1 files changed, 64 insertions, 0 deletions
diff --git a/kern/printk.c b/kern/printk.c
new file mode 100644
index 00000000..fc609c3c
--- /dev/null
+++ b/kern/printk.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2010 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <kern/printk.h>
+#include <lib/sprintf.h>
+#include <machine/cpu.h>
+
+/*
+ * Size of the static buffer.
+ */
+#define PRINTK_BUFSIZE 1024
+
+/*
+ * XXX Must be provided by a console driver.
+ */
+extern void console_write_byte(char c);
+
+static char printk_buffer[PRINTK_BUFSIZE];
+
+int
+printk(const char *format, ...)
+{
+    va_list ap;
+    int length;
+
+    va_start(ap, format);
+    length = vprintk(format, ap);
+    va_end(ap);
+
+    return length;
+}
+
+int
+vprintk(const char *format, va_list ap)
+{
+    unsigned long flags;
+    int length;
+    char *ptr;
+
+    flags = cpu_intr_save();
+
+    length = vsnprintf(printk_buffer, sizeof(printk_buffer), format, ap);
+
+    for (ptr = printk_buffer; *ptr != '\0'; ptr++)
+        console_write_byte(*ptr);
+
+    cpu_intr_restore(flags);
+
+    return length;
+}