
+		entity->info = (uintptr_t)&current_file;
+		result = IO_SUCCESS;
+	} else {
+		ERROR("A Memmap device is already active. Close first.\n");
+		result = IO_RESOURCES_EXHAUSTED;
+	}
+
+	return result;
+}
+
+
+/* Seek to a particular file offset on the memmap device */
+static int memmap_block_seek(struct io_entity *entity, int mode, ssize_t offset)
+{
+	int result = IO_FAIL;
+
+	/* We only support IO_SEEK_SET for the moment. */
+	if (mode == IO_SEEK_SET) {
+		assert(entity != NULL);
+
+		/* TODO: can we do some basic limit checks on seek? */
+		((file_state *)entity->info)->file_pos = offset;
+		result = IO_SUCCESS;
+	} else {
+		result = IO_FAIL;
+	}
+
+	return result;
+}
+
+
+/* Read data from a file on the memmap device */
+static int memmap_block_read(struct io_entity *entity, void *buffer,
+			     size_t length, size_t *length_read)
+{
+	file_state *fp;
+
+	assert(entity != NULL);
+	assert(buffer != NULL);
+	assert(length_read != NULL);
+
+	fp = (file_state *)entity->info;
+
+	memcpy(buffer, (void *)(fp->base + fp->file_pos), length);
+
+	*length_read = length;
+	/* advance the file 'cursor' for incremental reads */
+	fp->file_pos += length;
+
+	return IO_SUCCESS;
+}
+
+
+/* Write data to a file on the memmap device */
+static int memmap_block_write(struct io_entity *entity, const void *buffer,
+			      size_t length, size_t *length_written)
+{
+	file_state *fp;
+
+	assert(entity != NULL);
+	assert(buffer != NULL);
+	assert(length_written != NULL);
+
+	fp = (file_state *)entity->info;
+
+	memcpy((void *)(fp->base + fp->file_pos), buffer, length);
+
+	*length_written = length;
+
+	/* advance the file 'cursor' for incremental writes */
+	fp->file_pos += length;
+
+	return IO_SUCCESS;
+}
+
+
+/* Close a file on the memmap device */
+static int memmap_block_close(struct io_entity *entity)
+{
+	assert(entity != NULL);
+
+	entity->info = 0;
+
+	/* This would be a mem free() if we had malloc.*/
+	memset((void *)&current_file, 0, sizeof(current_file));
+
+	return IO_SUCCESS;
+}
+
+
+/* Exported functions */
+
+/* Register the memmap driver with the IO abstraction */
+int register_io_dev_memmap(struct io_dev_connector **dev_con)
+{
+	int result = IO_FAIL;
+	assert(dev_con != NULL);
+
+	result = io_register_device(&memmap_dev_info);
+	if (result == IO_SUCCESS)
+		*dev_con = &memmap_dev_connector;
+
+	return result;
+}
diff --git a/drivers/io/io_memmap.h b/drivers/io/io_memmap.h
new file mode 100644
index 0000000..5fa7bc9
--- /dev/null
+++ b/drivers/io/io_memmap.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __IO_MEMMAP_H__
+#define __IO_MEMMAP_H__
+
+int register_io_dev_memmap(struct io_dev_connector **dev_con);
+
+#endif /* __IO_MEMMAP_H__ */