arch/m68k/kernel/early_printk.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (c) 2014 Finn Thain
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/console.h>
  11 #include <linux/init.h>
  12 #include <linux/string.h>
  13 #include <asm/setup.h>
  14
  15 extern void mvme16x_cons_write(struct console *co,
  16                                const char *str, unsigned count);
  17
  18 asmlinkage void __init debug_cons_nputs(const char *s, unsigned n);
  19
  20 static void __ref debug_cons_write(struct console *c,
  21                                    const char *s, unsigned n)
  22 {
  23 #if !(defined(CONFIG_SUN3) || defined(CONFIG_M68000) || \
  24       defined(CONFIG_COLDFIRE))
  25         if (MACH_IS_MVME16x)
  26                 mvme16x_cons_write(c, s, n);
  27         else
  28                 debug_cons_nputs(s, n);
  29 #endif
  30 }
  31
  32 static struct console early_console_instance = {
  33         .name  = "debug",
  34         .write = debug_cons_write,
  35         .flags = CON_PRINTBUFFER | CON_BOOT,
  36         .index = -1
  37 };
  38
  39 static int __init setup_early_printk(char *buf)
  40 {
  41         if (early_console || buf)
  42                 return 0;
  43
  44         early_console = &early_console_instance;
  45         register_console(early_console);
  46
  47         return 0;
  48 }
  49 early_param("earlyprintk", setup_early_printk);
  50
  51 /*
  52  * debug_cons_nputs() defined in arch/m68k/kernel/head.S cannot be called
  53  * after init sections are discarded (for platforms that use it).
  54  */
  55 #if !(defined(CONFIG_SUN3) || defined(CONFIG_M68000) || \
  56       defined(CONFIG_COLDFIRE))
  57
  58 static int __init unregister_early_console(void)
  59 {
  60         if (!early_console || MACH_IS_MVME16x)
  61                 return 0;
  62
  63         return unregister_console(early_console);
  64 }
  65 late_initcall(unregister_early_console);
  66
  67 #endif