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