linux/arch/sh/kernel/early_printk.c

86 lines
1.8 KiB
C

/*
* arch/sh/kernel/early_printk.c
*
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2002 M. R. Brown
* Copyright (C) 2004 - 2007 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <asm/sh_bios.h>
/*
* Print a string through the BIOS
*/
static void sh_console_write(struct console *co, const char *s,
unsigned count)
{
sh_bios_console_write(s, count);
}
/*
* Setup initial baud/bits/parity. We do two things here:
* - construct a cflag setting for the first rs_open()
* - initialize the serial port
* Return non-zero if we didn't find a serial port.
*/
static int __init sh_console_setup(struct console *co, char *options)
{
int cflag = CREAD | HUPCL | CLOCAL;
/*
* Now construct a cflag setting.
* TODO: this is a totally bogus cflag, as we have
* no idea what serial settings the BIOS is using, or
* even if its using the serial port at all.
*/
cflag |= B115200 | CS8 | /*no parity*/0;
co->cflag = cflag;
return 0;
}
static struct console bios_console = {
.name = "bios",
.write = sh_console_write,
.setup = sh_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static struct console *early_console;
static int __init setup_early_printk(char *buf)
{
int keep_early = 0;
if (!buf)
return 0;
if (strstr(buf, "keep"))
keep_early = 1;
if (!strncmp(buf, "bios", 4))
early_console = &bios_console;
if (likely(early_console)) {
if (keep_early)
early_console->flags &= ~CON_BOOT;
else
early_console->flags |= CON_BOOT;
register_console(early_console);
}
return 0;
}
early_param("earlyprintk", setup_early_printk);