1 files changed, 47 insertions, 0 deletions
diff --git a/arch/arm/kernel/early_printk.c b/arch/arm/kernel/early_printk.c
new file mode 100644
index 000000000..03239ca0d
--- /dev/null
+++ b/arch/arm/kernel/early_printk.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/arch/arm/kernel/early_printk.c
+ *
+ *  Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/string.h>
+
+extern void printascii(const char *);
+
+static void early_write(const char *s, unsigned n)
+{
+	char buf[128];
+	while (n) {
+		unsigned l = min(n, sizeof(buf)-1);
+		memcpy(buf, s, l);
+		buf[l] = 0;
+		s += l;
+		n -= l;
+		printascii(buf);
+	}
+}
+
+static void early_console_write(struct console *con, const char *s, unsigned n)
+{
+	early_write(s, n);
+}
+
+static struct console early_console_dev = {
+	.name =		"earlycon",
+	.write =	early_console_write,
+	.flags =	CON_PRINTBUFFER | CON_BOOT,
+	.index =	-1,
+};
+
+static int __init setup_early_printk(char *buf)
+{
+	early_console = &early_console_dev;
+	register_console(&early_console_dev);
+	return 0;
+}
+
+early_param("earlyprintk", setup_early_printk);