altos: expose set of available stdio values

This lets external code manipulate which connection to communicate
over.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/ao.h b/src/ao.h
index 64f33f0b..2d2bbf82 100644
--- a/src/ao.h
+++ b/src/ao.h
@@ -1169,6 +1169,9 @@ struct ao_stdio {
 	void	(*flush)(void);
 };
 
+extern __data int8_t ao_cur_stdio;
+extern __data int8_t ao_num_stdios;
+
 void
 flush(void);