diff --git a/drivers/io/io_semihosting.c b/drivers/io/io_semihosting.c
index 3c92c6d..8e62be1 100644
--- a/drivers/io/io_semihosting.c
+++ b/drivers/io/io_semihosting.c
@@ -183,7 +183,6 @@
 static int sh_file_write(io_entity_t *entity, const uintptr_t buffer,
 		size_t length, size_t *length_written)
 {
-	int result = IO_FAIL;
 	long sh_result = -1;
 	long file_handle;
 	size_t bytes = length;
@@ -196,13 +195,9 @@
 
 	sh_result = semihosting_file_write(file_handle, &bytes, buffer);
 
-	if (sh_result >= 0) {
-		*length_written = sh_result;
-		result = IO_SUCCESS;
-	} else
-		result = IO_FAIL;
+	*length_written = length - bytes;
 
-	return result;
+	return (sh_result == 0) ? IO_SUCCESS : IO_FAIL;
 }
 
 
diff --git a/lib/semihosting/semihosting.c b/lib/semihosting/semihosting.c
index 849ec12..b4f53d2 100644
--- a/lib/semihosting/semihosting.c
+++ b/lib/semihosting/semihosting.c
@@ -125,6 +125,7 @@
 			    const uintptr_t buffer)
 {
 	smh_file_read_write_block_t write_block;
+	long result = -EINVAL;
 
 	if ((length == NULL) || (buffer == (uintptr_t)NULL))
 		return -EINVAL;
@@ -133,10 +134,12 @@
 	write_block.buffer = (uintptr_t)buffer; /* cast away const */
 	write_block.length = *length;
 
-	*length = semihosting_call(SEMIHOSTING_SYS_WRITE,
+	result = semihosting_call(SEMIHOSTING_SYS_WRITE,
 				   (void *) &write_block);
 
-	return *length;
+	*length = result;
+
+	return (result == 0) ? 0 : -EINVAL;
 }
 
 long semihosting_file_close(long file_handle)