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Commit 459192c9 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

[PATCH] x86-64: Add simnow console 



This adds console and earlyprintk support for a host file
on AMD's SimNow simulator.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e5bc8b6b

arch/x86_64/kernel/early_printk.c

+46 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/tty.h>

#include <asm/io.h>

#include <asm/processor.h>

#include <asm/fcntl.h>



/* Simple VGA output */
@@ -158,6 +159,47 @@ static struct console early_serial_console = { 
	.index =	-1,

};



/* Console interface to a host file on AMD's SimNow! */



static int simnow_fd;



enum {

	MAGIC1 = 0xBACCD00A,

	MAGIC2 = 0xCA110000,

	XOPEN = 5,

	XWRITE = 4,

};



static noinline long simnow(long cmd, long a, long b, long c)

{

	long ret;

	asm volatile("cpuid" :

		     "=a" (ret) :

		     "b" (a), "c" (b), "d" (c), "0" (MAGIC1), "D" (cmd + MAGIC2));

	return ret;

}



void __init simnow_init(char *str)

{

	char *fn = "klog";

	if (*str == '=')

		fn = ++str;

	/* error ignored */

	simnow_fd = simnow(XOPEN, (unsigned long)fn, O_WRONLY|O_APPEND|O_CREAT, 0644);

}



static void simnow_write(struct console *con, const char *s, unsigned n)

{

	simnow(XWRITE, simnow_fd, (unsigned long)s, n);

}



static struct console simnow_console = {

	.name =		"simnow",

	.write =	simnow_write,

	.flags =	CON_PRINTBUFFER,

	.index =	-1,

};



/* Direct interface for emergencies */

struct console *early_console = &early_vga_console;

static int early_console_initialized = 0;
@@ -205,6 +247,10 @@ int __init setup_early_printk(char *opt) 
		max_xpos = SCREEN_INFO.orig_video_cols;

		max_ypos = SCREEN_INFO.orig_video_lines;

		early_console = &early_vga_console; 

 	} else if (!strncmp(buf, "simnow", 6)) {

 		simnow_init(buf + 6);

 		early_console = &simnow_console;

 		keep_early = 1;

	}

	early_console_initialized = 1;

	register_console(early_console);