arch/um/drivers/stderr_console.c

   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);