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) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   6  * Copyright (c) 2002 Pete Zaitcev (zaitcev@yahoo.com)
   7  *
   8  * We used to warn all over the code: DO NOT USE prom_printf(),
   9  * and yet people do. Anton's banking code was outputting banks
  10  * with prom_printf for most of the 2.4 lifetime. Since an effective
  11  * stick is not available, we deployed a carrot: an early printk
  12  * through PROM by means of -p boot option. This ought to fix it.
  13  * USE printk; if you need, deploy -p.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/compiler.h>
  18
  19 #include <asm/openprom.h>
  20 #include <asm/oplib.h>
  21
  22 static char ppbuf[1024];
  23
  24 void notrace prom_write(const char *buf, unsigned int n)
  25 {
  26         char ch;
  27
  28         while (n != 0) {
  29                 --n;
  30                 if ((ch = *buf++) == '\n')
  31                         prom_putchar('\r');
  32                 prom_putchar(ch);
  33         }
  34 }
  35
  36 void notrace prom_printf(const 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 }