Dave Hylands 5b7fd20fea Add support for storing args during an exception raised by an irq.
The user code should call micropython.alloc_emergency_exception_buf(size)
where size is the size of the buffer used to print the argument
passed to the exception.

With the test code from #732, and a call to
micropython.alloc_emergenncy_exception_buf(100) the following error is
now printed:
```python
>>> import heartbeat_irq
Uncaught exception in Timer(4) interrupt handler
Traceback (most recent call last):
  File "0://heartbeat_irq.py", line 14, in heartbeat_cb
NameError: name 'led' is not defined
```
2014-07-25 14:00:06 -07:00
..
2014-04-20 00:16:30 +01:00
2014-03-11 23:55:41 -07:00
2014-05-02 23:03:23 +01:00
2014-07-03 13:25:24 +01:00
2014-07-19 16:39:13 +01:00
2014-07-19 16:39:13 +01:00
2014-03-12 18:15:55 -07:00
2014-06-15 00:41:47 +01:00
2014-07-03 13:25:24 +01:00
2014-06-30 16:31:06 +02:00
2014-07-19 16:39:13 +01:00
2014-07-19 16:39:13 +01:00
2014-06-15 22:48:05 -07:00
2014-07-03 13:25:24 +01:00
2014-07-03 13:25:24 +01:00
2014-07-03 13:25:24 +01:00
2014-03-11 23:55:41 -07:00
2014-06-02 21:43:02 +02:00