Add display/printk to fusee stage2

fusee/fusee-secondary/src/lib/printk.c

@@ -0,0 +1,24 @@
+/**
+ * Kernel print functions.
+ */
+
+#include "printk.h"
+
+#include "vsprintf.h"
+#include "../display/video_fb.h"
+
+/**
+ * Temporary stand-in main printk.
+ *
+ * TODO: This should print via UART, console framebuffer, and to a ring for
+ * consumption by Horizon
+ */
+void printk(char *fmt, ...)
+{
+	va_list list;
+	char buf[512];
+	va_start(list, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, list);
+	video_puts(buf);
+	va_end(list);
+}