arch/mips/arc/promlib.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) 1996 David S. Miller (dm@sgi.com)
   7  * Compability with board caches, Ulf Carlsson
   8  */
   9 #include <linux/kernel.h>
  10 #include <asm/sgialib.h>
  11 #include <asm/bcache.h>
  12
  13 /*
  14  * IP22 boardcache is not compatible with board caches.  Thus we disable it
  15  * during romvec action.  Since r4xx0.c is always compiled and linked with your
  16  * kernel, this shouldn't cause any harm regardless what MIPS processor you
  17  * have.
  18  *
  19  * The ARC write and read functions seem to interfere with the serial lines
  20  * in some way. You should be careful with them.
  21  */
  22
  23 void prom_putchar(char c)
  24 {
  25         ULONG cnt;
  26         CHAR it = c;
  27
  28         bc_disable();
  29         ArcWrite(1, &it, 1, &cnt);
  30         bc_enable();
  31 }
  32
  33 char prom_getchar(void)
  34 {
  35         ULONG cnt;
  36         CHAR c;
  37
  38         bc_disable();
  39         ArcRead(0, &c, 1, &cnt);
  40         bc_enable();
  41
  42         return c;
  43 }