Implement VFS syscalls

libmsl/m/system.h

@@ -1,6 +1,7 @@
 #ifndef _LIBMSL_M_SYSTEM_H
 #define _LIBMSL_M_SYSTEM_H
 
+#include <m/fs_desc_buffer.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -52,4 +53,16 @@ int device_do (int device_id, int cmd, void* a1, void* a2, void* a3, void* a4);
 /* Run external ELF program */
 int exec (const char* path);
 
+/* Open a file */
+int open (const char* path);
+
+/* Close a file */
+int close (const char* path);
+
+/* Read a file */
+int read (const char* path, size_t off, uint8_t* buffer, size_t size);
+
+/* describe a file */
+int describe (const char* path, struct fs_desc_buffer* desc);
+
 #endif // _LIBMSL_M_SYSTEM_H