1 files changed, 34 insertions, 0 deletions
diff --git a/shared/usart_stdio.c b/shared/usart_stdio.c
new file mode 100644
index 0000000..6a6866e
--- /dev/null
+++ b/shared/usart_stdio.c
@@ -0,0 +1,34 @@
+/*
+ * support for stdio output to a usart
+ * Karl Palsson, 2015 <karlp@tweak.net.au>
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <libopencm3/stm32/usart.h>
+
+#ifndef STDIO_USART
+#define STDIO_USART USART1
+#endif
+
+int _write(int file, char *ptr, int len);
+int _write(int file, char *ptr, int len)
+{
+	int i;
+
+	if (file == STDOUT_FILENO || file == STDERR_FILENO) {
+		for (i = 0; i < len; i++) {
+			if (ptr[i] == '\n') {
+				usart_send_blocking(STDIO_USART, '\r');
+			}
+			usart_send_blocking(STDIO_USART, ptr[i]);
+		}
+		return i;
+	}
+	errno = EIO;
+	return -1;
+}
+
+