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 } 47