mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 02:52:56 +00:00
de880632fc
With printch() the console messages are sent out one character at a time which is agonizingly slow especially with semihosting as the whole trap intercept, remote byte access, and system resume danse is performed for every single character across a relatively slow remote debug connection. Let's use printascii() to send a whole string at once. This is also going to be more efficient, albeit to a quite lesser extent, with serial ports as well. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
/*
|
|
* linux/arch/arm/kernel/early_printk.c
|
|
*
|
|
* Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#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);
|