ARMv8 Trusted Firmware release v0.2
diff --git a/lib/semihosting/semihosting.c b/lib/semihosting/semihosting.c
new file mode 100644
index 0000000..558973a
--- /dev/null
+++ b/lib/semihosting/semihosting.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2013, ARM Limited. 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 <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <semihosting.h>
+
+#ifndef SEMIHOSTING_SUPPORTED
+#define SEMIHOSTING_SUPPORTED  1
+#endif
+
+extern int semihosting_call(unsigned int operation,
+			    void *system_block_address);
+
+typedef struct {
+	const char *file_name;
+	unsigned int mode;
+	unsigned int name_length;
+} smh_file_open_block;
+
+typedef struct {
+	int handle;
+	void *buffer;
+	unsigned int length;
+} smh_file_read_write_block;
+
+typedef struct {
+	int handle;
+	unsigned int location;
+} smh_file_seek_block;
+
+typedef struct {
+	char *command_line;
+	unsigned int command_length;
+} smh_system_block;
+
+int semihosting_connection_supported(void)
+{
+	return SEMIHOSTING_SUPPORTED;
+}
+
+int semihosting_file_open(const char *file_name, unsigned int mode)
+{
+	smh_file_open_block open_block;
+
+	open_block.file_name = file_name;
+	open_block.mode = mode;
+	open_block.name_length = strlen(file_name);
+
+	return semihosting_call(SEMIHOSTING_SYS_OPEN,
+				(void *) &open_block);
+}
+
+int semihosting_file_seek(int file_handle, unsigned int offset)
+{
+	smh_file_seek_block seek_block;
+	int result;
+
+	seek_block.handle = file_handle;
+	seek_block.location = offset;
+
+	result = semihosting_call(SEMIHOSTING_SYS_SEEK,
+				  (void *) &seek_block);
+
+	if (result)
+		result = semihosting_call(SEMIHOSTING_SYS_ERRNO, 0);
+
+	return result;
+}
+
+int semihosting_file_read(int file_handle, int *length, void *buffer)
+{
+	smh_file_read_write_block read_block;
+	int result = -EINVAL;
+
+	if ((length == NULL) || (buffer == NULL))
+		return result;
+
+	read_block.handle = file_handle;
+	read_block.buffer = buffer;
+	read_block.length = *length;
+
+	result = semihosting_call(SEMIHOSTING_SYS_READ,
+				  (void *) &read_block);
+
+	if (result == *length) {
+		return -EINVAL;
+	} else if (result < *length) {
+		*length -= result;
+		return 0;
+	} else
+		return result;
+}
+
+int semihosting_file_write(int file_handle, int *length, void *buffer)
+{
+	smh_file_read_write_block write_block;
+
+	if ((length == NULL) || (buffer == NULL))
+		return -EINVAL;
+
+	write_block.handle = file_handle;
+	write_block.buffer = buffer;
+	write_block.length = *length;
+
+	*length = semihosting_call(SEMIHOSTING_SYS_WRITE,
+				   (void *) &write_block);
+
+	return *length;
+}
+
+int semihosting_file_close(int file_handle)
+{
+	return semihosting_call(SEMIHOSTING_SYS_CLOSE,
+				(void *) &file_handle);
+}
+
+int semihosting_file_length(int file_handle)
+{
+	return semihosting_call(SEMIHOSTING_SYS_FLEN,
+				(void *) &file_handle);
+}
+
+char semihosting_read_char(void)
+{
+	return semihosting_call(SEMIHOSTING_SYS_READC, NULL);
+}
+
+void semihosting_write_char(char character)
+{
+	semihosting_call(SEMIHOSTING_SYS_WRITEC, (void *) &character);
+}
+
+void semihosting_write_string(char *string)
+{
+	semihosting_call(SEMIHOSTING_SYS_WRITE0, (void *) string);
+}
+
+int semihosting_system(char *command_line)
+{
+	smh_system_block system_block;
+
+	system_block.command_line = command_line;
+	system_block.command_length = strlen(command_line);
+
+	return semihosting_call(SEMIHOSTING_SYS_SYSTEM,
+				(void *) &system_block);
+}
+
+int semihosting_get_flen(const char *file_name)
+{
+	int file_handle, length;
+
+	assert(semihosting_connection_supported());
+
+	file_handle = semihosting_file_open(file_name, FOPEN_MODE_RB);
+	if (file_handle == -1)
+		return file_handle;
+
+	/* Find the length of the file */
+	length = semihosting_file_length(file_handle);
+
+	return semihosting_file_close(file_handle) ? -1 : length;
+}
+
+int semihosting_download_file(const char *file_name,
+			      int buf_size,
+			      void *buf)
+{
+	int ret = -EINVAL, file_handle, length;
+
+	/* Null pointer check */
+	if (!buf)
+		return ret;
+
+	assert(semihosting_connection_supported());
+
+	file_handle = semihosting_file_open(file_name, FOPEN_MODE_RB);
+	if (file_handle == -1)
+		return ret;
+
+	/* Find the actual length of the file */
+	length = semihosting_file_length(file_handle);
+	if (length == -1)
+		goto semihosting_fail;
+
+	/* Signal error if we do not have enough space for the file */
+	if (length > buf_size)
+		goto semihosting_fail;
+
+	/*
+	 * A successful read will return 0 in which case we pass back
+	 * the actual number of bytes read. Else we pass a negative
+	 * value indicating an error.
+	 */
+	ret = semihosting_file_read(file_handle, &length, buf);
+	if (ret)
+		goto semihosting_fail;
+	else
+		ret = length;
+
+semihosting_fail:
+	semihosting_file_close(file_handle);
+	return ret;
+}