Added exception hierarchy except for OSError and UnicodeError (requires arguments). Comment out the errors that aren't needed if memory becomes an issue.
diff --git a/py/obj.h b/py/obj.h
index 8d40c3f..3217c4a 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -184,9 +184,53 @@
 typedef struct _mp_obj_type_t mp_obj_type_t;
 
 // Constant types, globally accessible
-
 extern const mp_obj_type_t mp_type_type;
+
+// Exceptions
 extern const mp_obj_type_t mp_type_BaseException;
+extern const mp_obj_type_t mp_type_ArithmeticError;
+extern const mp_obj_type_t mp_type_AssertionError;
+extern const mp_obj_type_t mp_type_AttributeError;
+extern const mp_obj_type_t mp_type_BufferError;
+extern const mp_obj_type_t mp_type_BytesWarning;
+extern const mp_obj_type_t mp_type_DeprecationWarning;
+extern const mp_obj_type_t mp_type_EOFError;
+extern const mp_obj_type_t mp_type_EnvironmentError;
+extern const mp_obj_type_t mp_type_Exception;
+extern const mp_obj_type_t mp_type_FloatingPointError;
+extern const mp_obj_type_t mp_type_FutureWarning;
+extern const mp_obj_type_t mp_type_GeneratorExit;
+extern const mp_obj_type_t mp_type_IOError;
+extern const mp_obj_type_t mp_type_ImportError;
+extern const mp_obj_type_t mp_type_ImportWarning;
+extern const mp_obj_type_t mp_type_IndentationError;
+extern const mp_obj_type_t mp_type_IndexError;
+extern const mp_obj_type_t mp_type_KeyError;
+extern const mp_obj_type_t mp_type_LookupError;
+extern const mp_obj_type_t mp_type_MemoryError;
+extern const mp_obj_type_t mp_type_NameError;
+extern const mp_obj_type_t mp_type_NotImplementedError;
+extern const mp_obj_type_t mp_type_OSError;
+extern const mp_obj_type_t mp_type_OverflowError;
+extern const mp_obj_type_t mp_type_PendingDeprecationWarning;
+extern const mp_obj_type_t mp_type_ReferenceError;
+extern const mp_obj_type_t mp_type_ResourceWarning;
+extern const mp_obj_type_t mp_type_RuntimeError;
+extern const mp_obj_type_t mp_type_RuntimeWarning;
+extern const mp_obj_type_t mp_type_SyntaxError;
+extern const mp_obj_type_t mp_type_SyntaxWarning;
+extern const mp_obj_type_t mp_type_SystemError;
+extern const mp_obj_type_t mp_type_SystemExit;
+extern const mp_obj_type_t mp_type_TabError;
+extern const mp_obj_type_t mp_type_TypeError;
+extern const mp_obj_type_t mp_type_UnboundLocalError;
+extern const mp_obj_type_t mp_type_UserWarning;
+extern const mp_obj_type_t mp_type_ValueError;
+extern const mp_obj_type_t mp_type_Warning;
+extern const mp_obj_type_t mp_type_ZeroDivisionError;
+
+extern const mp_obj_type_t mp_type_StopIteration;
+/*extern const mp_obj_type_t mp_type_BaseException;
 extern const mp_obj_type_t mp_type_AssertionError;
 extern const mp_obj_type_t mp_type_AttributeError;
 extern const mp_obj_type_t mp_type_ImportError;
@@ -201,7 +245,7 @@
 extern const mp_obj_type_t mp_type_OSError;
 extern const mp_obj_type_t mp_type_NotImplementedError;
 extern const mp_obj_type_t mp_type_StopIteration;
-extern const mp_obj_type_t mp_type_ZeroDivisionError;
+extern const mp_obj_type_t mp_type_ZeroDivisionError;*/
 
 // Constant objects, globally accessible
 
diff --git a/py/objexcept.c b/py/objexcept.c
index 3f636ff..7fd783b 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -77,23 +77,78 @@
     .bases_tuple = (mp_obj_t)&mp_type_ ## base_name ## _base_tuple, \
 };
 
+// List of all exceptions, arranged as in the table at:
+// http://docs.python.org/3.3/library/exceptions.html
 MP_DEFINE_EXCEPTION_BASE(BaseException)
-
-MP_DEFINE_EXCEPTION(AssertionError, BaseException)
-MP_DEFINE_EXCEPTION(AttributeError, BaseException)
-MP_DEFINE_EXCEPTION(ImportError, BaseException)
-MP_DEFINE_EXCEPTION(IndentationError, BaseException)
-MP_DEFINE_EXCEPTION(IndexError, BaseException)
-MP_DEFINE_EXCEPTION(KeyError, BaseException)
-MP_DEFINE_EXCEPTION(NameError, BaseException)
-MP_DEFINE_EXCEPTION(SyntaxError, BaseException)
-MP_DEFINE_EXCEPTION(TypeError, BaseException)
-MP_DEFINE_EXCEPTION(ValueError, BaseException)
-MP_DEFINE_EXCEPTION(OverflowError, BaseException)
-MP_DEFINE_EXCEPTION(OSError, BaseException)
-MP_DEFINE_EXCEPTION(NotImplementedError, BaseException)
-MP_DEFINE_EXCEPTION(StopIteration, BaseException)
-MP_DEFINE_EXCEPTION(ZeroDivisionError, BaseException)
+MP_DEFINE_EXCEPTION(SystemExit, BaseException)
+//MP_DEFINE_EXCEPTION(KeyboardInterrupt, BaseException)
+MP_DEFINE_EXCEPTION(GeneratorExit, BaseException)
+MP_DEFINE_EXCEPTION(Exception, BaseException)
+  MP_DEFINE_EXCEPTION_BASE(Exception)
+  MP_DEFINE_EXCEPTION(StopIteration, Exception)
+  MP_DEFINE_EXCEPTION(ArithmeticError, Exception)
+    MP_DEFINE_EXCEPTION_BASE(ArithmeticError)
+    MP_DEFINE_EXCEPTION(FloatingPointError, ArithmeticError)
+    MP_DEFINE_EXCEPTION(OverflowError, ArithmeticError)
+    MP_DEFINE_EXCEPTION(ZeroDivisionError, ArithmeticError)
+  MP_DEFINE_EXCEPTION(AssertionError, Exception)
+  MP_DEFINE_EXCEPTION(AttributeError, Exception)
+  MP_DEFINE_EXCEPTION(BufferError, Exception)
+  MP_DEFINE_EXCEPTION(EnvironmentError, Exception)
+  MP_DEFINE_EXCEPTION(EOFError, Exception)
+  MP_DEFINE_EXCEPTION(ImportError, Exception)
+  MP_DEFINE_EXCEPTION(IOError, Exception)
+  MP_DEFINE_EXCEPTION(LookupError, Exception)
+    MP_DEFINE_EXCEPTION_BASE(LookupError)
+    MP_DEFINE_EXCEPTION(IndexError, LookupError)
+    MP_DEFINE_EXCEPTION(KeyError, LookupError)
+  MP_DEFINE_EXCEPTION(MemoryError, Exception)
+  MP_DEFINE_EXCEPTION(NameError, Exception)
+    MP_DEFINE_EXCEPTION_BASE(NameError)
+    MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
+  MP_DEFINE_EXCEPTION(OSError, Exception)
+    // Probably don't need these
+    /*MP_DEFINE_EXCEPTION_BASE(OSError)
+    MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
+    MP_DEFINE_EXCEPTION(ChildProcessError, OSError)
+    MP_DEFINE_EXCEPTION(ConnectionError, OSError)
+      MP_DEFINE_EXCEPTION(BrokenPipeError, ConnectionError)
+      MP_DEFINE_EXCEPTION(ConnectionAbortedError, ConnectionError)
+      MP_DEFINE_EXCEPTION(ConnectionRefusedError, ConnectionError)
+      MP_DEFINE_EXCEPTION(ConnectionResetError, ConnectionError)
+    MP_DEFINE_EXCEPTION(FileExistsError, OSError)
+    MP_DEFINE_EXCEPTION(FileNotFoundError, OSError)
+    MP_DEFINE_EXCEPTION(InterruptedError, OSError)
+    MP_DEFINE_EXCEPTION(IsADirectoryError, OSError)
+    MP_DEFINE_EXCEPTION(NotADirectoryError, OSError)
+    MP_DEFINE_EXCEPTION(PermissionError, OSError)
+    MP_DEFINE_EXCEPTION(ProcessLookupError, OSError)
+    MP_DEFINE_EXCEPTION(TimeoutError, OSError)*/
+  MP_DEFINE_EXCEPTION(ReferenceError, Exception)
+  MP_DEFINE_EXCEPTION(RuntimeError, Exception)
+    MP_DEFINE_EXCEPTION_BASE(RuntimeError)
+    MP_DEFINE_EXCEPTION(NotImplementedError, RuntimeError)
+  MP_DEFINE_EXCEPTION(SyntaxError, Exception)
+    MP_DEFINE_EXCEPTION_BASE(SyntaxError)
+    MP_DEFINE_EXCEPTION(IndentationError, SyntaxError)
+      MP_DEFINE_EXCEPTION_BASE(IndentationError)
+      MP_DEFINE_EXCEPTION(TabError, IndentationError)
+  MP_DEFINE_EXCEPTION(SystemError, Exception)
+  MP_DEFINE_EXCEPTION(TypeError, Exception)
+  MP_DEFINE_EXCEPTION(ValueError, Exception)
+    //TODO: Implement UnicodeErrors which take arguments
+  MP_DEFINE_EXCEPTION(Warning, Exception)
+    MP_DEFINE_EXCEPTION_BASE(Warning)
+    MP_DEFINE_EXCEPTION(DeprecationWarning, Warning)
+    MP_DEFINE_EXCEPTION(PendingDeprecationWarning, Warning)
+    MP_DEFINE_EXCEPTION(RuntimeWarning, Warning)
+    MP_DEFINE_EXCEPTION(SyntaxWarning, Warning)
+    MP_DEFINE_EXCEPTION(UserWarning, Warning)
+    MP_DEFINE_EXCEPTION(FutureWarning, Warning)
+    MP_DEFINE_EXCEPTION(ImportWarning, Warning)
+    MP_DEFINE_EXCEPTION(UnicodeWarning, Warning)
+    MP_DEFINE_EXCEPTION(BytesWarning, Warning)
+    MP_DEFINE_EXCEPTION(ResourceWarning, Warning)
 
 mp_obj_t mp_obj_new_exception(const mp_obj_type_t *exc_type) {
     return mp_obj_new_exception_msg_varg(exc_type, NULL);
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index 0e0479e..96d94d9 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -34,21 +34,64 @@
 Q(StopIteration)
 
 Q(BaseException)
+Q(ArithmeticError)
 Q(AssertionError)
 Q(AttributeError)
+Q(BlockingIOError)
+Q(BrokenPipeError)
+Q(BufferError)
+Q(BytesWarning)
+Q(ChildProcessError)
+Q(ConnectionAbortedError)
+Q(ConnectionError)
+Q(ConnectionRefusedError)
+Q(ConnectionResetError)
+Q(DeprecationWarning)
+Q(EOFError)
+Q(EnvironmentError)
+Q(Exception)
+Q(FileExistsError)
+Q(FileNotFoundError)
+Q(FloatingPointError)
+Q(FutureWarning)
+Q(GeneratorExit)
+Q(IOError)
 Q(ImportError)
+Q(ImportWarning)
 Q(IndentationError)
 Q(IndexError)
+Q(InterruptedError)
+Q(IsADirectoryError)
 Q(KeyError)
+Q(LookupError)
+Q(MemoryError)
 Q(NameError)
+Q(NotADirectoryError)
 Q(NotImplementedError)
 Q(OSError)
-Q(SyntaxError)
-Q(TypeError)
-Q(ValueError)
 Q(OverflowError)
+Q(PendingDeprecationWarning)
+Q(PermissionError)
+Q(ProcessLookupError)
+Q(ReferenceError)
+Q(ResourceWarning)
+Q(RuntimeError)
+Q(RuntimeWarning)
+Q(SyntaxError)
+Q(SyntaxWarning)
+Q(SystemError)
+Q(SystemExit)
+Q(TabError)
+Q(TimeoutError)
+Q(TypeError)
+Q(UnboundLocalError)
+Q(UnicodeWarning)
+Q(UserWarning)
+Q(ValueError)
+Q(Warning)
 Q(ZeroDivisionError)
 
+
 Q(NoneType)
 
 Q(abs)
diff --git a/py/runtime.c b/py/runtime.c
index 68edf54..1cc1c2e 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -142,23 +142,49 @@
 
     // built-in exceptions
     { MP_QSTR_BaseException, (mp_obj_t)&mp_type_BaseException },
+    { MP_QSTR_ArithmeticError, (mp_obj_t)&mp_type_ArithmeticError },
     { MP_QSTR_AssertionError, (mp_obj_t)&mp_type_AssertionError },
     { MP_QSTR_AttributeError, (mp_obj_t)&mp_type_AttributeError },
+    { MP_QSTR_BufferError, (mp_obj_t)&mp_type_BufferError },
+    { MP_QSTR_BytesWarning, (mp_obj_t)&mp_type_BytesWarning },
+    { MP_QSTR_DeprecationWarning, (mp_obj_t)&mp_type_DeprecationWarning },
+    { MP_QSTR_EOFError, (mp_obj_t)&mp_type_EOFError },
+    { MP_QSTR_EnvironmentError, (mp_obj_t)&mp_type_EnvironmentError },
+    { MP_QSTR_Exception, (mp_obj_t)&mp_type_Exception },
+    { MP_QSTR_FloatingPointError, (mp_obj_t)&mp_type_FloatingPointError },
+    { MP_QSTR_FutureWarning, (mp_obj_t)&mp_type_FutureWarning },
+    { MP_QSTR_GeneratorExit, (mp_obj_t)&mp_type_GeneratorExit },
+    { MP_QSTR_IOError, (mp_obj_t)&mp_type_IOError },
     { MP_QSTR_ImportError, (mp_obj_t)&mp_type_ImportError },
+    { MP_QSTR_ImportWarning, (mp_obj_t)&mp_type_ImportWarning },
     { MP_QSTR_IndentationError, (mp_obj_t)&mp_type_IndentationError },
     { MP_QSTR_IndexError, (mp_obj_t)&mp_type_IndexError },
     { MP_QSTR_KeyError, (mp_obj_t)&mp_type_KeyError },
+    { MP_QSTR_LookupError, (mp_obj_t)&mp_type_LookupError },
+    { MP_QSTR_MemoryError, (mp_obj_t)&mp_type_MemoryError },
     { MP_QSTR_NameError, (mp_obj_t)&mp_type_NameError },
+    { MP_QSTR_NotImplementedError, (mp_obj_t)&mp_type_NotImplementedError },
+    { MP_QSTR_OSError, (mp_obj_t)&mp_type_OSError },
+    { MP_QSTR_OverflowError, (mp_obj_t)&mp_type_OverflowError },
+    { MP_QSTR_PendingDeprecationWarning, (mp_obj_t)&mp_type_PendingDeprecationWarning },
+    { MP_QSTR_ReferenceError, (mp_obj_t)&mp_type_ReferenceError },
+    { MP_QSTR_ResourceWarning, (mp_obj_t)&mp_type_ResourceWarning },
+    { MP_QSTR_RuntimeError, (mp_obj_t)&mp_type_RuntimeError },
+    { MP_QSTR_RuntimeWarning, (mp_obj_t)&mp_type_RuntimeWarning },
     { MP_QSTR_SyntaxError, (mp_obj_t)&mp_type_SyntaxError },
+    { MP_QSTR_SyntaxWarning, (mp_obj_t)&mp_type_SyntaxWarning },
+    { MP_QSTR_SystemError, (mp_obj_t)&mp_type_SystemError },
+    { MP_QSTR_SystemExit, (mp_obj_t)&mp_type_SystemExit },
+    { MP_QSTR_TabError, (mp_obj_t)&mp_type_TabError },
     { MP_QSTR_TypeError, (mp_obj_t)&mp_type_TypeError },
+    { MP_QSTR_UnboundLocalError, (mp_obj_t)&mp_type_UnboundLocalError },
+    { MP_QSTR_UserWarning, (mp_obj_t)&mp_type_UserWarning },
     { MP_QSTR_ValueError, (mp_obj_t)&mp_type_ValueError },
+    { MP_QSTR_Warning, (mp_obj_t)&mp_type_Warning },
+    { MP_QSTR_ZeroDivisionError, (mp_obj_t)&mp_type_ZeroDivisionError },
+    { MP_QSTR_StopIteration, (mp_obj_t)&mp_type_StopIteration },
     // Somehow CPython managed to have OverflowError not inherit from ValueError ;-/
     // TODO: For MICROPY_CPYTHON_COMPAT==0 use ValueError to avoid exc proliferation
-    { MP_QSTR_OverflowError, (mp_obj_t)&mp_type_OverflowError },
-    { MP_QSTR_OSError, (mp_obj_t)&mp_type_OSError },
-    { MP_QSTR_NotImplementedError, (mp_obj_t)&mp_type_NotImplementedError },
-    { MP_QSTR_StopIteration, (mp_obj_t)&mp_type_StopIteration },
-    { MP_QSTR_ZeroDivisionError, (mp_obj_t)&mp_type_ZeroDivisionError },
 
     // Extra builtins as defined by a port
     MICROPY_EXTRA_BUILTINS