release/src-rt-6.x/linux/linux-2.6/arch/sparc/prom/printf.c

   1 /*
   2  * printf.c:  Internal prom library printf facility.
   3  *
   4  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
   6  *
   7  * We used to warn all over the code: DO NOT USE prom_printf(),
   8  * and yet people do. Anton's banking code was outputting banks
   9  * with prom_printf for most of the 2.4 lifetime. Since an effective
  10  * stick is not available, we deployed a carrot: an early printk
  11  * through PROM by means of -p boot option. This ought to fix it.
  12  * USE printk; if you need, deploy -p.
  13  */
  14
  15 #include <linux/kernel.h>
  16
  17 #include <asm/openprom.h>
  18 #include <asm/oplib.h>
  19
  20 static char ppbuf[1024];
  21
  22 void
  23 prom_write(const char *buf, unsigned int n)
  24 {
  25         char ch;
  26
  27         while (n != 0) {
  28                 --n;
  29                 if ((ch = *buf++) == '\n')
  30                         prom_putchar('\r');
  31                 prom_putchar(ch);
  32         }
  33 }
  34
  35 void
  36 prom_printf(char *fmt, ...)
  37 {
  38         va_list args;
  39         int i;
  40
  41         va_start(args, fmt);
  42         i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args);
  43         va_end(args);
  44
  45         prom_write(ppbuf, i);
  46 }