Add USART support, connected to stdio for REPL.

1 files changed, 7 insertions, 0 deletions

diff --git a/stm/usart.h b/stm/usart.h
new file mode 100644
index 000000000..9d92e59f5
--- /dev/null
+++ b/stm/usart.h
@@ -0,0 +1,7 @@
+void usart_init(void);
+bool usart_is_enabled(void);
+bool usart_rx_any(void);
+int usart_rx_char(void);
+void usart_tx_char(int c);
+void usart_tx_str(const char *str);
+void usart_tx_strn_cooked(const char *str, int len);