3 files changed, 55 insertions, 0 deletions
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
new file mode 100644
index 0000000..32391b8
--- /dev/null
+++ b/libc/include/stdio.h
@@ -0,0 +1,3 @@
+int printf(const char* fmt, ...);
+int puts(const char*);
+int putchar(int);
diff --git a/libc/include/string.h b/libc/include/string.h
new file mode 100644
index 0000000..650a7ac
--- /dev/null
+++ b/libc/include/string.h
@@ -0,0 +1,3 @@
+#include <stddef.h>
+int strlen(const char*);
+void* memset(void*, int, size_t);
diff --git a/libc/stdio.c b/libc/stdio.c
new file mode 100644
index 0000000..4888338
--- /dev/null
+++ b/libc/stdio.c
@@ -0,0 +1,49 @@
+#include "stdio.h"
+#include "tty.h"
+#include <stdarg.h>
+
+int putchar(int ch)
+{
+    tty_putchar((char)ch);
+    return 0;
+}
+
+int puts(const char* str)
+{
+    tty_puts(str);
+    return 0;
+}
+
+int printf(const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    while(*fmt)
+    {
+        char ch = *fmt++;
+        switch(ch)
+        {
+        case '%':
+        {
+            switch(*fmt++)
+            {
+            case 'c':
+                putchar(va_arg(ap, int));
+                break;
+            case 's':
+                puts(va_arg(ap, const char*));
+                break;
+            default:
+                puts("printf: unknown format\n");
+                break;
+            }
+            break;
+        }
+        default:
+            putchar(ch);
+            break;
+        }
+    }
+    va_end(ap);
+    return 0;
+}