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 #include <linux/module.h> 17 18 #include <asm/openprom.h> 19 #include <asm/oplib.h> 20 21 static char ppbuf[1024]; 22 23 void 24 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 37 prom_printf(char *fmt, ...) 38 { 39 va_list args; 40 int i; 41 42 va_start(args, fmt); 43 i = vscnprintf(ppbuf, sizeof(ppbuf), fmt, args); 44 va_end(args); 45 46 prom_write(ppbuf, i); 47 } 48 EXPORT_SYMBOL(prom_printf); 49