early_printk.c
// 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);