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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 outputing 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
20static char ppbuf[1024];
21
22void
23prom_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
35void
36prom_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}