diff --git a/lib/semihosting/semihosting.c b/lib/semihosting/semihosting.c
index 1a7ac60..d5b8524 100644
--- a/lib/semihosting/semihosting.c
+++ b/lib/semihosting/semihosting.c
@@ -31,43 +31,44 @@
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
+#include <stdio.h>
 #include <semihosting.h>
 
 #ifndef SEMIHOSTING_SUPPORTED
 #define SEMIHOSTING_SUPPORTED  1
 #endif
 
-extern int semihosting_call(unsigned int operation,
+extern long semihosting_call(unsigned long operation,
 			    void *system_block_address);
 
 typedef struct {
 	const char *file_name;
-	unsigned int mode;
-	unsigned int name_length;
+	unsigned long mode;
+	size_t name_length;
 } smh_file_open_block;
 
 typedef struct {
-	int handle;
+	long handle;
 	void *buffer;
-	unsigned int length;
+	size_t length;
 } smh_file_read_write_block;
 
 typedef struct {
-	int handle;
-	unsigned int location;
+	long handle;
+	ssize_t location;
 } smh_file_seek_block;
 
 typedef struct {
 	char *command_line;
-	unsigned int command_length;
+	size_t command_length;
 } smh_system_block;
 
-int semihosting_connection_supported(void)
+long semihosting_connection_supported(void)
 {
 	return SEMIHOSTING_SUPPORTED;
 }
 
-int semihosting_file_open(const char *file_name, unsigned int mode)
+long semihosting_file_open(const char *file_name, size_t mode)
 {
 	smh_file_open_block open_block;
 
@@ -79,10 +80,10 @@
 				(void *) &open_block);
 }
 
-int semihosting_file_seek(int file_handle, unsigned int offset)
+long semihosting_file_seek(long file_handle, ssize_t offset)
 {
 	smh_file_seek_block seek_block;
-	int result;
+	long result;
 
 	seek_block.handle = file_handle;
 	seek_block.location = offset;
@@ -96,10 +97,10 @@
 	return result;
 }
 
-int semihosting_file_read(int file_handle, int *length, void *buffer)
+long semihosting_file_read(long file_handle, size_t *length, void *buffer)
 {
 	smh_file_read_write_block read_block;
-	int result = -EINVAL;
+	long result = -EINVAL;
 
 	if ((length == NULL) || (buffer == NULL))
 		return result;
@@ -120,7 +121,9 @@
 		return result;
 }
 
-int semihosting_file_write(int file_handle, int *length, const void *buffer)
+long semihosting_file_write(long file_handle,
+			    size_t *length,
+			    const void *buffer)
 {
 	smh_file_read_write_block write_block;
 
@@ -137,13 +140,13 @@
 	return *length;
 }
 
-int semihosting_file_close(int file_handle)
+long semihosting_file_close(long file_handle)
 {
 	return semihosting_call(SEMIHOSTING_SYS_CLOSE,
 				(void *) &file_handle);
 }
 
-int semihosting_file_length(int file_handle)
+long semihosting_file_length(long file_handle)
 {
 	return semihosting_call(SEMIHOSTING_SYS_FLEN,
 				(void *) &file_handle);
@@ -164,7 +167,7 @@
 	semihosting_call(SEMIHOSTING_SYS_WRITE0, (void *) string);
 }
 
-int semihosting_system(char *command_line)
+long semihosting_system(char *command_line)
 {
 	smh_system_block system_block;
 
@@ -175,9 +178,10 @@
 				(void *) &system_block);
 }
 
-int semihosting_get_flen(const char *file_name)
+long semihosting_get_flen(const char *file_name)
 {
-	int file_handle, length;
+	long file_handle;
+	size_t length;
 
 	assert(semihosting_connection_supported());
 
@@ -191,11 +195,13 @@
 	return semihosting_file_close(file_handle) ? -1 : length;
 }
 
-int semihosting_download_file(const char *file_name,
-			      int buf_size,
+long semihosting_download_file(const char *file_name,
+			      size_t buf_size,
 			      void *buf)
 {
-	int ret = -EINVAL, file_handle, length;
+	long ret = -EINVAL;
+	size_t length;
+	long file_handle;
 
 	/* Null pointer check */
 	if (!buf)