xref: /openbmc/linux/arch/um/drivers/stderr_console.c (revision 87c2ce3b)
1 #include <linux/init.h>
2 #include <linux/console.h>
3 
4 #include "chan_user.h"
5 
6 /* ----------------------------------------------------------------------------- */
7 /* trivial console driver -- simply dump everything to stderr                    */
8 
9 /*
10  * Don't register by default -- as this registeres very early in the
11  * boot process it becomes the default console.  And as this isn't a
12  * real tty driver init isn't able to open /dev/console then.
13  *
14  * In most cases this isn't what you want ...
15  */
16 static int use_stderr_console = 0;
17 
18 static void stderr_console_write(struct console *console, const char *string,
19 				 unsigned len)
20 {
21 	generic_write(2 /* stderr */, string, len, NULL);
22 }
23 
24 static struct console stderr_console = {
25 	.name		= "stderr",
26 	.write		= stderr_console_write,
27 	.flags		= CON_PRINTBUFFER,
28 };
29 
30 static int __init stderr_console_init(void)
31 {
32 	if (use_stderr_console)
33 		register_console(&stderr_console);
34 	return 0;
35 }
36 console_initcall(stderr_console_init);
37 
38 static int stderr_setup(char *str)
39 {
40 	if (!str)
41 		return 0;
42 	use_stderr_console = simple_strtoul(str,&str,0);
43 	return 1;
44 }
45 __setup("stderr=", stderr_setup);
46