93fd03a8c6
This patch allows an earlyprintk console if CONFIG_DEBUG_LL is enabled, using the printch asm function. The patch is based on the original work by Sascha Hauer. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Pavel Machek <pavel@ucw.cz>
57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
/*
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* linux/arch/arm/kernel/early_printk.c
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*
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* Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/console.h>
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#include <linux/init.h>
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extern void printch(int);
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static void early_write(const char *s, unsigned n)
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{
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while (n-- > 0) {
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if (*s == '\n')
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printch('\r');
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printch(*s);
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s++;
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}
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}
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static void early_console_write(struct console *con, const char *s, unsigned n)
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{
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early_write(s, n);
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}
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static struct console early_console = {
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.name = "earlycon",
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.write = early_console_write,
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.flags = CON_PRINTBUFFER | CON_BOOT,
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.index = -1,
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};
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asmlinkage void early_printk(const char *fmt, ...)
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{
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char buf[512];
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int n;
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va_list ap;
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va_start(ap, fmt);
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n = vscnprintf(buf, sizeof(buf), fmt, ap);
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early_write(buf, n);
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va_end(ap);
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}
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static int __init setup_early_printk(char *buf)
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{
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register_console(&early_console);
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return 0;
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}
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early_param("earlyprintk", setup_early_printk);
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