tjh.dev
Linux kernel mirror (for testing)
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linux
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
22static char ppbuf[1024];
23
24void 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
36void 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}