added syscall interface to debug variables

riscemu/Syscall.py

@@ -169,4 +169,10 @@ class SyscallInterface:
     def get_syscall_symbols(self):
         return {
             ('SCALL_' + name.upper()): num for num, name in SYSCALLS.items()
-        }
+        }
+
+    def __repr__(self):
+        return "{}(\n\tfiles={}\n)".format(
+            self.__class__.__name__,
+            self.open_files
+        )

riscemu/debug.py

@@ -14,6 +14,7 @@ def launch_debug_session(cpu: 'CPU', mmu: 'MMU', reg: 'Registers', prompt=""):
     registers = reg
     memory = mmu
     mem = mmu
+    syscall_interface = cpu.syscall_int
 
     vars = globals()
     vars.update(locals())